PYTHON-4021 - Publish TopologyDescriptionChangedEvent on topology close (mongodb#1762)

Author: NoahStapp

pymongo/asynchronous/topology.py

@@ -664,9 +664,31 @@ async def close(self) -> None:
  # Publish only after releasing the lock.
  if self._publish_tp:
  assert self._events is not None
+ old_td = self._description
+ self._description = TopologyDescription(
+ TOPOLOGY_TYPE.Unknown,
+ {},
+ self._description.replica_set_name,
+ self._description.max_set_version,
+ self._description.max_election_id,
+ self._description._topology_settings,
+ )
+ self._events.put(
+ (
+ self._listeners.publish_topology_description_changed,
+ (
+ old_td,
+ self._description,
+ self._topology_id,
+ ),
+ )
+ )
  self._events.put((self._listeners.publish_topology_closed, (self._topology_id,)))
  if self._publish_server or self._publish_tp:
+ # Make sure the events executor thread is fully closed before publishing the remaining events
  self.__events_executor.close()
+ self.__events_executor.join(1)
+ process_events_queue(weakref.ref(self._events)) # type: ignore[arg-type]
 
  @property
  def description(self) -> TopologyDescription:

pymongo/synchronous/topology.py

@@ -662,9 +662,31 @@ def close(self) -> None:
  # Publish only after releasing the lock.
  if self._publish_tp:
  assert self._events is not None
+ old_td = self._description
+ self._description = TopologyDescription(
+ TOPOLOGY_TYPE.Unknown,
+ {},
+ self._description.replica_set_name,
+ self._description.max_set_version,
+ self._description.max_election_id,
+ self._description._topology_settings,
+ )
+ self._events.put(
+ (
+ self._listeners.publish_topology_description_changed,
+ (
+ old_td,
+ self._description,
+ self._topology_id,
+ ),
+ )
+ )
  self._events.put((self._listeners.publish_topology_closed, (self._topology_id,)))
  if self._publish_server or self._publish_tp:
+ # Make sure the events executor thread is fully closed before publishing the remaining events
  self.__events_executor.close()
+ self.__events_executor.join(1)
+ process_events_queue(weakref.ref(self._events)) # type: ignore[arg-type]
 
  @property
  def description(self) -> TopologyDescription:

test/discovery_and_monitoring/rs/compatible.json

@@ -16,7 +16,7 @@
  "b:27017"
  ],
  "minWireVersion": 0,
- "maxWireVersion": 6
+ "maxWireVersion": 21
  }
  ],
  [

test/discovery_and_monitoring/rs/compatible_unknown.json

@@ -16,7 +16,7 @@
  "b:27017"
  ],
  "minWireVersion": 0,
- "maxWireVersion": 6
+ "maxWireVersion": 21
  }
  ]
  ],

test/discovery_and_monitoring/sharded/compatible.json

@@ -23,7 +23,7 @@
  "isWritablePrimary": true,
  "msg": "isdbgrid",
  "minWireVersion": 0,
- "maxWireVersion": 6
+ "maxWireVersion": 21
  }
  ]
  ],

test/discovery_and_monitoring/single/compatible.json

@@ -11,7 +11,7 @@
  "helloOk": true,
  "isWritablePrimary": true,
  "minWireVersion": 0,
- "maxWireVersion": 6
+ "maxWireVersion": 21
  }
  ]
  ],

test/discovery_and_monitoring/single/too_old_then_upgraded.json

@@ -1,5 +1,5 @@
 {
- "description": "Standalone with default maxWireVersion of 0 is upgraded to one with maxWireVersion 6",
+ "description": "Standalone with default maxWireVersion of 0 is upgraded to one with maxWireVersion 21",
  "uri": "mongodb://a",
  "phases": [
  {
@@ -35,7 +35,7 @@
  "helloOk": true,
  "isWritablePrimary": true,
  "minWireVersion": 0,
- "maxWireVersion": 6
+ "maxWireVersion": 21
  }
  ]
  ],