v.21.1Improvements

clickhouse-server fails to send close request to ZooKeeper

clickhouse-server didn't send close request to ZooKeeper server. #16837 (alesapin).
Fix ClickHouse server not sending close requests to ZooKeeper server, ensuring proper session termination.

Why it matters

This update resolves an issue where the ClickHouse server did not properly notify the ZooKeeper server of session closures. Properly sending the close request improves resource cleanup, prevents potential session leaks, and enhances stability and reliability of interactions with ZooKeeper.

How to use it

No user action is required; the fix is applied internally in the ClickHouse server. Users benefit automatically from improved ZooKeeper session handling after upgrading to the fixed version.