Ceph Quincy MDS Standby-Replay Memory Leak

Overview

The Ceph MDS standby-replay daemon is affected by a now-fixed memory leak bug that causes gradually increasing memory consumption¹.

This is fixed in Ceph Versions 17.2.8² and 18.2.4³.

Workarounds

1. Memory-Based Restart:

   • Monitor MDS memory usage
   • Restart the MDS when it reaches a specific memory threshold
   • Can be automated using earlyoom

2. Disable Standby-Replay:

ceph fs set <fsname> allow_standby_replay false

Bug Reference

This issue is tracked in Ceph’s issue tracker¹. The bug affects multiple versions of Ceph and requires either implementing one of the workarounds or upgrading to a version with the fix.

Footnotes

1. Ceph Issue #48673 - MDS Memory Leak ↩ ↩²

2. https://tracker.ceph.com/issues/63675 ↩

3. https://tracker.ceph.com/issues/63676 ↩