Disable SRV Polling, SDAM compatibility check, logicalSessionTimeoutMinutes check.
server session pool pruning, server selection, and server monitoring.
A ServerType of LoadBalancer MUST be considered a data-bearing server.
"drivers MUST emit the following series of SDAM events" section.
Send loadBalanced:True with handshakes, validate serviceId.
Add topologyVersion fallback when serviceId is missing.
Don't mark load balancers unknown.
MongoClient now requires 2 connections and 2 threads to each MongoDB 4.4+ server.
With one connection, the server streams (or pushes) updated heartbeat info.
With the other connection, the client periodically pings the server to
establish an accurate round-trip time (RTT). This change optimizes the
discovery of server state changes such as replica set elections.
Additional changes:
- Mark server Unknown before retrying isMaster check.
- Always reset the pool _after_ marking the server unknown.
- Configure fail point before creating the client in test SpecRunner.
- Unfreeze with replSetFreeze:0 to ensure a speedy elections in test suite.
Add retryReads URI option that defaults to True.
Supported read operations will be retried once after transient
network, election, and shutdown errors on MongoDB 3.6+.
Supported operations are:
listCollections, listIndexes, and listDatabases
distinct
count, estimated_document_count, count_documents
aggregate (not including $out)
find (only for the initial find command, getMore commands are not
retried).
ChangeStreams: watch (initial aggregate command).
GridFS read APIs.
Test changes:
Add retryable reads spec test runner.
Disable retryable reads in network error tests.
In a sharded transaction, a session is pinned to the mongos server
selected for the initial command. All subsequent commands in the same
transaction are routed to the pinned mongos server.
We must get a socket *before* choosing whether to use write commands or legacy
writes. I will update the code in steps, getting a socket earlier and earlier
in the write path.
This commit gets a socket just before sending OP_INSERT in _do_batched_insert,
and temporarily disables the C version of _do_batched_insert.
Replace 5-sample moving average with exponentially weighted average,
required by the upcoming Server Selection Spec. Move responsibility for
tracking the average from ServerDescription to Monitor. Now the
ServerDescription only knows the average at the time it was created.
Rename the attributes of IsMaster, ServerDescription, TopologyDescription, and
TopologySettings from "set_name" to "replica_set_name" for greater clarity.
