I also tried setting RocksDB compression options and deploying a new monitor. The monitor started with no RocksDB compression again. Ceph monitors seem to ignore mon_rocksdb_options set at runtime, at mon start and at mon deploy. How can I enable RocksDB compression in Ceph monitors? Any input from anyone, please? /Z On Fri, 13 Oct 2023 at 23:01, Zakhar Kirpichenko <zakhar@xxxxxxxxx> wrote: > Hi, > > I'm still trying to fight large Ceph monitor writes. One option I > considered is enabling RocksDB compression, as our nodes have more than > sufficient RAM and CPU. Unfortunately, monitors seem to completely ignore > the compression setting: > > I tried: > > - setting ceph config set mon.ceph05 mon_rocksdb_options > "write_buffer_size=33554432,compression=kLZ4Compression,level_compaction_dynamic_level_bytes=true", > restarting the test monitor. The monitor started with no RocksDB > compression: > > debug 2023-10-13T19:47:00.403+0000 7f1cd967a880 4 rocksdb: Compression > algorithms supported: > debug 2023-10-13T19:47:00.403+0000 7f1cd967a880 4 rocksdb: > kZSTDNotFinalCompression supported: 0 > debug 2023-10-13T19:47:00.403+0000 7f1cd967a880 4 rocksdb: > kXpressCompression supported: 0 > debug 2023-10-13T19:47:00.403+0000 7f1cd967a880 4 rocksdb: > kLZ4HCCompression supported: 1 > debug 2023-10-13T19:47:00.403+0000 7f1cd967a880 4 rocksdb: > kLZ4Compression supported: 1 > debug 2023-10-13T19:47:00.403+0000 7f1cd967a880 4 rocksdb: > kBZip2Compression supported: 0 > debug 2023-10-13T19:47:00.403+0000 7f1cd967a880 4 rocksdb: > kZlibCompression supported: 1 > debug 2023-10-13T19:47:00.403+0000 7f1cd967a880 4 rocksdb: > kSnappyCompression supported: 1 > ... > debug 2023-10-13T19:47:00.403+0000 7f1cd967a880 4 rocksdb: > Options.compression: NoCompression > debug 2023-10-13T19:47:00.403+0000 7f1cd967a880 4 rocksdb: > Options.bottommost_compression: Disabled > > - setting ceph config set mon mon_rocksdb_options > "write_buffer_size=33554432,compression=kLZ4Compression,level_compaction_dynamic_level_bytes=true", > restarting the test monitor. The monitor started with no RocksDB > compression, the same way as above. > > In each case config options were correctly set and readable with config > get. I also found a suggestion in ceph-users ( > https://lists.ceph.io/hyperkitty/list/ceph-users@xxxxxxx/message/KJM232IHN7FKYI5LODUREN7SVO45BL42/) > to set compression in a similar manner. Unfortunately, these options appear > to be ignored. > > How can I enable RocksDB compression in Ceph monitors? > > I would very much appreciate your advices and comments. > > Best regards, > Zakhar > > > _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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