PYTHON-3288 Implement client side operation timeout (#954)

Add timeoutMS URI option and MongoClient keyword argument.
Add provisional/beta pymongo.timeout() api to set a deadline for a block of operations.

.evergreen/resync-specs.sh

@@ -105,6 +105,9 @@ do
     crud|CRUD)
       cpjson crud/tests/ crud
       ;;
+    csot|CSOT|client-side-operations-timeout)
+      cpjson client-side-operations-timeout/tests csot
+      ;;
     load-balancers|load_balancer)
       cpjson load-balancers/tests load_balancer
       ;;
@@ -150,6 +153,7 @@ do
       ;;
     uri|uri-options|uri_options)
       cpjson uri-options/tests uri_options
+      cp "$SPECS"/source/uri-options/tests/*.pem  $PYMONGO/test/uri_options
       ;;
     stable-api|versioned-api)
       cpjson versioned-api/tests versioned-api

doc/api/pymongo/index.rst

@@ -22,6 +22,8 @@
 
       The maximum wire protocol version PyMongo supports.
 
+   .. autofunction:: timeout
+
 Sub-modules:
 
 .. toctree::

doc/changelog.rst

@@ -6,6 +6,13 @@ Changes in Version 4.2
 
 .. warning:: PyMongo 4.2 drops support for Python 3.6: Python 3.7+ is now required.
 
+PyMongo 4.2 brings a number of improvements including:
+
+- Support for MongoDB 6.0.
+- Provisional (beta) support for :func:`pymongo.timeout` to apply a single timeout
+  to an entire block of pymongo operations.
+- Beta support for Queryable Encryption with MongoDB 6.0.
+
 Bug fixes
 .........
 

pymongo/__init__.py

@@ -14,7 +14,7 @@
 
 """Python driver for MongoDB."""
 
-from typing import Tuple, Union
+from typing import ContextManager, Optional, Tuple, Union
 
 ASCENDING = 1
 """Ascending sort order."""
@@ -69,6 +69,7 @@ version = __version__
 
 """Current version of PyMongo."""
 
+from pymongo import _csot
 from pymongo.collection import ReturnDocument  # noqa: F401
 from pymongo.common import (  # noqa: F401
     MAX_SUPPORTED_WIRE_VERSION,
@@ -97,3 +98,47 @@ def has_c() -> bool:
         return True
     except ImportError:
         return False
+
+
+def timeout(seconds: Optional[float]) -> ContextManager:
+    """**(Provisional)** Apply the given timeout for a block of operations.
+
+    .. note:: :func:`~pymongo.timeout` is currently provisional. Backwards
+       incompatible changes may occur before becoming officially supported.
+
+    Use :func:`~pymongo.timeout` in a with-statement::
+
+      with pymongo.timeout(5):
+          client.db.coll.insert_one({})
+          client.db.coll2.insert_one({})
+
+    When the with-statement is entered, a deadline is set for the entire
+    block. When that deadline is exceeded, any blocking pymongo operation
+    will raise a timeout exception. For example::
+
+      try:
+          with pymongo.timeout(5):
+              client.db.coll.insert_one({})
+              time.sleep(5)
+              # The deadline has now expired, the next operation will raise
+              # a timeout exception.
+              client.db.coll2.insert_one({})
+      except (ServerSelectionTimeoutError, ExecutionTimeout, WTimeoutError,
+              NetworkTimeout) as exc:
+          print(f"block timed out: {exc!r}")
+
+    :Parameters:
+      - `seconds`: A non-negative floating point number expressing seconds, or None.
+
+    :Raises:
+      - :py:class:`ValueError`: When `seconds` is negative.
+
+    .. versionadded:: 4.2
+    """
+    if not isinstance(seconds, (int, float, type(None))):
+        raise TypeError("timeout must be None, an int, or a float")
+    if seconds and seconds < 0:
+        raise ValueError("timeout cannot be negative")
+    if seconds is not None:
+        seconds = float(seconds)
+    return _csot._TimeoutContext(seconds)

pymongo/_csot.py

@@ -0,0 +1,80 @@
+# Copyright 2022-present MongoDB, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you
+# may not use this file except in compliance with the License.  You
+# may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.  See the License for the specific language governing
+# permissions and limitations under the License.
+
+"""Internal helpers for CSOT."""
+
+import time
+from contextvars import ContextVar
+from typing import Optional
+
+TIMEOUT: ContextVar[Optional[float]] = ContextVar("TIMEOUT", default=None)
+RTT: ContextVar[float] = ContextVar("RTT", default=0.0)
+DEADLINE: ContextVar[float] = ContextVar("DEADLINE", default=float("inf"))
+
+
+def get_timeout() -> Optional[float]:
+    return TIMEOUT.get(None)
+
+
+def get_rtt() -> float:
+    return RTT.get()
+
+
+def get_deadline() -> float:
+    return DEADLINE.get()
+
+
+def set_rtt(rtt: float) -> None:
+    RTT.set(rtt)
+
+
+def set_timeout(timeout: Optional[float]) -> None:
+    TIMEOUT.set(timeout)
+    DEADLINE.set(time.monotonic() + timeout if timeout else float("inf"))
+
+
+def remaining() -> Optional[float]:
+    if not get_timeout():
+        return None
+    return DEADLINE.get() - time.monotonic()
+
+
+def clamp_remaining(max_timeout: float) -> float:
+    """Return the remaining timeout clamped to a max value."""
+    timeout = remaining()
+    if timeout is None:
+        return max_timeout
+    return min(timeout, max_timeout)
+
+
+class _TimeoutContext(object):
+    """Internal timeout context manager.
+
+    Use :func:`pymongo.timeout` instead::
+
+      with client.timeout(0.5):
+          client.test.test.insert_one({})
+    """
+
+    __slots__ = ("_timeout",)
+
+    def __init__(self, timeout: Optional[float]):
+        self._timeout = timeout
+
+    def __enter__(self):
+        set_timeout(self._timeout)
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        set_timeout(None)

pymongo/bulk.py

@@ -330,6 +330,8 @@ class _Bulk(object):
                     session._apply_to(cmd, retryable, ReadPreference.PRIMARY, sock_info)
                 sock_info.send_cluster_time(cmd, session, client)
                 sock_info.add_server_api(cmd)
+                # CSOT: apply timeout before encoding the command.
+                sock_info.apply_timeout(client, cmd)
                 ops = islice(run.ops, run.idx_offset, None)
 
                 # Run as many ops as possible in one command.

pymongo/client_options.py

@@ -14,6 +14,8 @@
 
 """Tools to parse mongo client options."""
 
+from typing import Optional
+
 from bson.codec_options import _parse_codec_options
 from pymongo import common
 from pymongo.auth import _build_credentials_tuple
@@ -195,6 +197,7 @@ class ClientOptions(object):
         self.__server_selector = options.get("server_selector", any_server_selector)
         self.__auto_encryption_opts = options.get("auto_encryption_opts")
         self.__load_balanced = options.get("loadbalanced")
+        self.__timeout = options.get("timeoutms")
 
     @property
     def _options(self):
@@ -260,6 +263,14 @@ class ClientOptions(object):
         """A :class:`~pymongo.read_concern.ReadConcern` instance."""
         return self.__read_concern
 
+    @property
+    def timeout(self) -> Optional[float]:
+        """The timeout.
+
+        ..versionadded: 4.2
+        """
+        return self.__timeout
+
     @property
     def retry_writes(self):
         """If this instance should retry supported write operations."""

pymongo/client_session.py

@@ -150,6 +150,7 @@ from bson.binary import Binary
 from bson.int64 import Int64
 from bson.son import SON
 from bson.timestamp import Timestamp
+from pymongo import _csot
 from pymongo.cursor import _SocketManager
 from pymongo.errors import (
     ConfigurationError,
@@ -826,7 +827,7 @@ class ClientSession:
         wc = opts.write_concern
         cmd = SON([(command_name, 1)])
         if command_name == "commitTransaction":
-            if opts.max_commit_time_ms:
+            if opts.max_commit_time_ms and _csot.get_timeout() is None:
                 cmd["maxTimeMS"] = opts.max_commit_time_ms
 
             # Transaction spec says that after the initial commit attempt,

pymongo/collection.py

@@ -116,6 +116,7 @@ class Collection(common.BaseObject, Generic[_DocumentType]):
         write_concern: Optional[WriteConcern] = None,
         read_concern: Optional["ReadConcern"] = None,
         session: Optional["ClientSession"] = None,
+        timeout: Optional[float] = None,
         encrypted_fields: Optional[Mapping[str, Any]] = None,
         **kwargs: Any,
     ) -> None:
@@ -198,6 +199,7 @@ class Collection(common.BaseObject, Generic[_DocumentType]):
             read_preference or database.read_preference,
             write_concern or database.write_concern,
             read_concern or database.read_concern,
+            timeout if timeout is not None else database.timeout,
         )
         if not isinstance(name, str):
             raise TypeError("name must be an instance of str")
@@ -390,6 +392,7 @@ class Collection(common.BaseObject, Generic[_DocumentType]):
         read_preference: Optional[_ServerMode] = None,
         write_concern: Optional[WriteConcern] = None,
         read_concern: Optional["ReadConcern"] = None,
+        timeout: Optional[float] = None,
     ) -> "Collection[_DocumentType]":
         """Get a clone of this collection changing the specified settings.
 
@@ -428,6 +431,7 @@ class Collection(common.BaseObject, Generic[_DocumentType]):
             read_preference or self.read_preference,
             write_concern or self.write_concern,
             read_concern or self.read_concern,
+            timeout=timeout if timeout is not None else self.timeout,
         )
 
     def bulk_write(

pymongo/common.py

@@ -339,6 +339,15 @@ def validate_timeout_or_none_or_zero(option: Any, value: Any) -> Optional[float]
     return validate_positive_float(option, value) / 1000.0
 
 
+def validate_timeoutms(option: Any, value: Any) -> Optional[float]:
+    """Validates a timeout specified in milliseconds returning
+    a value in floating point seconds.
+    """
+    if value is None:
+        return None
+    return validate_positive_float_or_zero(option, value) / 1000.0
+
+
 def validate_max_staleness(option: str, value: Any) -> int:
     """Validates maxStalenessSeconds according to the Max Staleness Spec."""
     if value == -1 or value == "-1":
@@ -658,6 +667,7 @@ URI_OPTIONS_VALIDATOR_MAP: Dict[str, Callable[[Any, Any], Any]] = {
     "zlibcompressionlevel": validate_zlib_compression_level,
     "srvservicename": validate_string,
     "srvmaxhosts": validate_non_negative_integer,
+    "timeoutms": validate_timeoutms,
 }
 
 # Dictionary where keys are the names of URI options specific to pymongo,
@@ -821,8 +831,8 @@ class BaseObject(object):
         read_preference: _ServerMode,
         write_concern: WriteConcern,
         read_concern: ReadConcern,
+        timeout: Optional[float],
     ) -> None:
-
         if not isinstance(codec_options, CodecOptions):
             raise TypeError("codec_options must be an instance of bson.codec_options.CodecOptions")
         self.__codec_options = codec_options
@@ -845,6 +855,12 @@ class BaseObject(object):
             raise TypeError("read_concern must be an instance of pymongo.read_concern.ReadConcern")
         self.__read_concern = read_concern
 
+        if not isinstance(timeout, (int, float, type(None))):
+            raise TypeError("timeout must be None, an int, or a float")
+        if timeout and timeout < 0:
+            raise TypeError("timeout cannot be negative")
+        self.__timeout = float(timeout) if timeout else None
+
     @property
     def codec_options(self) -> CodecOptions:
         """Read only access to the :class:`~bson.codec_options.CodecOptions`
@@ -894,6 +910,14 @@ class BaseObject(object):
         """
         return self.__read_concern
 
+    @property
+    def timeout(self) -> Optional[float]:
+        """Read only access to the timeout of this instance.
+
+        .. versionadded:: 4.2
+        """
+        return self.__timeout
+
 
 class _CaseInsensitiveDictionary(abc.MutableMapping):
     def __init__(self, *args, **kwargs):

pymongo/database.py

@@ -75,6 +75,7 @@ class Database(common.BaseObject, Generic[_DocumentType]):
         read_preference: Optional[_ServerMode] = None,
         write_concern: Optional["WriteConcern"] = None,
         read_concern: Optional["ReadConcern"] = None,
+        timeout: Optional[float] = None,
     ) -> None:
         """Get a database by client and name.
 
@@ -127,6 +128,7 @@ class Database(common.BaseObject, Generic[_DocumentType]):
             read_preference or client.read_preference,
             write_concern or client.write_concern,
             read_concern or client.read_concern,
+            timeout if timeout is not None else client.timeout,
         )
 
         if not isinstance(name, str):
@@ -154,6 +156,7 @@ class Database(common.BaseObject, Generic[_DocumentType]):
         read_preference: Optional[_ServerMode] = None,
         write_concern: Optional["WriteConcern"] = None,
         read_concern: Optional["ReadConcern"] = None,
+        timeout: Optional[float] = None,
     ) -> "Database[_DocumentType]":
         """Get a clone of this database changing the specified settings.
 
@@ -193,6 +196,7 @@ class Database(common.BaseObject, Generic[_DocumentType]):
             read_preference or self.read_preference,
             write_concern or self.write_concern,
             read_concern or self.read_concern,
+            timeout if timeout is not None else self.timeout,
         )
 
     def __eq__(self, other: Any) -> bool:
@@ -241,6 +245,7 @@ class Database(common.BaseObject, Generic[_DocumentType]):
         read_preference: Optional[_ServerMode] = None,
         write_concern: Optional["WriteConcern"] = None,
         read_concern: Optional["ReadConcern"] = None,
+        timeout: Optional[float] = None,
     ) -> Collection[_DocumentType]:
         """Get a :class:`~pymongo.collection.Collection` with the given name
         and options.
@@ -280,7 +285,14 @@ class Database(common.BaseObject, Generic[_DocumentType]):
             used.
         """
         return Collection(
-            self, name, False, codec_options, read_preference, write_concern, read_concern
+            self,
+            name,
+            False,
+            codec_options,
+            read_preference,
+            write_concern,
+            read_concern,
+            timeout=timeout,
         )
 
     def create_collection(
@@ -291,6 +303,7 @@ class Database(common.BaseObject, Generic[_DocumentType]):
         write_concern: Optional["WriteConcern"] = None,
         read_concern: Optional["ReadConcern"] = None,
         session: Optional["ClientSession"] = None,
+        timeout: Optional[float] = None,
         encrypted_fields: Optional[Mapping[str, Any]] = None,
         **kwargs: Any,
     ) -> Collection[_DocumentType]:
@@ -421,6 +434,7 @@ class Database(common.BaseObject, Generic[_DocumentType]):
                 write_concern,
                 read_concern,
                 session=s,
+                timeout=timeout,
                 encrypted_fields=encrypted_fields,
                 **kwargs,
             )

pymongo/encryption.py

@@ -16,6 +16,7 @@
 
 import contextlib
 import enum
+import socket
 import uuid
 import weakref
 from typing import Any, Mapping, Optional, Sequence
@@ -38,6 +39,7 @@ from bson.codec_options import CodecOptions
 from bson.errors import BSONError
 from bson.raw_bson import DEFAULT_RAW_BSON_OPTIONS, RawBSONDocument, _inflate_bson
 from bson.son import SON
+from pymongo import _csot
 from pymongo.daemon import _spawn_daemon
 from pymongo.encryption_options import AutoEncryptionOpts
 from pymongo.errors import (
@@ -47,6 +49,7 @@ from pymongo.errors import (
     ServerSelectionTimeoutError,
 )
 from pymongo.mongo_client import MongoClient
+from pymongo.network import BLOCKING_IO_ERRORS
 from pymongo.pool import PoolOptions, _configured_socket
 from pymongo.read_concern import ReadConcern
 from pymongo.ssl_support import get_ssl_context
@@ -119,9 +122,11 @@ class _EncryptionIO(MongoCryptCallback):  # type: ignore
                 False,  # allow_invalid_hostnames
                 False,
             )  # disable_ocsp_endpoint_check
+        # CSOT: set timeout for socket creation.
+        connect_timeout = max(_csot.clamp_remaining(_KMS_CONNECT_TIMEOUT), 0.001)
         opts = PoolOptions(
-            connect_timeout=_KMS_CONNECT_TIMEOUT,
-            socket_timeout=_KMS_CONNECT_TIMEOUT,
+            connect_timeout=connect_timeout,
+            socket_timeout=connect_timeout,
             ssl_context=ctx,
         )
         host, port = parse_host(endpoint, _HTTPS_PORT)
@@ -129,10 +134,14 @@ class _EncryptionIO(MongoCryptCallback):  # type: ignore
         try:
             conn.sendall(message)
             while kms_context.bytes_needed > 0:
+                # CSOT: update timeout.
+                conn.settimeout(max(_csot.clamp_remaining(_KMS_CONNECT_TIMEOUT), 0))
                 data = conn.recv(kms_context.bytes_needed)
                 if not data:
                     raise OSError("KMS connection closed")
                 kms_context.feed(data)
+        except BLOCKING_IO_ERRORS:
+            raise socket.timeout("timed out")
         finally:
             conn.close()
 

pymongo/message.py

@@ -300,6 +300,9 @@ class _Query(object):
         self._as_command = None
         self.exhaust = exhaust
 
+    def reset(self):
+        self._as_command = None
+
     def namespace(self):
         return "%s.%s" % (self.db, self.coll)
 
@@ -320,7 +323,7 @@ class _Query(object):
         sock_info.validate_session(self.client, self.session)
         return use_find_cmd
 
-    def as_command(self, sock_info):
+    def as_command(self, sock_info, apply_timeout=False):
         """Return a find command document for this query."""
         # We use the command twice: on the wire and for command monitoring.
         # Generate it once, for speed and to avoid repeating side-effects.
@@ -356,6 +359,9 @@ class _Query(object):
         client = self.client
         if client._encrypter and not client._encrypter._bypass_auto_encryption:
             cmd = client._encrypter.encrypt(self.db, cmd, self.codec_options)
+        # Support CSOT
+        if apply_timeout:
+            sock_info.apply_timeout(client, cmd)
         self._as_command = cmd, self.db
         return self._as_command
 
@@ -371,7 +377,7 @@ class _Query(object):
         spec = self.spec
 
         if use_cmd:
-            spec = self.as_command(sock_info)[0]
+            spec = self.as_command(sock_info, apply_timeout=True)[0]
             request_id, msg, size, _ = _op_msg(
                 0,
                 spec,
@@ -457,6 +463,9 @@ class _GetMore(object):
         self.exhaust = exhaust
         self.comment = comment
 
+    def reset(self):
+        self._as_command = None
+
     def namespace(self):
         return "%s.%s" % (self.db, self.coll)
 
@@ -471,7 +480,7 @@ class _GetMore(object):
         sock_info.validate_session(self.client, self.session)
         return use_cmd
 
-    def as_command(self, sock_info):
+    def as_command(self, sock_info, apply_timeout=False):
         """Return a getMore command document for this query."""
         # See _Query.as_command for an explanation of this caching.
         if self._as_command is not None:
@@ -493,6 +502,9 @@ class _GetMore(object):
         client = self.client
         if client._encrypter and not client._encrypter._bypass_auto_encryption:
             cmd = client._encrypter.encrypt(self.db, cmd, self.codec_options)
+        # Support CSOT
+        if apply_timeout:
+            sock_info.apply_timeout(client, cmd=None)
         self._as_command = cmd, self.db
         return self._as_command
 
@@ -503,7 +515,7 @@ class _GetMore(object):
         ctx = sock_info.compression_context
 
         if use_cmd:
-            spec = self.as_command(sock_info)[0]
+            spec = self.as_command(sock_info, apply_timeout=True)[0]
             if self.sock_mgr:
                 flags = _OpMsg.EXHAUST_ALLOWED
             else:

pymongo/mongo_client.py

@@ -57,6 +57,7 @@ from bson.codec_options import DEFAULT_CODEC_OPTIONS, CodecOptions, TypeRegistry
 from bson.son import SON
 from bson.timestamp import Timestamp
 from pymongo import (
+    _csot,
     client_session,
     common,
     database,
@@ -260,6 +261,10 @@ class MongoClient(common.BaseObject, Generic[_DocumentType]):
             replaced. Defaults to `None` (no limit).
           - `maxConnecting` (optional): The maximum number of connections that
             each pool can establish concurrently. Defaults to `2`.
+          - `timeoutMS`: (integer or None) Controls how long (in
+            milliseconds) the driver will wait when executing an operation
+            (including retry attempts) before raising a timeout error.
+            ``0`` or ``None`` means no timeout.
           - `socketTimeoutMS`: (integer or None) Controls how long (in
             milliseconds) the driver will wait for a response after sending an
             ordinary (non-monitoring) database operation before concluding that
@@ -540,6 +545,9 @@ class MongoClient(common.BaseObject, Generic[_DocumentType]):
 
         .. seealso:: The MongoDB documentation on `connections <https://dochub.mongodb.org/core/connections>`_.
 
+        .. versionchanged:: 4.2
+           Added the ``timeoutMS`` keyword argument.
+
         .. versionchanged:: 4.0
 
              - Removed the fsync, unlock, is_locked, database_names, and
@@ -780,6 +788,7 @@ class MongoClient(common.BaseObject, Generic[_DocumentType]):
             options.read_preference,
             options.write_concern,
             options.read_concern,
+            options.timeout,
         )
 
         self._topology_settings = TopologySettings(
@@ -1273,6 +1282,7 @@ class MongoClient(common.BaseObject, Generic[_DocumentType]):
                     )
 
         def _cmd(session, server, sock_info, read_preference):
+            operation.reset()  # Reset op in case of retry.
             return server.run_operation(
                 sock_info, operation, read_preference, self._event_listeners, unpack_res
             )
@@ -1303,6 +1313,7 @@ class MongoClient(common.BaseObject, Generic[_DocumentType]):
         max_wire_version = 0
         last_error: Optional[Exception] = None
         retrying = False
+        multiple_retries = _csot.get_timeout() is not None
 
         def is_retrying():
             return bulk.retrying if bulk else retrying
@@ -1350,7 +1361,7 @@ class MongoClient(common.BaseObject, Generic[_DocumentType]):
                 retryable_error = exc.has_error_label("RetryableWriteError")
                 if retryable_error:
                     session._unpin()
-                if is_retrying() or not retryable_error:
+                if not retryable_error or (is_retrying() and not multiple_retries):
                     raise
                 if bulk:
                     bulk.retrying = True
@@ -1371,6 +1382,7 @@ class MongoClient(common.BaseObject, Generic[_DocumentType]):
         )
         last_error: Optional[Exception] = None
         retrying = False
+        multiple_retries = _csot.get_timeout() is not None
 
         while True:
             try:
@@ -1394,12 +1406,12 @@ class MongoClient(common.BaseObject, Generic[_DocumentType]):
                 # most likely be a waste of time.
                 raise
             except ConnectionFailure as exc:
-                if not retryable or retrying:
+                if not retryable or (retrying and not multiple_retries):
                     raise
                 retrying = True
                 last_error = exc
             except OperationFailure as exc:
-                if not retryable or retrying:
+                if not retryable or (retrying and not multiple_retries):
                     raise
                 if exc.code not in helpers._RETRYABLE_ERROR_CODES:
                     raise
@@ -1922,6 +1934,7 @@ class MongoClient(common.BaseObject, Generic[_DocumentType]):
         read_preference: Optional[_ServerMode] = None,
         write_concern: Optional[WriteConcern] = None,
         read_concern: Optional["ReadConcern"] = None,
+        timeout: Optional[float] = None,
     ) -> database.Database[_DocumentType]:
         """Get a :class:`~pymongo.database.Database` with the given name and
         options.
@@ -1972,7 +1985,7 @@ class MongoClient(common.BaseObject, Generic[_DocumentType]):
             name = self.__default_database_name
 
         return database.Database(
-            self, name, codec_options, read_preference, write_concern, read_concern
+            self, name, codec_options, read_preference, write_concern, read_concern, timeout
         )
 
     def _database_default_options(self, name):

pymongo/network.py

@@ -21,7 +21,7 @@ import struct
 import time
 
 from bson import _decode_all_selective
-from pymongo import helpers, message
+from pymongo import _csot, helpers, message, ssl_support
 from pymongo.common import MAX_MESSAGE_SIZE
 from pymongo.compression_support import _NO_COMPRESSION, decompress
 from pymongo.errors import (
@@ -59,6 +59,7 @@ def command(
     unacknowledged=False,
     user_fields=None,
     exhaust_allowed=False,
+    write_concern=None,
 ):
     """Execute a command over the socket, or raise socket.error.
 
@@ -115,6 +116,12 @@ def command(
     if client and client._encrypter and not client._encrypter._bypass_auto_encryption:
         spec = orig = client._encrypter.encrypt(dbname, spec, codec_options)
 
+    # Support CSOT
+    if client:
+        sock_info.apply_timeout(client, spec, write_concern)
+    elif write_concern and not write_concern.is_server_default:
+        spec["writeConcern"] = write_concern.document
+
     if use_op_msg:
         flags = _OpMsg.MORE_TO_COME if unacknowledged else 0
         flags |= _OpMsg.EXHAUST_ALLOWED if exhaust_allowed else 0
@@ -198,11 +205,14 @@ _UNPACK_COMPRESSION_HEADER = struct.Struct("<iiB").unpack
 
 def receive_message(sock_info, request_id, max_message_size=MAX_MESSAGE_SIZE):
     """Receive a raw BSON message or raise socket.error."""
-    timeout = sock_info.sock.gettimeout()
-    if timeout:
-        deadline = time.monotonic() + timeout
+    if _csot.get_timeout():
+        deadline = _csot.get_deadline()
     else:
-        deadline = None
+        timeout = sock_info.sock.gettimeout()
+        if timeout:
+            deadline = time.monotonic() + timeout
+        else:
+            deadline = None
     # Ignore the response's request id.
     length, _, response_to, op_code = _UNPACK_HEADER(
         _receive_data_on_socket(sock_info, 16, deadline)
@@ -271,6 +281,10 @@ def wait_for_read(sock_info, deadline):
                 raise socket.timeout("timed out")
 
 
+# Errors raised by sockets (and TLS sockets) when in non-blocking mode.
+BLOCKING_IO_ERRORS = (BlockingIOError,) + ssl_support.BLOCKING_IO_ERRORS
+
+
 def _receive_data_on_socket(sock_info, length, deadline):
     buf = bytearray(length)
     mv = memoryview(buf)
@@ -278,7 +292,14 @@ def _receive_data_on_socket(sock_info, length, deadline):
     while bytes_read < length:
         try:
             wait_for_read(sock_info, deadline)
+            # CSOT: Update timeout. When the timeout has expired perform one
+            # final non-blocking recv. This helps avoid spurious timeouts when
+            # the response is actually already buffered on the client.
+            if _csot.get_timeout():
+                sock_info.set_socket_timeout(max(deadline - time.monotonic(), 0))
             chunk_length = sock_info.sock.recv_into(mv[bytes_read:])
+        except BLOCKING_IO_ERRORS:
+            raise socket.timeout("timed out")
         except (IOError, OSError) as exc:  # noqa: B014
             if _errno_from_exception(exc) == errno.EINTR:
                 continue

pymongo/ocsp_support.py

@@ -48,6 +48,8 @@ from cryptography.x509.oid import ExtendedKeyUsageOID as _ExtendedKeyUsageOID
 from requests import post as _post
 from requests.exceptions import RequestException as _RequestException
 
+from pymongo import _csot
+
 # Note: the functions in this module generally return 1 or 0. The reason
 # is simple. The entry point, ocsp_callback, is registered as a callback
 # with OpenSSL through PyOpenSSL. The callback must return 1 (success) or
@@ -235,12 +237,16 @@ def _get_ocsp_response(cert, issuer, uri, ocsp_response_cache):
         ocsp_response = ocsp_response_cache[ocsp_request]
         _LOGGER.debug("Using cached OCSP response.")
     except KeyError:
+        # CSOT: use the configured timeout or 5 seconds, whichever is smaller.
+        # Note that request's timeout works differently and does not imply an absolute
+        # deadline: https://requests.readthedocs.io/en/stable/user/quickstart/#timeouts
+        timeout = max(_csot.clamp_remaining(5), 0.001)
         try:
             response = _post(
                 uri,
                 data=ocsp_request.public_bytes(_Encoding.DER),
                 headers={"Content-Type": "application/ocsp-request"},
-                timeout=5,
+                timeout=timeout,
             )
         except _RequestException as exc:
             _LOGGER.debug("HTTP request failed: %s", exc)

pymongo/pool.py

@@ -27,7 +27,7 @@ from typing import Any, NoReturn, Optional
 
 from bson import DEFAULT_CODEC_OPTIONS
 from bson.son import SON
-from pymongo import __version__, auth, helpers
+from pymongo import __version__, _csot, auth, helpers
 from pymongo.client_session import _validate_session_write_concern
 from pymongo.common import (
     MAX_BSON_SIZE,
@@ -46,6 +46,7 @@ from pymongo.errors import (
     ConfigurationError,
     ConnectionFailure,
     DocumentTooLarge,
+    ExecutionTimeout,
     InvalidOperation,
     NetworkTimeout,
     NotPrimaryError,
@@ -557,6 +558,43 @@ class SocketInfo(object):
         self.pinned_txn = False
         self.pinned_cursor = False
         self.active = False
+        self.last_timeout = self.opts.socket_timeout
+
+    def set_socket_timeout(self, timeout):
+        """Cache last timeout to avoid duplicate calls to sock.settimeout."""
+        if timeout == self.last_timeout:
+            return
+        self.last_timeout = timeout
+        self.sock.settimeout(timeout)
+
+    def apply_timeout(self, client, cmd, write_concern=None):
+        # CSOT: use remaining timeout when set.
+        timeout = _csot.remaining()
+        if timeout is None:
+            # Reset the socket timeout unless we're performing a streaming monitor check.
+            if not self.more_to_come:
+                self.set_socket_timeout(self.opts.socket_timeout)
+
+            if cmd and write_concern and not write_concern.is_server_default:
+                cmd["writeConcern"] = write_concern.document
+            return None
+        # RTT validation.
+        rtt = _csot.get_rtt()
+        max_time_ms = timeout - rtt
+        if max_time_ms < 0:
+            # CSOT: raise an error without running the command since we know it will time out.
+            errmsg = f"operation would exceed time limit, remaining timeout:{timeout:.5f} <= network round trip time:{rtt:.5f}"
+            raise ExecutionTimeout(
+                errmsg, 50, {"ok": 0, "errmsg": errmsg, "code": 50}, self.max_wire_version
+            )
+        if cmd is not None:
+            cmd["maxTimeMS"] = int(max_time_ms * 1000)
+            wc = write_concern.document if write_concern else {}
+            wc.pop("wtimeout", None)
+            if wc:
+                cmd["writeConcern"] = wc
+        self.set_socket_timeout(timeout)
+        return timeout
 
     def pin_txn(self):
         self.pinned_txn = True
@@ -602,7 +640,7 @@ class SocketInfo(object):
             awaitable = True
             # If connect_timeout is None there is no timeout.
             if self.opts.connect_timeout:
-                self.sock.settimeout(self.opts.connect_timeout + heartbeat_frequency)
+                self.set_socket_timeout(self.opts.connect_timeout + heartbeat_frequency)
 
         if not performing_handshake and cluster_time is not None:
             cmd["$clusterTime"] = cluster_time
@@ -714,8 +752,6 @@ class SocketInfo(object):
 
         if not (write_concern is None or write_concern.acknowledged or collation is None):
             raise ConfigurationError("Collation is unsupported for unacknowledged writes.")
-        if write_concern and not write_concern.is_server_default:
-            spec["writeConcern"] = write_concern.document
 
         self.add_server_api(spec)
         if session:
@@ -748,6 +784,7 @@ class SocketInfo(object):
                 unacknowledged=unacknowledged,
                 user_fields=user_fields,
                 exhaust_allowed=exhaust_allowed,
+                write_concern=write_concern,
             )
         except (OperationFailure, NotPrimaryError):
             raise
@@ -978,7 +1015,13 @@ def _create_connection(address, options):
         _set_non_inheritable_non_atomic(sock.fileno())
         try:
             sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
-            sock.settimeout(options.connect_timeout)
+            # CSOT: apply timeout to socket connect.
+            timeout = _csot.remaining()
+            if timeout is None:
+                timeout = options.connect_timeout
+            elif timeout <= 0:
+                raise socket.timeout("timed out")
+            sock.settimeout(timeout)
             sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, True)
             _set_keepalive_times(sock)
             sock.connect(sa)
@@ -1416,7 +1459,9 @@ class Pool:
             self.operation_count += 1
 
         # Get a free socket or create one.
-        if self.opts.wait_queue_timeout:
+        if _csot.get_timeout():
+            deadline = _csot.get_deadline()
+        elif self.opts.wait_queue_timeout:
             deadline = time.monotonic() + self.opts.wait_queue_timeout
         else:
             deadline = None
@@ -1582,25 +1627,25 @@ class Pool:
             listeners.publish_connection_check_out_failed(
                 self.address, ConnectionCheckOutFailedReason.TIMEOUT
             )
+        timeout = _csot.get_timeout() or self.opts.wait_queue_timeout
         if self.opts.load_balanced:
             other_ops = self.active_sockets - self.ncursors - self.ntxns
             raise ConnectionFailure(
                 "Timeout waiting for connection from the connection pool. "
                 "maxPoolSize: %s, connections in use by cursors: %s, "
                 "connections in use by transactions: %s, connections in use "
-                "by other operations: %s, wait_queue_timeout: %s"
+                "by other operations: %s, timeout: %s"
                 % (
                     self.opts.max_pool_size,
                     self.ncursors,
                     self.ntxns,
                     other_ops,
-                    self.opts.wait_queue_timeout,
+                    timeout,
                 )
             )
         raise ConnectionFailure(
             "Timed out while checking out a connection from connection pool. "
-            "maxPoolSize: %s, wait_queue_timeout: %s"
-            % (self.opts.max_pool_size, self.opts.wait_queue_timeout)
+            "maxPoolSize: %s, timeout: %s" % (self.opts.max_pool_size, timeout)
         )
 
     def __del__(self):

pymongo/pyopenssl_context.py

@@ -82,7 +82,7 @@ def _is_ip_address(address):
 
 # According to the docs for Connection.send it can raise
 # WantX509LookupError and should be retried.
-_RETRY_ERRORS = (_SSL.WantReadError, _SSL.WantWriteError, _SSL.WantX509LookupError)
+BLOCKING_IO_ERRORS = (_SSL.WantReadError, _SSL.WantWriteError, _SSL.WantX509LookupError)
 
 
 def _ragged_eof(exc):
@@ -106,7 +106,7 @@ class _sslConn(_SSL.Connection):
         while True:
             try:
                 return call(*args, **kwargs)
-            except _RETRY_ERRORS as exc:
+            except BLOCKING_IO_ERRORS as exc:
                 if isinstance(exc, _SSL.WantReadError):
                     want_read = True
                     want_write = False

pymongo/ssl_context.py

@@ -27,6 +27,9 @@ OP_NO_RENEGOTIATION = getattr(_ssl, "OP_NO_RENEGOTIATION", 0)
 HAS_SNI = getattr(_ssl, "HAS_SNI", False)
 IS_PYOPENSSL = False
 
+# Errors raised by SSL sockets when in non-blocking mode.
+BLOCKING_IO_ERRORS = (_ssl.SSLWantReadError, _ssl.SSLWantWriteError)
+
 # Base Exception class
 SSLError = _ssl.SSLError
 

pymongo/ssl_support.py

@@ -38,6 +38,7 @@ if HAVE_SSL:
     HAS_SNI = _ssl.HAS_SNI
     IPADDR_SAFE = True
     SSLError = _ssl.SSLError
+    BLOCKING_IO_ERRORS = _ssl.BLOCKING_IO_ERRORS
 
     def get_ssl_context(
         certfile,
@@ -91,6 +92,7 @@ else:
 
     HAS_SNI = False
     IPADDR_SAFE = False
+    BLOCKING_IO_ERRORS = ()  # type: ignore
 
     def get_ssl_context(*dummy):  # type: ignore
         """No ssl module, raise ConfigurationError."""

pymongo/topology.py

@@ -23,7 +23,7 @@ import warnings
 import weakref
 from typing import Any
 
-from pymongo import common, helpers, periodic_executor
+from pymongo import _csot, common, helpers, periodic_executor
 from pymongo.client_session import _ServerSessionPool
 from pymongo.errors import (
     ConfigurationError,
@@ -191,6 +191,13 @@ class Topology(object):
         with self._lock:
             self._ensure_opened()
 
+    def get_server_selection_timeout(self):
+        # CSOT: use remaining timeout when set.
+        timeout = _csot.remaining()
+        if timeout is None:
+            return self._settings.server_selection_timeout
+        return timeout
+
     def select_servers(self, selector, server_selection_timeout=None, address=None):
         """Return a list of Servers matching selector, or time out.
 
@@ -208,7 +215,7 @@ class Topology(object):
         `server_selection_timeout` if no matching servers are found.
         """
         if server_selection_timeout is None:
-            server_timeout = self._settings.server_selection_timeout
+            server_timeout = self.get_server_selection_timeout()
         else:
             server_timeout = server_selection_timeout
 
@@ -250,8 +257,7 @@ class Topology(object):
         self._description.check_compatible()
         return server_descriptions
 
-    def select_server(self, selector, server_selection_timeout=None, address=None):
-        """Like select_servers, but choose a random server if several match."""
+    def _select_server(self, selector, server_selection_timeout=None, address=None):
         servers = self.select_servers(selector, server_selection_timeout, address)
         if len(servers) == 1:
             return servers[0]
@@ -261,6 +267,12 @@ class Topology(object):
         else:
             return server2
 
+    def select_server(self, selector, server_selection_timeout=None, address=None):
+        """Like select_servers, but choose a random server if several match."""
+        server = self._select_server(selector, server_selection_timeout, address)
+        _csot.set_rtt(server.description.round_trip_time)
+        return server
+
     def select_server_by_address(self, address, server_selection_timeout=None):
         """Return a Server for "address", reconnecting if necessary.
 
@@ -535,11 +547,11 @@ class Topology(object):
             if self._description.topology_type == TOPOLOGY_TYPE.Single:
                 if not self._description.has_known_servers:
                     self._select_servers_loop(
-                        any_server_selector, self._settings.server_selection_timeout, None
+                        any_server_selector, self.get_server_selection_timeout(), None
                     )
             elif not self._description.readable_servers:
                 self._select_servers_loop(
-                    readable_server_selector, self._settings.server_selection_timeout, None
+                    readable_server_selector, self.get_server_selection_timeout(), None
                 )
 
             session_timeout = self._description.logical_session_timeout_minutes

test/csot/bulkWrite.json

@@ -0,0 +1,159 @@
+{
+  "description": "timeoutMS behaves correctly for bulkWrite operations",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection",
+        "database": "database",
+        "collectionName": "coll"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll",
+      "databaseName": "test",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "timeoutMS applied to entire bulkWrite, not individual commands",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "insert",
+                  "update"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 120
+              }
+            }
+          }
+        },
+        {
+          "name": "find",
+          "object": "collection",
+          "arguments": {
+            "filter": {
+              "_id": 1
+            }
+          }
+        },
+        {
+          "name": "bulkWrite",
+          "object": "collection",
+          "arguments": {
+            "requests": [
+              {
+                "insertOne": {
+                  "document": {
+                    "_id": 1
+                  }
+                }
+              },
+              {
+                "replaceOne": {
+                  "filter": {
+                    "_id": 1
+                  },
+                  "replacement": {
+                    "x": 1
+                  }
+                }
+              }
+            ],
+            "timeoutMS": 200
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "coll"
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "update",
+                "databaseName": "test",
+                "command": {
+                  "update": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/csot/change-streams.json

@@ -0,0 +1,598 @@
+{
+  "description": "timeoutMS behaves correctly for change streams",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4",
+      "topologies": [
+        "replicaset",
+        "sharded-replicaset"
+      ]
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent"
+        ],
+        "ignoreCommandMonitoringEvents": [
+          "killCursors"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection",
+        "database": "database",
+        "collectionName": "coll"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll",
+      "databaseName": "test",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "error if maxAwaitTimeMS is greater than timeoutMS",
+      "operations": [
+        {
+          "name": "createChangeStream",
+          "object": "collection",
+          "arguments": {
+            "pipeline": [],
+            "timeoutMS": 5,
+            "maxAwaitTimeMS": 10
+          },
+          "expectError": {
+            "isClientError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "error if maxAwaitTimeMS is equal to timeoutMS",
+      "operations": [
+        {
+          "name": "createChangeStream",
+          "object": "collection",
+          "arguments": {
+            "pipeline": [],
+            "timeoutMS": 5,
+            "maxAwaitTimeMS": 5
+          },
+          "expectError": {
+            "isClientError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to initial aggregate",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "aggregate"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "createChangeStream",
+          "object": "collection",
+          "arguments": {
+            "pipeline": [],
+            "timeoutMS": 50
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "aggregate",
+                "databaseName": "test",
+                "command": {
+                  "aggregate": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS is refreshed for getMore if maxAwaitTimeMS is not set",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "aggregate",
+                  "getMore"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 30
+              }
+            }
+          }
+        },
+        {
+          "name": "createChangeStream",
+          "object": "collection",
+          "arguments": {
+            "pipeline": [],
+            "timeoutMS": 1050
+          },
+          "saveResultAsEntity": "changeStream"
+        },
+        {
+          "name": "iterateOnce",
+          "object": "changeStream"
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "aggregate",
+                "databaseName": "test",
+                "command": {
+                  "aggregate": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS is refreshed for getMore if maxAwaitTimeMS is set",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "aggregate",
+                  "getMore"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "createChangeStream",
+          "object": "collection",
+          "arguments": {
+            "pipeline": [],
+            "timeoutMS": 20,
+            "batchSize": 2,
+            "maxAwaitTimeMS": 1
+          },
+          "saveResultAsEntity": "changeStream"
+        },
+        {
+          "name": "iterateOnce",
+          "object": "changeStream"
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "aggregate",
+                "databaseName": "test",
+                "command": {
+                  "aggregate": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll",
+                  "maxTimeMS": 1
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applies to full resume attempt in a next call",
+      "operations": [
+        {
+          "name": "createChangeStream",
+          "object": "collection",
+          "arguments": {
+            "pipeline": [],
+            "timeoutMS": 20
+          },
+          "saveResultAsEntity": "changeStream"
+        },
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "getMore",
+                  "aggregate"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 12,
+                "errorCode": 7,
+                "errorLabels": [
+                  "ResumableChangeStreamError"
+                ]
+              }
+            }
+          }
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "changeStream",
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "aggregate",
+                "databaseName": "test",
+                "command": {
+                  "aggregate": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "aggregate",
+                "databaseName": "test",
+                "command": {
+                  "aggregate": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "change stream can be iterated again if previous iteration times out",
+      "operations": [
+        {
+          "name": "createChangeStream",
+          "object": "collection",
+          "arguments": {
+            "pipeline": [],
+            "maxAwaitTimeMS": 1,
+            "timeoutMS": 100
+          },
+          "saveResultAsEntity": "changeStream"
+        },
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "getMore"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 150
+              }
+            }
+          }
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "changeStream",
+          "expectError": {
+            "isTimeoutError": true
+          }
+        },
+        {
+          "name": "iterateOnce",
+          "object": "changeStream"
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "aggregate",
+                "databaseName": "test",
+                "command": {
+                  "aggregate": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll"
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "aggregate",
+                "databaseName": "test",
+                "command": {
+                  "aggregate": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll"
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS is refreshed for getMore - failure",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "getMore"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "createChangeStream",
+          "object": "collection",
+          "arguments": {
+            "pipeline": [],
+            "timeoutMS": 10
+          },
+          "saveResultAsEntity": "changeStream"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "changeStream",
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "aggregate",
+                "databaseName": "test",
+                "command": {
+                  "aggregate": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll"
+                }
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/csot/close-cursors.json

@@ -0,0 +1,239 @@
+{
+  "description": "timeoutMS behaves correctly when closing cursors",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent",
+          "commandSucceededEvent",
+          "commandFailedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection",
+        "database": "database",
+        "collectionName": "coll"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll",
+      "databaseName": "test",
+      "documents": [
+        {
+          "_id": 0
+        },
+        {
+          "_id": 1
+        },
+        {
+          "_id": 2
+        }
+      ]
+    }
+  ],
+  "tests": [
+    {
+      "description": "timeoutMS is refreshed for close",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "getMore"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 50
+              }
+            }
+          }
+        },
+        {
+          "name": "createFindCursor",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "batchSize": 2,
+            "timeoutMS": 20
+          },
+          "saveResultAsEntity": "cursor"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "cursor"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "cursor"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "cursor",
+          "expectError": {
+            "isTimeoutError": true
+          }
+        },
+        {
+          "name": "close",
+          "object": "cursor"
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find"
+              }
+            },
+            {
+              "commandSucceededEvent": {
+                "commandName": "find"
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore"
+              }
+            },
+            {
+              "commandFailedEvent": {
+                "commandName": "getMore"
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "command": {
+                  "killCursors": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                },
+                "commandName": "killCursors"
+              }
+            },
+            {
+              "commandSucceededEvent": {
+                "commandName": "killCursors"
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS can be overridden for close",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "client",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "killCursors"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 30
+              }
+            }
+          }
+        },
+        {
+          "name": "createFindCursor",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "batchSize": 2,
+            "timeoutMS": 20
+          },
+          "saveResultAsEntity": "cursor"
+        },
+        {
+          "name": "close",
+          "object": "cursor",
+          "arguments": {
+            "timeoutMS": 40
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find"
+              }
+            },
+            {
+              "commandSucceededEvent": {
+                "commandName": "find"
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "command": {
+                  "killCursors": "collection",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                },
+                "commandName": "killCursors"
+              }
+            },
+            {
+              "commandSucceededEvent": {
+                "commandName": "killCursors"
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/csot/command-execution.json

@@ -0,0 +1,260 @@
+{
+  "description": "timeoutMS behaves correctly during command execution",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.9"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll",
+      "databaseName": "test",
+      "documents": []
+    },
+    {
+      "collectionName": "timeoutColl",
+      "databaseName": "test",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "maxTimeMS value in the command is less than timeoutMS",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": "alwaysOn",
+              "data": {
+                "failCommands": [
+                  "hello",
+                  "isMaster"
+                ],
+                "appName": "reduceMaxTimeMSTest",
+                "blockConnection": true,
+                "blockTimeMS": 20
+              }
+            }
+          }
+        },
+        {
+          "name": "createEntities",
+          "object": "testRunner",
+          "arguments": {
+            "entities": [
+              {
+                "client": {
+                  "id": "client",
+                  "useMultipleMongoses": false,
+                  "uriOptions": {
+                    "appName": "reduceMaxTimeMSTest",
+                    "w": 1
+                  },
+                  "observeEvents": [
+                    "commandStartedEvent"
+                  ]
+                }
+              },
+              {
+                "database": {
+                  "id": "database",
+                  "client": "client",
+                  "databaseName": "test"
+                }
+              },
+              {
+                "collection": {
+                  "id": "regularCollection",
+                  "database": "database",
+                  "collectionName": "coll"
+                }
+              },
+              {
+                "collection": {
+                  "id": "timeoutCollection",
+                  "database": "database",
+                  "collectionName": "timeoutColl",
+                  "collectionOptions": {
+                    "timeoutMS": 60
+                  }
+                }
+              }
+            ]
+          }
+        },
+        {
+          "name": "insertOne",
+          "object": "regularCollection",
+          "arguments": {
+            "document": {
+              "_id": 1
+            }
+          }
+        },
+        {
+          "name": "insertOne",
+          "object": "timeoutCollection",
+          "arguments": {
+            "document": {
+              "_id": 2
+            }
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "timeoutColl",
+                  "maxTimeMS": {
+                    "$$lte": 60
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "command is not sent if RTT is greater than timeoutMS",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": "alwaysOn",
+              "data": {
+                "failCommands": [
+                  "hello",
+                  "isMaster"
+                ],
+                "appName": "rttTooHighTest",
+                "blockConnection": true,
+                "blockTimeMS": 20
+              }
+            }
+          }
+        },
+        {
+          "name": "createEntities",
+          "object": "testRunner",
+          "arguments": {
+            "entities": [
+              {
+                "client": {
+                  "id": "client",
+                  "useMultipleMongoses": false,
+                  "uriOptions": {
+                    "appName": "rttTooHighTest",
+                    "w": 1
+                  },
+                  "observeEvents": [
+                    "commandStartedEvent"
+                  ]
+                }
+              },
+              {
+                "database": {
+                  "id": "database",
+                  "client": "client",
+                  "databaseName": "test"
+                }
+              },
+              {
+                "collection": {
+                  "id": "regularCollection",
+                  "database": "database",
+                  "collectionName": "coll"
+                }
+              },
+              {
+                "collection": {
+                  "id": "timeoutCollection",
+                  "database": "database",
+                  "collectionName": "timeoutColl",
+                  "collectionOptions": {
+                    "timeoutMS": 2
+                  }
+                }
+              }
+            ]
+          }
+        },
+        {
+          "name": "insertOne",
+          "object": "regularCollection",
+          "arguments": {
+            "document": {
+              "_id": 1
+            }
+          }
+        },
+        {
+          "name": "insertOne",
+          "object": "timeoutCollection",
+          "arguments": {
+            "document": {
+              "_id": 2
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/csot/convenient-transactions.json

@@ -0,0 +1,191 @@
+{
+  "description": "timeoutMS behaves correctly for the withTransaction API",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4",
+      "topologies": [
+        "replicaset",
+        "sharded-replicaset"
+      ]
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "uriOptions": {
+          "timeoutMS": 50
+        },
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection",
+        "database": "database",
+        "collectionName": "coll"
+      }
+    },
+    {
+      "session": {
+        "id": "session",
+        "client": "client"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll",
+      "databaseName": "test",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "withTransaction raises a client-side error if timeoutMS is overridden inside the callback",
+      "operations": [
+        {
+          "name": "withTransaction",
+          "object": "session",
+          "arguments": {
+            "callback": [
+              {
+                "name": "insertOne",
+                "object": "collection",
+                "arguments": {
+                  "document": {
+                    "_id": 1
+                  },
+                  "session": "session",
+                  "timeoutMS": 100
+                },
+                "expectError": {
+                  "isClientError": true
+                }
+              }
+            ]
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": []
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS is not refreshed for each operation in the callback",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "insert"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 30
+              }
+            }
+          }
+        },
+        {
+          "name": "withTransaction",
+          "object": "session",
+          "arguments": {
+            "callback": [
+              {
+                "name": "insertOne",
+                "object": "collection",
+                "arguments": {
+                  "document": {
+                    "_id": 1
+                  },
+                  "session": "session"
+                }
+              },
+              {
+                "name": "insertOne",
+                "object": "collection",
+                "arguments": {
+                  "document": {
+                    "_id": 2
+                  },
+                  "session": "session"
+                },
+                "expectError": {
+                  "isTimeoutError": true
+                }
+              }
+            ]
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/csot/cursors.json

@@ -0,0 +1,113 @@
+{
+  "description": "tests for timeoutMS behavior that applies to all cursor types",
+  "schemaVersion": "1.0",
+  "createEntities": [
+    {
+      "client": {
+        "id": "client"
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection",
+        "database": "database",
+        "collectionName": "coll"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll",
+      "databaseName": "test",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "find errors if timeoutMode is set and timeoutMS is not",
+      "operations": [
+        {
+          "name": "find",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "timeoutMode": "cursorLifetime"
+          },
+          "expectError": {
+            "isClientError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "collection aggregate errors if timeoutMode is set and timeoutMS is not",
+      "operations": [
+        {
+          "name": "aggregate",
+          "object": "collection",
+          "arguments": {
+            "pipeline": [],
+            "timeoutMode": "cursorLifetime"
+          },
+          "expectError": {
+            "isClientError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "database aggregate errors if timeoutMode is set and timeoutMS is not",
+      "operations": [
+        {
+          "name": "aggregate",
+          "object": "database",
+          "arguments": {
+            "pipeline": [],
+            "timeoutMode": "cursorLifetime"
+          },
+          "expectError": {
+            "isClientError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "listCollections errors if timeoutMode is set and timeoutMS is not",
+      "operations": [
+        {
+          "name": "listCollections",
+          "object": "database",
+          "arguments": {
+            "filter": {},
+            "timeoutMode": "cursorLifetime"
+          },
+          "expectError": {
+            "isClientError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "listIndexes errors if timeoutMode is set and timeoutMS is not",
+      "operations": [
+        {
+          "name": "listIndexes",
+          "object": "collection",
+          "arguments": {
+            "timeoutMode": "cursorLifetime"
+          },
+          "expectError": {
+            "isClientError": true
+          }
+        }
+      ]
+    }
+  ]
+}

test/csot/error-transformations.json

@@ -0,0 +1,181 @@
+{
+  "description": "MaxTimeMSExpired server errors are transformed into a custom timeout error",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.0",
+      "topologies": [
+        "replicaset"
+      ]
+    },
+    {
+      "minServerVersion": "4.2",
+      "topologies": [
+        "replicaset",
+        "sharded"
+      ]
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "uriOptions": {
+          "timeoutMS": 250
+        },
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection",
+        "database": "database",
+        "collectionName": "coll"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll",
+      "databaseName": "test",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "basic MaxTimeMSExpired error is transformed",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "insert"
+                ],
+                "errorCode": 50
+              }
+            }
+          }
+        },
+        {
+          "name": "insertOne",
+          "object": "collection",
+          "arguments": {
+            "document": {
+              "_id": 1
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "write concern error MaxTimeMSExpired is transformed",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "insert"
+                ],
+                "writeConcernError": {
+                  "code": 50,
+                  "errmsg": "maxTimeMS expired"
+                }
+              }
+            }
+          }
+        },
+        {
+          "name": "insertOne",
+          "object": "collection",
+          "arguments": {
+            "document": {
+              "_id": 1
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/csot/gridfs-advanced.json

@@ -0,0 +1,370 @@
+{
+  "description": "timeoutMS behaves correctly for advanced GridFS API operations",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "uriOptions": {
+          "timeoutMS": 50
+        },
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "bucket": {
+        "id": "bucket",
+        "database": "database"
+      }
+    },
+    {
+      "collection": {
+        "id": "filesCollection",
+        "database": "database",
+        "collectionName": "fs.files"
+      }
+    },
+    {
+      "collection": {
+        "id": "chunksCollection",
+        "database": "database",
+        "collectionName": "fs.chunks"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "fs.files",
+      "databaseName": "test",
+      "documents": [
+        {
+          "_id": {
+            "$oid": "000000000000000000000005"
+          },
+          "length": 10,
+          "chunkSize": 4,
+          "uploadDate": {
+            "$date": "1970-01-01T00:00:00.000Z"
+          },
+          "md5": "57d83cd477bfb1ccd975ab33d827a92b",
+          "filename": "length-10",
+          "contentType": "application/octet-stream",
+          "aliases": [],
+          "metadata": {}
+        }
+      ]
+    },
+    {
+      "collectionName": "fs.chunks",
+      "databaseName": "test",
+      "documents": [
+        {
+          "_id": {
+            "$oid": "000000000000000000000005"
+          },
+          "files_id": {
+            "$oid": "000000000000000000000005"
+          },
+          "n": 0,
+          "data": {
+            "$binary": {
+              "base64": "ESIzRA==",
+              "subType": "00"
+            }
+          }
+        }
+      ]
+    }
+  ],
+  "tests": [
+    {
+      "description": "timeoutMS can be overridden for a rename",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "update"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "rename",
+          "object": "bucket",
+          "arguments": {
+            "id": {
+              "$oid": "000000000000000000000005"
+            },
+            "newFilename": "foo",
+            "timeoutMS": 100
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "update",
+                "databaseName": "test",
+                "command": {
+                  "update": "fs.files",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to update during a rename",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "update"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "rename",
+          "object": "bucket",
+          "arguments": {
+            "id": {
+              "$oid": "000000000000000000000005"
+            },
+            "newFilename": "foo"
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "update",
+                "databaseName": "test",
+                "command": {
+                  "update": "fs.files",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS can be overridden for drop",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "drop"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "drop",
+          "object": "bucket",
+          "arguments": {
+            "timeoutMS": 100
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to files collection drop",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "drop"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "drop",
+          "object": "bucket",
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "drop",
+                "databaseName": "test",
+                "command": {
+                  "drop": "fs.files",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to chunks collection drop",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "skip": 1
+              },
+              "data": {
+                "failCommands": [
+                  "drop"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "drop",
+          "object": "bucket",
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to drop as a whole, not individual parts",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "drop"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 30
+              }
+            }
+          }
+        },
+        {
+          "name": "drop",
+          "object": "bucket",
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ]
+    }
+  ]
+}

test/csot/gridfs-delete.json

@@ -0,0 +1,270 @@
+{
+  "description": "timeoutMS behaves correctly for GridFS delete operations",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "uriOptions": {
+          "timeoutMS": 50
+        },
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "bucket": {
+        "id": "bucket",
+        "database": "database"
+      }
+    },
+    {
+      "collection": {
+        "id": "filesCollection",
+        "database": "database",
+        "collectionName": "fs.files"
+      }
+    },
+    {
+      "collection": {
+        "id": "chunksCollection",
+        "database": "database",
+        "collectionName": "fs.chunks"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "fs.files",
+      "databaseName": "test",
+      "documents": [
+        {
+          "_id": {
+            "$oid": "000000000000000000000005"
+          },
+          "length": 10,
+          "chunkSize": 4,
+          "uploadDate": {
+            "$date": "1970-01-01T00:00:00.000Z"
+          },
+          "md5": "57d83cd477bfb1ccd975ab33d827a92b",
+          "filename": "length-10",
+          "contentType": "application/octet-stream",
+          "aliases": [],
+          "metadata": {}
+        }
+      ]
+    },
+    {
+      "collectionName": "fs.chunks",
+      "databaseName": "test",
+      "documents": [
+        {
+          "_id": {
+            "$oid": "000000000000000000000005"
+          },
+          "files_id": {
+            "$oid": "000000000000000000000005"
+          },
+          "n": 0,
+          "data": {
+            "$binary": {
+              "base64": "ESIzRA==",
+              "subType": "00"
+            }
+          }
+        }
+      ]
+    }
+  ],
+  "tests": [
+    {
+      "description": "timeoutMS can be overridden for delete",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "delete"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "delete",
+          "object": "bucket",
+          "arguments": {
+            "id": {
+              "$oid": "000000000000000000000005"
+            },
+            "timeoutMS": 100
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to delete against the files collection",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "delete"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "delete",
+          "object": "bucket",
+          "arguments": {
+            "id": {
+              "$oid": "000000000000000000000005"
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "delete",
+                "databaseName": "test",
+                "command": {
+                  "delete": "fs.files",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to delete against the chunks collection",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "skip": 1
+              },
+              "data": {
+                "failCommands": [
+                  "delete"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "delete",
+          "object": "bucket",
+          "arguments": {
+            "id": {
+              "$oid": "000000000000000000000005"
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to entire delete, not individual parts",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "delete"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 30
+              }
+            }
+          }
+        },
+        {
+          "name": "delete",
+          "object": "bucket",
+          "arguments": {
+            "id": {
+              "$oid": "000000000000000000000005"
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ]
+    }
+  ]
+}

test/csot/gridfs-download.json

@@ -0,0 +1,344 @@
+{
+  "description": "timeoutMS behaves correctly for GridFS download operations",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "uriOptions": {
+          "timeoutMS": 50
+        },
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "bucket": {
+        "id": "bucket",
+        "database": "database"
+      }
+    },
+    {
+      "collection": {
+        "id": "filesCollection",
+        "database": "database",
+        "collectionName": "fs.files"
+      }
+    },
+    {
+      "collection": {
+        "id": "chunksCollection",
+        "database": "database",
+        "collectionName": "fs.chunks"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "fs.files",
+      "databaseName": "test",
+      "documents": [
+        {
+          "_id": {
+            "$oid": "000000000000000000000005"
+          },
+          "length": 10,
+          "chunkSize": 4,
+          "uploadDate": {
+            "$date": "1970-01-01T00:00:00.000Z"
+          },
+          "md5": "57d83cd477bfb1ccd975ab33d827a92b",
+          "filename": "length-10",
+          "contentType": "application/octet-stream",
+          "aliases": [],
+          "metadata": {}
+        }
+      ]
+    },
+    {
+      "collectionName": "fs.chunks",
+      "databaseName": "test",
+      "documents": [
+        {
+          "_id": {
+            "$oid": "000000000000000000000005"
+          },
+          "files_id": {
+            "$oid": "000000000000000000000005"
+          },
+          "n": 0,
+          "data": {
+            "$binary": {
+              "base64": "ESIzRA==",
+              "subType": "00"
+            }
+          }
+        }
+      ]
+    }
+  ],
+  "tests": [
+    {
+      "description": "timeoutMS can be overridden for download",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "find"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "download",
+          "object": "bucket",
+          "arguments": {
+            "id": {
+              "$oid": "000000000000000000000005"
+            },
+            "timeoutMS": 100
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to find to get files document",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "find"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "download",
+          "object": "bucket",
+          "arguments": {
+            "id": {
+              "$oid": "000000000000000000000005"
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "fs.files",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to find to get chunks",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "skip": 1
+              },
+              "data": {
+                "failCommands": [
+                  "find"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "download",
+          "object": "bucket",
+          "arguments": {
+            "id": {
+              "$oid": "000000000000000000000005"
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "fs.files",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "fs.chunks",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to entire download, not individual parts",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "find"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 30
+              }
+            }
+          }
+        },
+        {
+          "name": "download",
+          "object": "bucket",
+          "arguments": {
+            "id": {
+              "$oid": "000000000000000000000005"
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "fs.files",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "fs.chunks",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/csot/gridfs-find.json

@@ -0,0 +1,182 @@
+{
+  "description": "timeoutMS behaves correctly for GridFS find operations",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "uriOptions": {
+          "timeoutMS": 50
+        },
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "bucket": {
+        "id": "bucket",
+        "database": "database"
+      }
+    },
+    {
+      "collection": {
+        "id": "filesCollection",
+        "database": "database",
+        "collectionName": "fs.files"
+      }
+    },
+    {
+      "collection": {
+        "id": "chunksCollection",
+        "database": "database",
+        "collectionName": "fs.chunks"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "fs.files",
+      "databaseName": "test",
+      "documents": []
+    },
+    {
+      "collectionName": "fs.chunks",
+      "databaseName": "test",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "timeoutMS can be overridden for a find",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "find"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "find",
+          "object": "bucket",
+          "arguments": {
+            "filter": {},
+            "timeoutMS": 100
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "fs.files",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to find command",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "find"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "find",
+          "object": "bucket",
+          "arguments": {
+            "filter": {}
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "fs.files",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/csot/gridfs-upload.json

@@ -0,0 +1,408 @@
+{
+  "description": "timeoutMS behaves correctly for GridFS upload operations",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "uriOptions": {
+          "timeoutMS": 50
+        },
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "bucket": {
+        "id": "bucket",
+        "database": "database"
+      }
+    },
+    {
+      "collection": {
+        "id": "filesCollection",
+        "database": "database",
+        "collectionName": "fs.files"
+      }
+    },
+    {
+      "collection": {
+        "id": "chunksCollection",
+        "database": "database",
+        "collectionName": "fs.chunks"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "fs.files",
+      "databaseName": "test",
+      "documents": []
+    },
+    {
+      "collectionName": "fs.chunks",
+      "databaseName": "test",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "timeoutMS can be overridden for upload",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "find"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "upload",
+          "object": "bucket",
+          "arguments": {
+            "filename": "filename",
+            "source": {
+              "$$hexBytes": "1122334455"
+            },
+            "timeoutMS": 1000
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to initial find on files collection",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "find"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "upload",
+          "object": "bucket",
+          "arguments": {
+            "filename": "filename",
+            "source": {
+              "$$hexBytes": "1122334455"
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to listIndexes on files collection",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "listIndexes"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "upload",
+          "object": "bucket",
+          "arguments": {
+            "filename": "filename",
+            "source": {
+              "$$hexBytes": "1122334455"
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to index creation for files collection",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "createIndexes"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "upload",
+          "object": "bucket",
+          "arguments": {
+            "filename": "filename",
+            "source": {
+              "$$hexBytes": "1122334455"
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to listIndexes on chunks collection",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "skip": 1
+              },
+              "data": {
+                "failCommands": [
+                  "listIndexes"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "upload",
+          "object": "bucket",
+          "arguments": {
+            "filename": "filename",
+            "source": {
+              "$$hexBytes": "1122334455"
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to index creation for chunks collection",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "skip": 1
+              },
+              "data": {
+                "failCommands": [
+                  "createIndexes"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "upload",
+          "object": "bucket",
+          "arguments": {
+            "filename": "filename",
+            "source": {
+              "$$hexBytes": "1122334455"
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to chunk insertion",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "insert"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "upload",
+          "object": "bucket",
+          "arguments": {
+            "filename": "filename",
+            "source": {
+              "$$hexBytes": "1122334455"
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to creation of files document",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "skip": 1
+              },
+              "data": {
+                "failCommands": [
+                  "insert"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 55
+              }
+            }
+          }
+        },
+        {
+          "name": "upload",
+          "object": "bucket",
+          "arguments": {
+            "filename": "filename",
+            "source": {
+              "$$hexBytes": "1122334455"
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to upload as a whole, not individual parts",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "find",
+                  "listIndexes"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 30
+              }
+            }
+          }
+        },
+        {
+          "name": "upload",
+          "object": "bucket",
+          "arguments": {
+            "filename": "filename",
+            "source": {
+              "$$hexBytes": "1122334455"
+            }
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ]
+    }
+  ]
+}

test/csot/legacy-timeouts.json

@@ -0,0 +1,379 @@
+{
+  "description": "legacy timeouts continue to work if timeoutMS is not set",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4"
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll",
+      "databaseName": "test",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "socketTimeoutMS is not used to derive a maxTimeMS command field",
+      "operations": [
+        {
+          "name": "createEntities",
+          "object": "testRunner",
+          "arguments": {
+            "entities": [
+              {
+                "client": {
+                  "id": "client",
+                  "observeEvents": [
+                    "commandStartedEvent"
+                  ],
+                  "uriOptions": {
+                    "socketTimeoutMS": 50000
+                  }
+                }
+              },
+              {
+                "database": {
+                  "id": "database",
+                  "client": "client",
+                  "databaseName": "test"
+                }
+              },
+              {
+                "collection": {
+                  "id": "collection",
+                  "database": "database",
+                  "collectionName": "coll"
+                }
+              }
+            ]
+          }
+        },
+        {
+          "name": "insertOne",
+          "object": "collection",
+          "arguments": {
+            "document": {
+              "x": 1
+            }
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "waitQueueTimeoutMS is not used to derive a maxTimeMS command field",
+      "operations": [
+        {
+          "name": "createEntities",
+          "object": "testRunner",
+          "arguments": {
+            "entities": [
+              {
+                "client": {
+                  "id": "client",
+                  "observeEvents": [
+                    "commandStartedEvent"
+                  ],
+                  "uriOptions": {
+                    "waitQueueTimeoutMS": 50000
+                  }
+                }
+              },
+              {
+                "database": {
+                  "id": "database",
+                  "client": "client",
+                  "databaseName": "test"
+                }
+              },
+              {
+                "collection": {
+                  "id": "collection",
+                  "database": "database",
+                  "collectionName": "coll"
+                }
+              }
+            ]
+          }
+        },
+        {
+          "name": "insertOne",
+          "object": "collection",
+          "arguments": {
+            "document": {
+              "x": 1
+            }
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "wTimeoutMS is not used to derive a maxTimeMS command field",
+      "operations": [
+        {
+          "name": "createEntities",
+          "object": "testRunner",
+          "arguments": {
+            "entities": [
+              {
+                "client": {
+                  "id": "client",
+                  "observeEvents": [
+                    "commandStartedEvent"
+                  ],
+                  "uriOptions": {
+                    "wTimeoutMS": 50000
+                  }
+                }
+              },
+              {
+                "database": {
+                  "id": "database",
+                  "client": "client",
+                  "databaseName": "test"
+                }
+              },
+              {
+                "collection": {
+                  "id": "collection",
+                  "database": "database",
+                  "collectionName": "coll"
+                }
+              }
+            ]
+          }
+        },
+        {
+          "name": "insertOne",
+          "object": "collection",
+          "arguments": {
+            "document": {
+              "x": 1
+            }
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  },
+                  "writeConcern": {
+                    "wtimeout": 50000
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "maxTimeMS option is used directly as the maxTimeMS field on a command",
+      "operations": [
+        {
+          "name": "createEntities",
+          "object": "testRunner",
+          "arguments": {
+            "entities": [
+              {
+                "client": {
+                  "id": "client",
+                  "observeEvents": [
+                    "commandStartedEvent"
+                  ]
+                }
+              },
+              {
+                "database": {
+                  "id": "database",
+                  "client": "client",
+                  "databaseName": "test"
+                }
+              },
+              {
+                "collection": {
+                  "id": "collection",
+                  "database": "database",
+                  "collectionName": "coll"
+                }
+              }
+            ]
+          }
+        },
+        {
+          "name": "estimatedDocumentCount",
+          "object": "collection",
+          "arguments": {
+            "maxTimeMS": 50000
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "count",
+                "databaseName": "test",
+                "command": {
+                  "count": "coll",
+                  "maxTimeMS": 50000
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "maxCommitTimeMS option is used directly as the maxTimeMS field on a commitTransaction command",
+      "runOnRequirements": [
+        {
+          "topologies": [
+            "replicaset",
+            "sharded-replicaset"
+          ]
+        }
+      ],
+      "operations": [
+        {
+          "name": "createEntities",
+          "object": "testRunner",
+          "arguments": {
+            "entities": [
+              {
+                "client": {
+                  "id": "client",
+                  "observeEvents": [
+                    "commandStartedEvent"
+                  ]
+                }
+              },
+              {
+                "database": {
+                  "id": "database",
+                  "client": "client",
+                  "databaseName": "test"
+                }
+              },
+              {
+                "collection": {
+                  "id": "collection",
+                  "database": "database",
+                  "collectionName": "coll"
+                }
+              },
+              {
+                "session": {
+                  "id": "session",
+                  "client": "client",
+                  "sessionOptions": {
+                    "defaultTransactionOptions": {
+                      "maxCommitTimeMS": 1000
+                    }
+                  }
+                }
+              }
+            ]
+          }
+        },
+        {
+          "name": "startTransaction",
+          "object": "session"
+        },
+        {
+          "name": "insertOne",
+          "object": "collection",
+          "arguments": {
+            "document": {
+              "_id": 1
+            },
+            "session": "session"
+          }
+        },
+        {
+          "name": "commitTransaction",
+          "object": "session"
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "commitTransaction",
+                "databaseName": "admin",
+                "command": {
+                  "commitTransaction": 1,
+                  "maxTimeMS": 1000
+                }
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/csot/non-tailable-cursors.json

@@ -0,0 +1,541 @@
+{
+  "description": "timeoutMS behaves correctly for non-tailable cursors",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "uriOptions": {
+          "timeoutMS": 10
+        },
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent"
+        ],
+        "ignoreCommandMonitoringEvents": [
+          "killCursors"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection",
+        "database": "database",
+        "collectionName": "coll"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll",
+      "databaseName": "test",
+      "documents": [
+        {
+          "_id": 0
+        },
+        {
+          "_id": 1
+        },
+        {
+          "_id": 2
+        }
+      ]
+    },
+    {
+      "collectionName": "aggregateOutputColl",
+      "databaseName": "test",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "timeoutMS applied to find if timeoutMode is cursor_lifetime",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "find"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "find",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "timeoutMode": "cursorLifetime"
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "remaining timeoutMS applied to getMore if timeoutMode is unset",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "find",
+                  "getMore"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "find",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "timeoutMS": 20,
+            "batchSize": 2
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "remaining timeoutMS applied to getMore if timeoutMode is cursor_lifetime",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "find",
+                  "getMore"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "find",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "timeoutMode": "cursorLifetime",
+            "timeoutMS": 20,
+            "batchSize": 2
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to find if timeoutMode is iteration",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "find"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "find",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "timeoutMode": "iteration"
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS is refreshed for getMore if timeoutMode is iteration - success",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "find",
+                  "getMore"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "find",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "timeoutMode": "iteration",
+            "timeoutMS": 20,
+            "batchSize": 2
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS is refreshed for getMore if timeoutMode is iteration - failure",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "getMore"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "find",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "timeoutMode": "iteration",
+            "batchSize": 2
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "aggregate with $out errors if timeoutMode is iteration",
+      "operations": [
+        {
+          "name": "aggregate",
+          "object": "collection",
+          "arguments": {
+            "pipeline": [
+              {
+                "$out": "aggregateOutputColl"
+              }
+            ],
+            "timeoutMS": 100,
+            "timeoutMode": "iteration"
+          },
+          "expectError": {
+            "isClientError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": []
+        }
+      ]
+    },
+    {
+      "description": "aggregate with $merge errors if timeoutMode is iteration",
+      "operations": [
+        {
+          "name": "aggregate",
+          "object": "collection",
+          "arguments": {
+            "pipeline": [
+              {
+                "$merge": "aggregateOutputColl"
+              }
+            ],
+            "timeoutMS": 100,
+            "timeoutMode": "iteration"
+          },
+          "expectError": {
+            "isClientError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": []
+        }
+      ]
+    }
+  ]
+}

test/csot/sessions-inherit-timeoutMS.json

@@ -0,0 +1,311 @@
+{
+  "description": "sessions inherit timeoutMS from their parent MongoClient",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4",
+      "topologies": [
+        "replicaset",
+        "sharded-replicaset"
+      ]
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "uriOptions": {
+          "timeoutMS": 50
+        },
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent",
+          "commandSucceededEvent",
+          "commandFailedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection",
+        "database": "database",
+        "collectionName": "coll"
+      }
+    },
+    {
+      "session": {
+        "id": "session",
+        "client": "client"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll",
+      "databaseName": "test",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "timeoutMS applied to commitTransaction",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "commitTransaction"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 60
+              }
+            }
+          }
+        },
+        {
+          "name": "startTransaction",
+          "object": "session"
+        },
+        {
+          "name": "insertOne",
+          "object": "collection",
+          "arguments": {
+            "session": "session",
+            "document": {
+              "_id": 1
+            }
+          }
+        },
+        {
+          "name": "commitTransaction",
+          "object": "session",
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll"
+                }
+              }
+            },
+            {
+              "commandSucceededEvent": {
+                "commandName": "insert"
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "commitTransaction",
+                "databaseName": "admin",
+                "command": {
+                  "commitTransaction": 1,
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandFailedEvent": {
+                "commandName": "commitTransaction"
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to abortTransaction",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "abortTransaction"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 60
+              }
+            }
+          }
+        },
+        {
+          "name": "startTransaction",
+          "object": "session"
+        },
+        {
+          "name": "insertOne",
+          "object": "collection",
+          "arguments": {
+            "session": "session",
+            "document": {
+              "_id": 1
+            }
+          }
+        },
+        {
+          "name": "abortTransaction",
+          "object": "session"
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll"
+                }
+              }
+            },
+            {
+              "commandSucceededEvent": {
+                "commandName": "insert"
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "abortTransaction",
+                "databaseName": "admin",
+                "command": {
+                  "abortTransaction": 1,
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandFailedEvent": {
+                "commandName": "abortTransaction"
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to withTransaction",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "insert"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 60
+              }
+            }
+          }
+        },
+        {
+          "name": "withTransaction",
+          "object": "session",
+          "arguments": {
+            "callback": [
+              {
+                "name": "insertOne",
+                "object": "collection",
+                "arguments": {
+                  "session": "session",
+                  "document": {
+                    "_id": 1
+                  }
+                },
+                "expectError": {
+                  "isTimeoutError": true
+                }
+              }
+            ]
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandFailedEvent": {
+                "commandName": "insert"
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/csot/sessions-override-operation-timeoutMS.json

@@ -0,0 +1,315 @@
+{
+  "description": "timeoutMS can be overridden for individual session operations",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4",
+      "topologies": [
+        "replicaset",
+        "sharded-replicaset"
+      ]
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent",
+          "commandSucceededEvent",
+          "commandFailedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection",
+        "database": "database",
+        "collectionName": "coll"
+      }
+    },
+    {
+      "session": {
+        "id": "session",
+        "client": "client"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll",
+      "databaseName": "test",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "timeoutMS can be overridden for commitTransaction",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "commitTransaction"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 60
+              }
+            }
+          }
+        },
+        {
+          "name": "startTransaction",
+          "object": "session"
+        },
+        {
+          "name": "insertOne",
+          "object": "collection",
+          "arguments": {
+            "session": "session",
+            "document": {
+              "_id": 1
+            }
+          }
+        },
+        {
+          "name": "commitTransaction",
+          "object": "session",
+          "arguments": {
+            "timeoutMS": 50
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll"
+                }
+              }
+            },
+            {
+              "commandSucceededEvent": {
+                "commandName": "insert"
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "commitTransaction",
+                "databaseName": "admin",
+                "command": {
+                  "commitTransaction": 1,
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandFailedEvent": {
+                "commandName": "commitTransaction"
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to abortTransaction",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "abortTransaction"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 60
+              }
+            }
+          }
+        },
+        {
+          "name": "startTransaction",
+          "object": "session"
+        },
+        {
+          "name": "insertOne",
+          "object": "collection",
+          "arguments": {
+            "session": "session",
+            "document": {
+              "_id": 1
+            }
+          }
+        },
+        {
+          "name": "abortTransaction",
+          "object": "session",
+          "arguments": {
+            "timeoutMS": 50
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll"
+                }
+              }
+            },
+            {
+              "commandSucceededEvent": {
+                "commandName": "insert"
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "abortTransaction",
+                "databaseName": "admin",
+                "command": {
+                  "abortTransaction": 1,
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandFailedEvent": {
+                "commandName": "abortTransaction"
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to withTransaction",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "insert"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 60
+              }
+            }
+          }
+        },
+        {
+          "name": "withTransaction",
+          "object": "session",
+          "arguments": {
+            "timeoutMS": 50,
+            "callback": [
+              {
+                "name": "insertOne",
+                "object": "collection",
+                "arguments": {
+                  "session": "session",
+                  "document": {
+                    "_id": 1
+                  }
+                },
+                "expectError": {
+                  "isTimeoutError": true
+                }
+              }
+            ]
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandFailedEvent": {
+                "commandName": "insert"
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/csot/sessions-override-timeoutMS.json

@@ -0,0 +1,311 @@
+{
+  "description": "timeoutMS can be overridden at the level of a ClientSession",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4",
+      "topologies": [
+        "replicaset",
+        "sharded-replicaset"
+      ]
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent",
+          "commandSucceededEvent",
+          "commandFailedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection",
+        "database": "database",
+        "collectionName": "coll"
+      }
+    },
+    {
+      "session": {
+        "id": "session",
+        "client": "client",
+        "sessionOptions": {
+          "defaultTimeoutMS": 50
+        }
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll",
+      "databaseName": "test",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "timeoutMS applied to commitTransaction",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "commitTransaction"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 60
+              }
+            }
+          }
+        },
+        {
+          "name": "startTransaction",
+          "object": "session"
+        },
+        {
+          "name": "insertOne",
+          "object": "collection",
+          "arguments": {
+            "session": "session",
+            "document": {
+              "_id": 1
+            }
+          }
+        },
+        {
+          "name": "commitTransaction",
+          "object": "session",
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll"
+                }
+              }
+            },
+            {
+              "commandSucceededEvent": {
+                "commandName": "insert"
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "commitTransaction",
+                "databaseName": "admin",
+                "command": {
+                  "commitTransaction": 1,
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandFailedEvent": {
+                "commandName": "commitTransaction"
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to abortTransaction",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "abortTransaction"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 60
+              }
+            }
+          }
+        },
+        {
+          "name": "startTransaction",
+          "object": "session"
+        },
+        {
+          "name": "insertOne",
+          "object": "collection",
+          "arguments": {
+            "session": "session",
+            "document": {
+              "_id": 1
+            }
+          }
+        },
+        {
+          "name": "abortTransaction",
+          "object": "session"
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll"
+                }
+              }
+            },
+            {
+              "commandSucceededEvent": {
+                "commandName": "insert"
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "abortTransaction",
+                "databaseName": "admin",
+                "command": {
+                  "abortTransaction": 1,
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandFailedEvent": {
+                "commandName": "abortTransaction"
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to withTransaction",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "insert"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 60
+              }
+            }
+          }
+        },
+        {
+          "name": "withTransaction",
+          "object": "session",
+          "arguments": {
+            "callback": [
+              {
+                "name": "insertOne",
+                "object": "collection",
+                "arguments": {
+                  "session": "session",
+                  "document": {
+                    "_id": 1
+                  }
+                },
+                "expectError": {
+                  "isTimeoutError": true
+                }
+              }
+            ]
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "insert",
+                "databaseName": "test",
+                "command": {
+                  "insert": "coll",
+                  "maxTimeMS": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  }
+                }
+              }
+            },
+            {
+              "commandFailedEvent": {
+                "commandName": "insert"
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/csot/tailable-awaitData.json

@@ -0,0 +1,422 @@
+{
+  "description": "timeoutMS behaves correctly for tailable awaitData cursors",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "uriOptions": {
+          "timeoutMS": 10
+        },
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection",
+        "database": "database",
+        "collectionName": "coll"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll",
+      "databaseName": "test",
+      "createOptions": {
+        "capped": true,
+        "size": 500
+      },
+      "documents": [
+        {
+          "_id": 0
+        },
+        {
+          "_id": 1
+        }
+      ]
+    }
+  ],
+  "tests": [
+    {
+      "description": "error if timeoutMode is cursor_lifetime",
+      "operations": [
+        {
+          "name": "find",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "timeoutMode": "cursorLifetime",
+            "cursorType": "tailableAwait"
+          },
+          "expectError": {
+            "isClientError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "error if maxAwaitTimeMS is greater than timeoutMS",
+      "operations": [
+        {
+          "name": "find",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "cursorType": "tailableAwait",
+            "timeoutMS": 5,
+            "maxAwaitTimeMS": 10
+          },
+          "expectError": {
+            "isClientError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "error if maxAwaitTimeMS is equal to timeoutMS",
+      "operations": [
+        {
+          "name": "find",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "cursorType": "tailableAwait",
+            "timeoutMS": 5,
+            "maxAwaitTimeMS": 5
+          },
+          "expectError": {
+            "isClientError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to find",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "find"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "find",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "cursorType": "tailableAwait"
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "coll",
+                  "tailable": true,
+                  "awaitData": true,
+                  "maxTimeMS": {
+                    "$$exists": true
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS is refreshed for getMore if maxAwaitTimeMS is not set",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "find",
+                  "getMore"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "createFindCursor",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "cursorType": "tailableAwait",
+            "timeoutMS": 20,
+            "batchSize": 1
+          },
+          "saveResultAsEntity": "tailableCursor"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "tailableCursor"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "tailableCursor"
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "coll",
+                  "tailable": true,
+                  "awaitData": true,
+                  "maxTimeMS": {
+                    "$$exists": true
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS is refreshed for getMore if maxAwaitTimeMS is set",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "find",
+                  "getMore"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "createFindCursor",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "cursorType": "tailableAwait",
+            "timeoutMS": 20,
+            "batchSize": 1,
+            "maxAwaitTimeMS": 1
+          },
+          "saveResultAsEntity": "tailableCursor"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "tailableCursor"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "tailableCursor"
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "coll",
+                  "tailable": true,
+                  "awaitData": true,
+                  "maxTimeMS": {
+                    "$$exists": true
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll",
+                  "maxTimeMS": 1
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS is refreshed for getMore - failure",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "getMore"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "createFindCursor",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "cursorType": "tailableAwait",
+            "batchSize": 1
+          },
+          "saveResultAsEntity": "tailableCursor"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "tailableCursor"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "tailableCursor",
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "coll",
+                  "tailable": true,
+                  "awaitData": true,
+                  "maxTimeMS": {
+                    "$$exists": true
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll"
+                }
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/csot/tailable-non-awaitData.json

@@ -0,0 +1,312 @@
+{
+  "description": "timeoutMS behaves correctly for tailable non-awaitData cursors",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "4.4"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "failPointClient",
+        "useMultipleMongoses": false
+      }
+    },
+    {
+      "client": {
+        "id": "client",
+        "uriOptions": {
+          "timeoutMS": 10
+        },
+        "useMultipleMongoses": false,
+        "observeEvents": [
+          "commandStartedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection",
+        "database": "database",
+        "collectionName": "coll"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll",
+      "databaseName": "test",
+      "createOptions": {
+        "capped": true,
+        "size": 500
+      },
+      "documents": [
+        {
+          "_id": 0
+        },
+        {
+          "_id": 1
+        }
+      ]
+    }
+  ],
+  "tests": [
+    {
+      "description": "error if timeoutMode is cursor_lifetime",
+      "operations": [
+        {
+          "name": "find",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "timeoutMode": "cursorLifetime",
+            "cursorType": "tailable"
+          },
+          "expectError": {
+            "isClientError": true
+          }
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS applied to find",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "find"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "find",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "cursorType": "tailable"
+          },
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "coll",
+                  "tailable": true,
+                  "awaitData": {
+                    "$$exists": false
+                  },
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS is refreshed for getMore - success",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 2
+              },
+              "data": {
+                "failCommands": [
+                  "find",
+                  "getMore"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "createFindCursor",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "cursorType": "tailable",
+            "timeoutMS": 20,
+            "batchSize": 1
+          },
+          "saveResultAsEntity": "tailableCursor"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "tailableCursor"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "tailableCursor"
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "coll",
+                  "tailable": true,
+                  "awaitData": {
+                    "$$exists": false
+                  },
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "timeoutMS is refreshed for getMore - failure",
+      "operations": [
+        {
+          "name": "failPoint",
+          "object": "testRunner",
+          "arguments": {
+            "client": "failPointClient",
+            "failPoint": {
+              "configureFailPoint": "failCommand",
+              "mode": {
+                "times": 1
+              },
+              "data": {
+                "failCommands": [
+                  "getMore"
+                ],
+                "blockConnection": true,
+                "blockTimeMS": 15
+              }
+            }
+          }
+        },
+        {
+          "name": "createFindCursor",
+          "object": "collection",
+          "arguments": {
+            "filter": {},
+            "cursorType": "tailable",
+            "batchSize": 1
+          },
+          "saveResultAsEntity": "tailableCursor"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "tailableCursor"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "tailableCursor",
+          "expectError": {
+            "isTimeoutError": true
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "commandName": "find",
+                "databaseName": "test",
+                "command": {
+                  "find": "coll",
+                  "tailable": true,
+                  "awaitData": {
+                    "$$exists": false
+                  },
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "commandName": "getMore",
+                "databaseName": "test",
+                "command": {
+                  "getMore": {
+                    "$$type": [
+                      "int",
+                      "long"
+                    ]
+                  },
+                  "collection": "coll",
+                  "maxTimeMS": {
+                    "$$exists": false
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/test_csot.py

@@ -0,0 +1,32 @@
+# Copyright 2022-present MongoDB, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Test the CSOT unified spec tests."""
+
+import os
+import sys
+
+sys.path[0:0] = [""]
+
+from test import unittest
+from test.unified_format import generate_test_classes
+
+# Location of JSON test specifications.
+TEST_PATH = os.path.join(os.path.dirname(os.path.realpath(__file__)), "csot")
+
+# Generate unified tests.
+globals().update(generate_test_classes(TEST_PATH, module=__name__))
+
+if __name__ == "__main__":
+    unittest.main()

test/test_discovery_and_monitoring.py

@@ -395,7 +395,7 @@ class TestIntegration(SpecRunner):
         """Run the recordPrimary test operation."""
         self._previous_primary = self.scenario_client.primary
 
-    def wait_for_primary_change(self, timeout_ms):
+    def wait_for_primary_change(self, timeout):
         """Run the waitForPrimaryChange test operation."""
 
         def primary_changed():
@@ -404,7 +404,6 @@ class TestIntegration(SpecRunner):
                 return False
             return primary != self._previous_primary
 
-        timeout = timeout_ms / 1000.0
         wait_until(primary_changed, "change primary", timeout=timeout)
 
     def wait(self, ms):

test/transactions/legacy/error-labels-blockConnection.json

@@ -0,0 +1,159 @@
+{
+  "runOn": [
+    {
+      "minServerVersion": "4.2",
+      "topology": [
+        "replicaset",
+        "sharded"
+      ]
+    }
+  ],
+  "database_name": "transaction-tests",
+  "collection_name": "test",
+  "data": [],
+  "tests": [
+    {
+      "description": "add RetryableWriteError and UnknownTransactionCommitResult labels to connection errors",
+      "clientOptions": {
+        "socketTimeoutMS": 100
+      },
+      "failPoint": {
+        "configureFailPoint": "failCommand",
+        "mode": {
+          "times": 2
+        },
+        "data": {
+          "failCommands": [
+            "commitTransaction"
+          ],
+          "blockConnection": true,
+          "blockTimeMS": 150
+        }
+      },
+      "operations": [
+        {
+          "name": "startTransaction",
+          "object": "session0"
+        },
+        {
+          "name": "insertOne",
+          "object": "collection",
+          "arguments": {
+            "session": "session0",
+            "document": {
+              "_id": 1
+            }
+          },
+          "result": {
+            "insertedId": 1
+          }
+        },
+        {
+          "name": "commitTransaction",
+          "object": "session0",
+          "result": {
+            "errorLabelsContain": [
+              "RetryableWriteError",
+              "UnknownTransactionCommitResult"
+            ],
+            "errorLabelsOmit": [
+              "TransientTransactionError"
+            ]
+          }
+        },
+        {
+          "name": "commitTransaction",
+          "object": "session0"
+        }
+      ],
+      "expectations": [
+        {
+          "command_started_event": {
+            "command": {
+              "insert": "test",
+              "documents": [
+                {
+                  "_id": 1
+                }
+              ],
+              "ordered": true,
+              "readConcern": null,
+              "lsid": "session0",
+              "txnNumber": {
+                "$numberLong": "1"
+              },
+              "startTransaction": true,
+              "autocommit": false,
+              "writeConcern": null
+            },
+            "command_name": "insert",
+            "database_name": "transaction-tests"
+          }
+        },
+        {
+          "command_started_event": {
+            "command": {
+              "commitTransaction": 1,
+              "lsid": "session0",
+              "txnNumber": {
+                "$numberLong": "1"
+              },
+              "startTransaction": null,
+              "autocommit": false,
+              "writeConcern": null
+            },
+            "command_name": "commitTransaction",
+            "database_name": "admin"
+          }
+        },
+        {
+          "command_started_event": {
+            "command": {
+              "commitTransaction": 1,
+              "lsid": "session0",
+              "txnNumber": {
+                "$numberLong": "1"
+              },
+              "startTransaction": null,
+              "autocommit": false,
+              "writeConcern": {
+                "w": "majority",
+                "wtimeout": 10000
+              }
+            },
+            "command_name": "commitTransaction",
+            "database_name": "admin"
+          }
+        },
+        {
+          "command_started_event": {
+            "command": {
+              "commitTransaction": 1,
+              "lsid": "session0",
+              "txnNumber": {
+                "$numberLong": "1"
+              },
+              "startTransaction": null,
+              "autocommit": false,
+              "writeConcern": {
+                "w": "majority",
+                "wtimeout": 10000
+              }
+            },
+            "command_name": "commitTransaction",
+            "database_name": "admin"
+          }
+        }
+      ],
+      "outcome": {
+        "collection": {
+          "data": [
+            {
+              "_id": 1
+            }
+          ]
+        }
+      }
+    }
+  ]
+}

test/unified-test-format/invalid/collectionData-additionalProperties.json

@@ -18,8 +18,7 @@
       "collection": {
         "id": "collection0",
         "database": "database0",
-        "collectionName": "foo",
-        "foo": 0
+        "collectionName": "foo"
       }
     }
   ],

test/unified-test-format/invalid/collectionData-collectionName-required.json

@@ -18,8 +18,7 @@
       "collection": {
         "id": "collection0",
         "database": "database0",
-        "collectionName": "foo",
-        "foo": 0
+        "collectionName": "foo"
       }
     }
   ],

test/unified-test-format/invalid/collectionData-collectionName-type.json

@@ -18,8 +18,7 @@
       "collection": {
         "id": "collection0",
         "database": "database0",
-        "collectionName": "foo",
-        "foo": 0
+        "collectionName": "foo"
       }
     }
   ],

test/unified-test-format/invalid/collectionData-createOptions-type.json

@@ -0,0 +1,39 @@
+{
+  "description": "collectionData-createOptions-type",
+  "schemaVersion": "1.9",
+  "createEntities": [
+    {
+      "client": {
+        "id": "client0"
+      }
+    },
+    {
+      "database": {
+        "id": "database0",
+        "client": "client0",
+        "databaseName": "foo"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection0",
+        "database": "database0",
+        "collectionName": "foo"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "foo",
+      "databaseName": "foo",
+      "createOptions": 0,
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "foo",
+      "operations": []
+    }
+  ]
+}

test/unified-test-format/invalid/collectionData-databaseName-required.json

@@ -18,8 +18,7 @@
       "collection": {
         "id": "collection0",
         "database": "database0",
-        "collectionName": "foo",
-        "foo": 0
+        "collectionName": "foo"
       }
     }
   ],

test/unified-test-format/invalid/collectionData-databaseName-type.json

@@ -18,8 +18,7 @@
       "collection": {
         "id": "collection0",
         "database": "database0",
-        "collectionName": "foo",
-        "foo": 0
+        "collectionName": "foo"
       }
     }
   ],

test/unified-test-format/invalid/collectionData-documents-items.json

@@ -18,8 +18,7 @@
       "collection": {
         "id": "collection0",
         "database": "database0",
-        "collectionName": "foo",
-        "foo": 0
+        "collectionName": "foo"
       }
     }
   ],

test/unified-test-format/invalid/collectionData-documents-required.json

@@ -18,8 +18,7 @@
       "collection": {
         "id": "collection0",
         "database": "database0",
-        "collectionName": "foo",
-        "foo": 0
+        "collectionName": "foo"
       }
     }
   ],

test/unified-test-format/invalid/collectionData-documents-type.json

@@ -18,8 +18,7 @@
       "collection": {
         "id": "collection0",
         "database": "database0",
-        "collectionName": "foo",
-        "foo": 0
+        "collectionName": "foo"
       }
     }
   ],

test/unified-test-format/invalid/collectionOrDatabaseOptions-timeoutMS-type.json

@@ -0,0 +1,27 @@
+{
+  "description": "collectionOrDatabaseOptions-timeoutMS-type",
+  "schemaVersion": "1.9",
+  "createEntities": [
+    {
+      "client": {
+        "id": "client0"
+      }
+    },
+    {
+      "database": {
+        "id": "database0",
+        "client": "client0",
+        "databaseName": "foo",
+        "databaseOptions": {
+          "timeoutMS": 4.5
+        }
+      }
+    }
+  ],
+  "tests": [
+    {
+      "description": "foo",
+      "operations": []
+    }
+  ]
+}

test/unified-test-format/invalid/expectedError-isTimeoutError-type.json

@@ -0,0 +1,25 @@
+{
+  "description": "expectedError-isTimeoutError-type",
+  "schemaVersion": "1.9",
+  "createEntities": [
+    {
+      "client": {
+        "id": "client0"
+      }
+    }
+  ],
+  "tests": [
+    {
+      "description": "foo",
+      "operations": [
+        {
+          "name": "foo",
+          "object": "client0",
+          "expectError": {
+            "isTimeoutError": 0
+          }
+        }
+      ]
+    }
+  ]
+}

test/unified-test-format/invalid/expectedEventsForClient-ignoreExtraEvents-type.json

@@ -0,0 +1,24 @@
+{
+  "description": "expectedEventsForClient-ignoreExtraEvents-type",
+  "schemaVersion": "1.7",
+  "createEntities": [
+    {
+      "client": {
+        "id": "client0"
+      }
+    }
+  ],
+  "tests": [
+    {
+      "description": "foo",
+      "operations": [],
+      "expectEvents": [
+        {
+          "client": "client0",
+          "events": [],
+          "ignoreExtraEvents": 0
+        }
+      ]
+    }
+  ]
+}

test/unified-test-format/valid-pass/collectionData-createOptions.json

@@ -0,0 +1,68 @@
+{
+  "description": "collectionData-createOptions",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "3.6"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "client0"
+      }
+    },
+    {
+      "database": {
+        "id": "database0",
+        "client": "client0",
+        "databaseName": "database0"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection0",
+        "database": "database0",
+        "collectionName": "coll0"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll0",
+      "databaseName": "database0",
+      "createOptions": {
+        "capped": true,
+        "size": 512
+      },
+      "documents": [
+        {
+          "_id": 1,
+          "x": 11
+        }
+      ]
+    }
+  ],
+  "tests": [
+    {
+      "description": "collection is created with the correct options",
+      "operations": [
+        {
+          "name": "runCommand",
+          "object": "database0",
+          "arguments": {
+            "commandName": "collStats",
+            "command": {
+              "collStats": "coll0",
+              "scale": 1
+            }
+          },
+          "expectResult": {
+            "capped": true,
+            "maxSize": 512
+          }
+        }
+      ]
+    }
+  ]
+}

test/unified-test-format/valid-pass/createEntities-operation.json

@@ -0,0 +1,74 @@
+{
+  "description": "createEntities-operation",
+  "schemaVersion": "1.9",
+  "tests": [
+    {
+      "description": "createEntities operation",
+      "operations": [
+        {
+          "name": "createEntities",
+          "object": "testRunner",
+          "arguments": {
+            "entities": [
+              {
+                "client": {
+                  "id": "client1",
+                  "observeEvents": [
+                    "commandStartedEvent"
+                  ]
+                }
+              },
+              {
+                "database": {
+                  "id": "database1",
+                  "client": "client1",
+                  "databaseName": "database1"
+                }
+              },
+              {
+                "collection": {
+                  "id": "collection1",
+                  "database": "database1",
+                  "collectionName": "coll1"
+                }
+              }
+            ]
+          }
+        },
+        {
+          "name": "deleteOne",
+          "object": "collection1",
+          "arguments": {
+            "filter": {
+              "_id": 1
+            }
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client1",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "command": {
+                  "delete": "coll1",
+                  "deletes": [
+                    {
+                      "q": {
+                        "_id": 1
+                      },
+                      "limit": 1
+                    }
+                  ]
+                },
+                "commandName": "delete",
+                "databaseName": "database1"
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/unified-test-format/valid-pass/entity-cursor-iterateOnce.json

@@ -0,0 +1,108 @@
+{
+  "description": "entity-cursor-iterateOnce",
+  "schemaVersion": "1.9",
+  "createEntities": [
+    {
+      "client": {
+        "id": "client0",
+        "observeEvents": [
+          "commandStartedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database0",
+        "client": "client0",
+        "databaseName": "database0"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection0",
+        "database": "database0",
+        "collectionName": "coll0"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "databaseName": "database0",
+      "collectionName": "coll0",
+      "documents": [
+        {
+          "_id": 1
+        },
+        {
+          "_id": 2
+        },
+        {
+          "_id": 3
+        }
+      ]
+    }
+  ],
+  "tests": [
+    {
+      "description": "iterateOnce",
+      "operations": [
+        {
+          "name": "createFindCursor",
+          "object": "collection0",
+          "arguments": {
+            "filter": {},
+            "batchSize": 2
+          },
+          "saveResultAsEntity": "cursor0"
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "cursor0",
+          "expectResult": {
+            "_id": 1
+          }
+        },
+        {
+          "name": "iterateUntilDocumentOrError",
+          "object": "cursor0",
+          "expectResult": {
+            "_id": 2
+          }
+        },
+        {
+          "name": "iterateOnce",
+          "object": "cursor0"
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client0",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "command": {
+                  "find": "coll0",
+                  "filter": {},
+                  "batchSize": 2
+                },
+                "commandName": "find",
+                "databaseName": "database0"
+              }
+            },
+            {
+              "commandStartedEvent": {
+                "command": {
+                  "getMore": {
+                    "$$type": "long"
+                  },
+                  "collection": "coll0"
+                },
+                "commandName": "getMore"
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/unified-test-format/valid-pass/matches-lte-operator.json

@@ -0,0 +1,78 @@
+{
+  "description": "matches-lte-operator",
+  "schemaVersion": "1.9",
+  "createEntities": [
+    {
+      "client": {
+        "id": "client0",
+        "observeEvents": [
+          "commandStartedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database0",
+        "client": "client0",
+        "databaseName": "database0Name"
+      }
+    },
+    {
+      "collection": {
+        "id": "collection0",
+        "database": "database0",
+        "collectionName": "coll0"
+      }
+    }
+  ],
+  "initialData": [
+    {
+      "collectionName": "coll0",
+      "databaseName": "database0Name",
+      "documents": []
+    }
+  ],
+  "tests": [
+    {
+      "description": "special lte matching operator",
+      "operations": [
+        {
+          "name": "insertOne",
+          "object": "collection0",
+          "arguments": {
+            "document": {
+              "_id": 1,
+              "y": 1
+            }
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client0",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "command": {
+                  "insert": "coll0",
+                  "documents": [
+                    {
+                      "_id": {
+                        "$$lte": 1
+                      },
+                      "y": {
+                        "$$lte": 2
+                      }
+                    }
+                  ]
+                },
+                "commandName": "insert",
+                "databaseName": "database0Name"
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/unified_format.py

@@ -42,6 +42,7 @@ from test.utils import (
 from test.version import Version
 from typing import Any
 
+import pymongo
 from bson import SON, Code, DBRef, Decimal128, Int64, MaxKey, MinKey, json_util
 from bson.binary import Binary
 from bson.objectid import ObjectId
@@ -56,9 +57,13 @@ from pymongo.errors import (
     BulkWriteError,
     ConfigurationError,
     ConnectionFailure,
+    ExecutionTimeout,
     InvalidOperation,
+    NetworkTimeout,
     NotPrimaryError,
     PyMongoError,
+    ServerSelectionTimeoutError,
+    WriteConcernError,
 )
 from pymongo.monitoring import (
     _SENSITIVE_COMMANDS,
@@ -198,11 +203,16 @@ def parse_bulk_write_error_result(error):
 class NonLazyCursor(object):
     """A find cursor proxy that creates the remote cursor when initialized."""
 
-    def __init__(self, find_cursor):
+    def __init__(self, find_cursor, client):
+        self.client = client
         self.find_cursor = find_cursor
         # Create the server side cursor.
         self.first_result = next(find_cursor, None)
 
+    @property
+    def alive(self):
+        return self.first_result is not None or self.find_cursor.alive
+
     def __next__(self):
         if self.first_result is not None:
             first = self.first_result
@@ -210,8 +220,12 @@ class NonLazyCursor(object):
             return first
         return next(self.find_cursor)
 
+    # Added to support the iterateOnce operation.
+    try_next = __next__
+
     def close(self):
         self.find_cursor.close()
+        self.client = None
 
 
 class EventListenerUtil(CMAPListener, CommandListener):
@@ -520,6 +534,11 @@ class MatchEvaluatorUtil(object):
         expected_lsid = self.test.entity_map.get_lsid_for_session(spec)
         self.test.assertEqual(expected_lsid, actual[key_to_compare])
 
+    def _operation_lte(self, spec, actual, key_to_compare):
+        if key_to_compare not in actual:
+            self.test.fail(f"Actual command is missing the {key_to_compare} field: {spec}")
+        self.test.assertLessEqual(actual[key_to_compare], spec)
+
     def _evaluate_special_operation(self, opname, spec, actual, key_to_compare):
         method_name = "_operation_%s" % (opname.strip("$"),)
         try:
@@ -710,7 +729,7 @@ class UnifiedSpecTestMixinV1(IntegrationTest):
     a class attribute ``TEST_SPEC``.
     """
 
-    SCHEMA_VERSION = Version.from_string("1.7")
+    SCHEMA_VERSION = Version.from_string("1.9")
     RUN_ON_LOAD_BALANCER = True
     RUN_ON_SERVERLESS = True
     TEST_SPEC: Any
@@ -730,6 +749,7 @@ class UnifiedSpecTestMixinV1(IntegrationTest):
         for i, collection_data in enumerate(initial_data):
             coll_name = collection_data["collectionName"]
             db_name = collection_data["databaseName"]
+            opts = collection_data.get("createOptions", {})
             documents = collection_data["documents"]
 
             # Setup the collection with as few majority writes as possible.
@@ -741,10 +761,12 @@ class UnifiedSpecTestMixinV1(IntegrationTest):
             else:
                 wc = WriteConcern(w=1)
             if documents:
+                if opts:
+                    db.create_collection(coll_name, **opts)
                 db.get_collection(coll_name, write_concern=wc).insert_many(documents)
             else:
                 # Ensure collection exists
-                db.create_collection(coll_name, write_concern=wc)
+                db.create_collection(coll_name, write_concern=wc, **opts)
 
     @classmethod
     def setUpClass(cls):
@@ -782,9 +804,26 @@ class UnifiedSpecTestMixinV1(IntegrationTest):
                 "Dirty explicit session is discarded" in spec["description"]
                 or "Dirty implicit session is discarded" in spec["description"]
             ):
-                raise unittest.SkipTest("MMAPv1 does not support retryWrites=True")
+                self.skipTest("MMAPv1 does not support retryWrites=True")
         elif "Client side error in command starting transaction" in spec["description"]:
-            raise unittest.SkipTest("Implement PYTHON-1894")
+            self.skipTest("Implement PYTHON-1894")
+        class_name = self.__class__.__name__.lower()
+        description = spec["description"].lower()
+        if "csot" in class_name:
+            if "change" in description or "change" in class_name:
+                self.skipTest("CSOT not implemented for watch()")
+            if "cursors" in class_name:
+                self.skipTest("CSOT not implemented for cursors")
+            if "tailable" in class_name:
+                self.skipTest("CSOT not implemented for tailable cursors")
+            if "sessions" in class_name:
+                self.skipTest("CSOT not implemented for sessions")
+            if "withtransaction" in description:
+                self.skipTest("CSOT not implemented for with_transaction")
+            if "transaction" in class_name or "transaction" in description:
+                self.skipTest("CSOT not implemented for transactions")
+            if "socket timeout" in description:
+                self.skipTest("CSOT not implemented for socket timeouts")
 
         # Some tests need to be skipped based on the operations they try to run.
         for op in spec["operations"]:
@@ -801,10 +840,21 @@ class UnifiedSpecTestMixinV1(IntegrationTest):
             if not client_context.test_commands_enabled:
                 if name == "failPoint" or name == "targetedFailPoint":
                     self.skipTest("Test commands must be enabled to use fail points")
+            if "timeoutMode" in op.get("arguments", {}):
+                self.skipTest("PyMongo does not support timeoutMode")
+            if name == "createEntities":
+                self.maybe_skip_entity(op.get("arguments", {}).get("entities", []))
+
+    def maybe_skip_entity(self, entities):
+        for entity in entities:
+            entity_type = next(iter(entity))
+            if entity_type == "bucket":
+                self.skipTest("GridFS is not currently supported (PYTHON-2459)")
 
     def process_error(self, exception, spec):
         is_error = spec.get("isError")
         is_client_error = spec.get("isClientError")
+        is_timeout_error = spec.get("isTimeoutError")
         error_contains = spec.get("errorContains")
         error_code = spec.get("errorCode")
         error_code_name = spec.get("errorCodeName")
@@ -825,6 +875,15 @@ class UnifiedSpecTestMixinV1(IntegrationTest):
             else:
                 self.assertNotIsInstance(exception, PyMongoError)
 
+        if is_timeout_error:
+            # TODO: PYTHON-3291 Implement error transformation.
+            if isinstance(exception, WriteConcernError):
+                self.assertEqual(exception.code, 50)
+            else:
+                self.assertIsInstance(
+                    exception, (NetworkTimeout, ExecutionTimeout, ServerSelectionTimeoutError)
+                )
+
         if error_contains:
             if isinstance(exception, BulkWriteError):
                 errmsg = str(exception.details).lower()
@@ -925,15 +984,21 @@ class UnifiedSpecTestMixinV1(IntegrationTest):
         self.__raise_if_unsupported("find", target, Collection)
         if "filter" not in kwargs:
             self.fail('createFindCursor requires a "filter" argument')
-        cursor = NonLazyCursor(target.find(*args, **kwargs))
+        cursor = NonLazyCursor(target.find(*args, **kwargs), target.database.client)
         self.addCleanup(cursor.close)
         return cursor
 
+    def _collectionOperation_count(self, target, *args, **kwargs):
+        self.skipTest("PyMongo does not support collection.count()")
+
     def _collectionOperation_listIndexes(self, target, *args, **kwargs):
         if "batch_size" in kwargs:
             self.skipTest("PyMongo does not support batch_size for list_indexes")
         return target.list_indexes(*args, **kwargs)
 
+    def _collectionOperation_listIndexNames(self, target, *args, **kwargs):
+        self.skipTest("PyMongo does not support list_index_names")
+
     def _sessionOperation_withTransaction(self, target, *args, **kwargs):
         if client_context.storage_engine == "mmapv1":
             self.skipTest("MMAPv1 does not support document-level locking")
@@ -946,13 +1011,21 @@ class UnifiedSpecTestMixinV1(IntegrationTest):
         self.__raise_if_unsupported("startTransaction", target, ClientSession)
         return target.start_transaction(*args, **kwargs)
 
+    def _cursor_iterateOnce(self, target, *args, **kwargs):
+        self.__raise_if_unsupported("iterateOnce", target, NonLazyCursor, ChangeStream)
+        return target.try_next()
+
     def _changeStreamOperation_iterateUntilDocumentOrError(self, target, *args, **kwargs):
         self.__raise_if_unsupported("iterateUntilDocumentOrError", target, ChangeStream)
         return next(target)
 
     def _cursor_iterateUntilDocumentOrError(self, target, *args, **kwargs):
         self.__raise_if_unsupported("iterateUntilDocumentOrError", target, NonLazyCursor)
-        return next(target)
+        while target.alive:
+            try:
+                return next(target)
+            except StopIteration:
+                pass
 
     def _cursor_close(self, target, *args, **kwargs):
         self.__raise_if_unsupported("close", target, NonLazyCursor)
@@ -960,6 +1033,7 @@ class UnifiedSpecTestMixinV1(IntegrationTest):
 
     def run_entity_operation(self, spec):
         target = self.entity_map[spec["object"]]
+        client = target
         opname = spec["name"]
         opargs = spec.get("arguments")
         expect_error = spec.get("expectError")
@@ -977,20 +1051,26 @@ class UnifiedSpecTestMixinV1(IntegrationTest):
                 spec, arguments, camel_to_snake(opname), self.entity_map, self.run_operations
             )
         else:
-            arguments = tuple()
+            arguments = {}
 
         if isinstance(target, MongoClient):
             method_name = "_clientOperation_%s" % (opname,)
+            client = target
         elif isinstance(target, Database):
             method_name = "_databaseOperation_%s" % (opname,)
+            client = target.client
         elif isinstance(target, Collection):
             method_name = "_collectionOperation_%s" % (opname,)
+            client = target.database.client
         elif isinstance(target, ChangeStream):
             method_name = "_changeStreamOperation_%s" % (opname,)
+            client = target._client
         elif isinstance(target, NonLazyCursor):
             method_name = "_cursor_%s" % (opname,)
+            client = target.client
         elif isinstance(target, ClientSession):
             method_name = "_sessionOperation_%s" % (opname,)
+            client = target._client
         elif isinstance(target, GridFSBucket):
             raise NotImplementedError
         else:
@@ -1007,7 +1087,17 @@ class UnifiedSpecTestMixinV1(IntegrationTest):
             cmd = functools.partial(method, target)
 
         try:
-            result = cmd(**dict(arguments))
+            # TODO: PYTHON-3289 apply inherited timeout by default.
+            inherit_timeout = getattr(target, "timeout", None)
+            # CSOT: Translate the spec test "timeout" arg into pymongo's context timeout API.
+            if "timeout" in arguments or inherit_timeout is not None:
+                timeout = arguments.pop("timeout", None)
+                if timeout is None:
+                    timeout = inherit_timeout
+                with pymongo.timeout(timeout):
+                    result = cmd(**dict(arguments))
+            else:
+                result = cmd(**dict(arguments))
         except Exception as exc:
             # Ignore all operation errors but to avoid masking bugs don't
             # ignore things like TypeError and ValueError.
@@ -1057,6 +1147,9 @@ class UnifiedSpecTestMixinV1(IntegrationTest):
         self.addCleanup(client.close)
         self.__set_fail_point(client=client, command_args=spec["failPoint"])
 
+    def _testOperation_createEntities(self, spec):
+        self.entity_map.create_entities_from_spec(spec["entities"], uri=self._uri)
+
     def _testOperation_assertSessionTransactionState(self, spec):
         session = self.entity_map[spec["session"]]
         expected_state = getattr(_TxnState, spec["state"].upper())
@@ -1245,6 +1338,7 @@ class UnifiedSpecTestMixinV1(IntegrationTest):
             raise unittest.SkipTest("%s" % (skip_reason,))
 
         # process createEntities
+        self._uri = uri
         self.entity_map = EntityMapUtil(self)
         self.entity_map.create_entities_from_spec(self.TEST_SPEC.get("createEntities", []), uri=uri)
         # process initialData
@@ -1309,7 +1403,7 @@ def generate_test_classes(
     class_name_prefix="",
     expected_failures=[],  # noqa: B006
     bypass_test_generation_errors=False,
-    **kwargs
+    **kwargs,
 ):
     """Method for generating test classes. Returns a dictionary where keys are
     the names of test classes and values are the test class objects."""

test/uri_options/connection-options.json

@@ -2,7 +2,7 @@
   "tests": [
     {
       "description": "Valid connection and timeout options are parsed correctly",
-      "uri": "mongodb://example.com/?appname=URI-OPTIONS-SPEC-TEST&connectTimeoutMS=20000&heartbeatFrequencyMS=5000&localThresholdMS=3000&maxIdleTimeMS=50000&replicaSet=uri-options-spec&retryWrites=true&serverSelectionTimeoutMS=15000&socketTimeoutMS=7500",
+      "uri": "mongodb://example.com/?appname=URI-OPTIONS-SPEC-TEST&connectTimeoutMS=20000&heartbeatFrequencyMS=5000&localThresholdMS=3000&maxIdleTimeMS=50000&replicaSet=uri-options-spec&retryWrites=true&serverSelectionTimeoutMS=15000&socketTimeoutMS=7500&timeoutMS=100",
       "valid": true,
       "warning": false,
       "hosts": null,
@@ -16,7 +16,8 @@
         "replicaSet": "uri-options-spec",
         "retryWrites": true,
         "serverSelectionTimeoutMS": 15000,
-        "socketTimeoutMS": 7500
+        "socketTimeoutMS": 7500,
+        "timeoutMS": 100
       }
     },
     {
@@ -238,6 +239,35 @@
       "hosts": null,
       "auth": null,
       "options": {}
+    },
+    {
+      "description": "timeoutMS=0",
+      "uri": "mongodb://example.com/?timeoutMS=0",
+      "valid": true,
+      "warning": false,
+      "hosts": null,
+      "auth": null,
+      "options": {
+        "timeoutMS": 0
+      }
+    },
+    {
+      "description": "Non-numeric timeoutMS causes a warning",
+      "uri": "mongodb://example.com/?timeoutMS=invalid",
+      "valid": true,
+      "warning": true,
+      "hosts": null,
+      "auth": null,
+      "options": {}
+    },
+    {
+      "description": "Too low timeoutMS causes a warning",
+      "uri": "mongodb://example.com/?timeoutMS=-2",
+      "valid": true,
+      "warning": true,
+      "hosts": null,
+      "auth": null,
+      "options": {}
     }
   ]
 }

test/uri_options/tls-options.json

@@ -44,15 +44,6 @@
         "tlsAllowInvalidCertificates": true
       }
     },
-    {
-      "description": "Invalid tlsAllowInvalidCertificates causes a warning",
-      "uri": "mongodb://example.com/?tlsAllowInvalidCertificates=invalid",
-      "valid": true,
-      "warning": true,
-      "hosts": null,
-      "auth": null,
-      "options": {}
-    },
     {
       "description": "tlsAllowInvalidHostnames is parsed correctly",
       "uri": "mongodb://example.com/?tlsAllowInvalidHostnames=true",

test/utils.py

@@ -35,6 +35,7 @@ from bson.objectid import ObjectId
 from bson.son import SON
 from pymongo import MongoClient, monitoring, operations, read_preferences
 from pymongo.collection import ReturnDocument
+from pymongo.cursor import CursorType
 from pymongo.errors import ConfigurationError, OperationFailure
 from pymongo.hello import HelloCompat
 from pymongo.monitoring import _SENSITIVE_COMMANDS
@@ -651,6 +652,9 @@ def parse_collection_options(opts):
 
     if "readConcern" in opts:
         opts["read_concern"] = ReadConcern(**dict(opts.pop("readConcern")))
+
+    if "timeoutMS" in opts:
+        opts["timeout"] = int(opts.pop("timeoutMS")) / 1000.0
     return opts
 
 
@@ -988,6 +992,10 @@ def parse_spec_options(opts):
     if "readConcern" in opts:
         opts["read_concern"] = ReadConcern(**dict(opts.pop("readConcern")))
 
+    if "timeoutMS" in opts:
+        assert isinstance(opts["timeoutMS"], int)
+        opts["timeout"] = int(opts.pop("timeoutMS")) / 1000.0
+
     if "maxTimeMS" in opts:
         opts["max_time_ms"] = opts.pop("maxTimeMS")
 
@@ -1041,6 +1049,8 @@ def prepare_spec_arguments(spec, arguments, opname, entity_map, with_txn_callbac
         # Aggregate uses "batchSize", while find uses batch_size.
         elif (arg_name == "batchSize" or arg_name == "allowDiskUse") and opname == "aggregate":
             continue
+        elif arg_name == "timeoutMode":
+            raise unittest.SkipTest("PyMongo does not support timeoutMode")
         # Requires boolean returnDocument.
         elif arg_name == "returnDocument":
             arguments[c2s] = getattr(ReturnDocument, arguments.pop(arg_name).upper())
@@ -1090,5 +1100,13 @@ def prepare_spec_arguments(spec, arguments, opname, entity_map, with_txn_callbac
             arguments["index_or_name"] = arguments.pop(arg_name)
         elif opname == "rename" and arg_name == "to":
             arguments["new_name"] = arguments.pop(arg_name)
+        elif arg_name == "cursorType":
+            cursor_type = arguments.pop(arg_name)
+            if cursor_type == "tailable":
+                arguments["cursor_type"] = CursorType.TAILABLE
+            elif cursor_type == "tailableAwait":
+                arguments["cursor_type"] = CursorType.TAILABLE
+            else:
+                assert False, f"Unsupported cursorType: {cursor_type}"
         else:
             arguments[c2s] = arguments.pop(arg_name)