Hi Mark, In v17.2.7 we enabled a feature that automatically performs a compaction >> if too many tombstones are present during iteration in RocksDB. It >> might be worth upgrading to see if it helps (you might have to try >> tweaking the settings if the defaults aren't helping enough). The PR is >> here: >> >> https://github.com/ceph/ceph/pull/50893 > > we've upgraded Ceph to v17.2.7 yesterday. Unfortunately I still see growing latency on OSDs hosting index pool. Will try to tune rocksdb_cf_compact_on_deletion options as you suggested.
I've started with decreasing deletion_trigger from 16384 to 512 with: # ceph tell 'osd.*' injectargs '--rocksdb_cf_compact_on_deletion_trigger 512' At first glance - nothing has changed per OSD latency graphs. I've tried to decrease it to 32 deletions per window on a single OSD where I see increasing latency to force compactions, but per graphs nothing has changed after approx 40 minutes. # ceph tell 'osd.435' injectargs '--rocksdb_cf_compact_on_deletion_trigger 32' Didn't touch rocksdb_cf_compact_on_deletion_sliding_window yet, it is set with default 32768 entries. Do you know if it rocksdb_cf_compact_on_deletion_trigger and rocksdb_cf_compact_on_deletion_sliding_window can be changed in runtime without OSD restart? -- Thank you, Roman _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-le...@ceph.io
