v.21.11Improvements

Forbid Cleaning of Active Mutation/Merge tmp Directories

Official CH changelog text
Forbid cleaning of tmp directories that can be used by an active mutation/merge if mutation/merge is extraordinarily long. #28760 (Azat Khuzhin).
Prevent cleaning of temporary directories used by active mutations or merges when these operations take an unusually long time.

Why it matters

This feature addresses the problem where long-running mutations or merges could have their temporary directories cleaned up prematurely, potentially causing errors or data corruption. By forbidding cleanup of these tmp directories during extended operations, it ensures stability and correctness of mutation and merge processes.

How to use it

The feature is applied automatically by the system to protect temporary directories associated with active long-running mutations or merges. No user intervention is required to enable this safeguard.

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