v.20.7Improvement

Keep ZooKeeper Logs Minimal to Prevent Node Growth

Keep smaller amount of logs in ZooKeeper. Avoid excessive growing of ZooKeeper nodes in case of offline replicas when having many servers/tables/inserts. #13100 (alexey-milovidov).
Reduce the number of logs stored in ZooKeeper to prevent excessive growth of ZooKeeper nodes caused by offline replicas in large ClickHouse deployments.

Why it matters

This feature addresses the problem of ZooKeeper node explosion in environments with many servers, tables, and inserts when replicas go offline. By keeping fewer logs in ZooKeeper, it prevents performance degradation and stability issues associated with an overly large ZooKeeper state.

How to use it

This behavior is applied automatically to optimize the amount of logs kept in ZooKeeper. No explicit user action is required to enable this feature, as it is an internal improvement to improve cluster stability and scalability.