2025-09-10: GitLab 500 errors and slowness

GitLab 500 errors and slowness (Severity 2 (High))

Problem: GitLab returned 500 and 502 errors and became slow, especially for users of gitlab-org repositories, due to overloaded system resources.

Impact: Users interacting with gitlab-org repositories experienced 500 and 502 errors and significant performance slowness. This disrupted internal teams and external customers who rely on gitlab-org for CI/CD templates and related workflows.

Causes: Excessive concurrent ‘git repack’ processes were triggered by GitLab housekeeping operations on the gitlab-org repository, leading to high memory usage and service errors.

Response strategy: We performed targeted termination of high-memory ‘git pack-objects’ processes and disabled a feature flag to stop new repacks. Cleanup of lingering processes restored memory to normal levels, and the system is now stable under heightened monitoring. We are collaborating with the Git and Gitaly teams to investigate why housekeeping triggered so many repacks.

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This ticket was created to track INC-3842, by incident.io 🔥