Restore socket timeout after connection + add changelog

Author: NoahStapp

doc/changelog.rst

@@ -8,6 +8,23 @@ PyMongo 4.14 brings a number of changes including:
 - Added :attr:`bson.codec_options.TypeRegistry.codecs` and :attr:`bson.codec_options.TypeRegistry.fallback_encoder` properties
   to allow users to directly access the type codecs and fallback encoder for a given :class:`bson.codec_options.TypeRegistry`.
 
+Changes in Version 4.13.2 (2025/06/17)
+--------------------------------------
+
+Version 4.13.2 is a bug fix release.
+
+- Fixed a bug where ``AsyncMongoClient`` would block the event loop while creating new connections,
+  potentially significantly increasing latency for ongoing operations.
+
+Issues Resolved
+...............
+
+See the `PyMongo 4.13.2 release notes in JIRA`_ for the list of resolved issues
+in this release.
+
+.. _PyMongo 4.13.2 release notes in JIRA: https://jira.mongodb.org/secure/ReleaseNote.jspa?projectId=10004&version=43937
+
+
 Changes in Version 4.13.1 (2025/06/10)
 --------------------------------------
 

pymongo/pool_shared.py

@@ -244,10 +244,12 @@ async def _async_create_connection(address: _Address, options: PoolOptions) -> s
                 raise socket.timeout("timed out")
             sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, True)
             _set_keepalive_times(sock)
+            # Socket needs to be non-blocking during connection to not block the event loop
             sock.setblocking(False)
             await asyncio.wait_for(
                 asyncio.get_running_loop().sock_connect(sock, sa), timeout=timeout
             )
+            sock.settimeout(timeout)
             return sock
         except asyncio.TimeoutError as e:
             sock.close()