# Copyright 2015-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 topology module's Server Selection Spec implementation.""" import os import sys from pymongo import MongoClient from pymongo import ReadPreference from pymongo.errors import ServerSelectionTimeoutError from pymongo.server_selectors import writable_server_selector from pymongo.settings import TopologySettings from pymongo.topology import Topology sys.path[0:0] = [""] from test import client_context, unittest, IntegrationTest from test.utils import rs_or_single_client, wait_until, EventListener from test.utils_selection_tests import ( create_selection_tests, get_addresses, get_topology_settings_dict, make_server_description) # Location of JSON test specifications. _TEST_PATH = os.path.join( os.path.dirname(os.path.realpath(__file__)), os.path.join('server_selection', 'server_selection')) class CallCountSelector(object): """No-op selector that keeps track of how many times it is called.""" def __init__(self): self.call_count = 0 def __call__(self, servers): self.call_count += 1 return servers class SelectionStoreSelector(object): """No-op selector that keeps track of what was passed to it.""" def __init__(self): self.selection = None def __call__(self, selection): self.selection = selection return selection class TestAllScenarios(create_selection_tests(_TEST_PATH)): pass class TestCustomServerSelectorFunction(IntegrationTest): @client_context.require_replica_set def test_functional_select_max_port_number_host(self): # Selector that returns server with highest port number. def custom_selector(servers): ports = [s.address[1] for s in servers] idx = ports.index(max(ports)) return [servers[idx]] # Initialize client with appropriate listeners. listener = EventListener() client = rs_or_single_client( server_selector=custom_selector, event_listeners=[listener]) self.addCleanup(client.close) coll = client.get_database( 'testdb', read_preference=ReadPreference.NEAREST).coll self.addCleanup(client.drop_database, 'testdb') # Wait the node list to be fully populated. def all_hosts_started(): return (len(client.admin.command('isMaster')['hosts']) == len(client._topology._description.readable_servers)) wait_until(all_hosts_started, 'receive heartbeat from all hosts') expected_port = max([ n.address[1] for n in client._topology._description.readable_servers]) # Insert 1 record and access it 10 times. coll.insert_one({'name': 'John Doe'}) for _ in range(10): coll.find_one({'name': 'John Doe'}) # Confirm all find commands are run against appropriate host. for command in listener.results['started']: if command.command_name == 'find': self.assertEqual( command.connection_id[1], expected_port) def test_invalid_server_selector(self): # Client initialization must fail if server_selector is not callable. for selector_candidate in [list(), 10, 'string', {}]: with self.assertRaisesRegex(ValueError, "must be a callable"): MongoClient(connect=False, server_selector=selector_candidate) # None value for server_selector is OK. MongoClient(connect=False, server_selector=None) @client_context.require_replica_set def test_selector_called(self): selector = CallCountSelector() # Client setup. mongo_client = rs_or_single_client(server_selector=selector) test_collection = mongo_client.testdb.test_collection self.addCleanup(mongo_client.drop_database, 'testdb') self.addCleanup(mongo_client.close) # Do N operations and test selector is called at least N times. test_collection.insert_one({'age': 20, 'name': 'John'}) test_collection.insert_one({'age': 31, 'name': 'Jane'}) test_collection.update_one({'name': 'Jane'}, {'$set': {'age': 21}}) test_collection.find_one({'name': 'Roe'}) self.assertGreaterEqual(selector.call_count, 4) @client_context.require_replica_set def test_latency_threshold_application(self): selector = SelectionStoreSelector() scenario_def = { 'topology_description': { 'type': 'ReplicaSetWithPrimary', 'servers': [ {'address': 'b:27017', 'avg_rtt_ms': 10000, 'type': 'RSSecondary', 'tag': {}}, {'address': 'c:27017', 'avg_rtt_ms': 20000, 'type': 'RSSecondary', 'tag': {}}, {'address': 'a:27017', 'avg_rtt_ms': 30000, 'type': 'RSPrimary', 'tag': {}}, ]}} # Create & populate Topology such that all but one server is too slow. rtt_times = [srv['avg_rtt_ms'] for srv in scenario_def['topology_description']['servers']] min_rtt_idx = rtt_times.index(min(rtt_times)) seeds, hosts = get_addresses( scenario_def["topology_description"]["servers"]) settings = get_topology_settings_dict( heartbeat_frequency=1, local_threshold_ms=1, seeds=seeds, server_selector=selector) topology = Topology(TopologySettings(**settings)) topology.open() for server in scenario_def['topology_description']['servers']: server_description = make_server_description(server, hosts) topology.on_change(server_description) # Invoke server selection and assert no filtering based on latency # prior to custom server selection logic kicking in. server = topology.select_server(ReadPreference.NEAREST) self.assertEqual( len(selector.selection), len(topology.description.server_descriptions())) # Ensure proper filtering based on latency after custom selection. self.assertEqual( server.description.address, seeds[min_rtt_idx]) @client_context.require_replica_set def test_server_selector_bypassed(self): selector = CallCountSelector() scenario_def = { 'topology_description': { 'type': 'ReplicaSetNoPrimary', 'servers': [ {'address': 'b:27017', 'avg_rtt_ms': 10000, 'type': 'RSSecondary', 'tag': {}}, {'address': 'c:27017', 'avg_rtt_ms': 20000, 'type': 'RSSecondary', 'tag': {}}, {'address': 'a:27017', 'avg_rtt_ms': 30000, 'type': 'RSSecondary', 'tag': {}}, ]}} # Create & populate Topology such that no server is writeable. seeds, hosts = get_addresses( scenario_def["topology_description"]["servers"]) settings = get_topology_settings_dict( heartbeat_frequency=1, local_threshold_ms=1, seeds=seeds, server_selector=selector) topology = Topology(TopologySettings(**settings)) topology.open() for server in scenario_def['topology_description']['servers']: server_description = make_server_description(server, hosts) topology.on_change(server_description) # Invoke server selection and assert no calls to our custom selector. with self.assertRaisesRegex( ServerSelectionTimeoutError, 'No primary available for writes'): topology.select_server( writable_server_selector, server_selection_timeout=0.1) self.assertEqual(selector.call_count, 0) if __name__ == "__main__": unittest.main()