v.21.10Improvements

Improve Remote Query Cancellation for Abnormal Server Termination

Improve remote query cancelation (in case of remote server abnormaly terminated). #27881 (Azat Khuzhin).
Improves remote query cancellation handling when the remote server terminates abnormally.

Why it matters

This feature addresses the issue of hanging or delayed cancellation of queries when a remote ClickHouse server involved in distributed query processing terminates unexpectedly. It ensures that query cancellation commands are properly handled and the client is promptly informed, improving reliability and resource management during remote failures.

How to use it

This improvement is applied automatically in the updated ClickHouse version. Users do not need to enable any additional settings; query cancellation now works more robustly in distributed environments with remote server faults.