Re: [ceph-users] Seemingly unbounded osd_snap keys in monstore. Normal? Expected?
Hi, On Mon, 23 Sep 2019, Koebbe, Brian wrote:
Our cluster has a little over 100 RBDs. Each RBD is snapshotted with a typical "frequently", hourly, daily, monthly type of schedule. A while back a 4th monitor was temporarily added to the cluster that took hours to synchronize with the other 3. While trying to figure out why that addition took so long, we discovered that our monitors have what seems like a really large number of osd_snap keys:
ceph-monstore-tool /var/lib/ceph/mon/xxxxxx dump-keys |awk '{print $1}'|uniq -c 153 auth 2 config 10 health 1441 logm 3 mdsmap 313 mgr 1 mgr_command_descs 3 mgr_metadata 163 mgrstat 1 mkfs 323 mon_config_key 1 mon_sync 6 monitor 1 monitor_store 32 monmap 120 osd_metadata 1 osd_pg_creating 5818618 osd_snap 41338 osdmap 754 paxos
A few questions:
Could this be the cause of the slow addition/synchronization?
Probably!
Is what looks like an unbounded number of osd_snaps expected?
Maybe. Can you send me the output of 'ceph osd dump'? Also, if you don't mind doing the dump above and grepping out just the osd_snap keys, so I can see what they look like and if they match the osd map contents? Thanks! sage
If trimming/compacting them would help, how would one do that?
Thanks, Brian
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Thanks Sage! ceph osd dump: https://pastebin.com/raw/zLPz9DQg ceph-monstore-tool /var/lib/ceph/mon/ceph-ufm03 dump-keys |grep osd_snap| cut -c-29 |uniq -c 2 osd_snap / purged_snap_10_000 1 osd_snap / purged_snap_12_000 75 osd_snap / purged_snap_13_000 4 osd_snap / purged_snap_14_000 778106 osd_snap / purged_snap_15_000 861 osd_snap / purged_snap_1_0000 323 osd_snap / purged_snap_4_0000 88 osd_snap / purged_snap_5_0000 2 osd_snap / purged_snap_7_0000 2 osd_snap / purged_snap_8_0000 2 osd_snap / removed_epoch_10_0 1 osd_snap / removed_epoch_12_0 75 osd_snap / removed_epoch_13_0 4 osd_snap / removed_epoch_14_0 2316417 osd_snap / removed_epoch_15_0 970 osd_snap / removed_epoch_1_00 324 osd_snap / removed_epoch_4_00 89 osd_snap / removed_epoch_5_00 2 osd_snap / removed_epoch_7_00 2 osd_snap / removed_epoch_8_00 2 osd_snap / removed_snap_10_00 1 osd_snap / removed_snap_12_00 75 osd_snap / removed_snap_13_00 4 osd_snap / removed_snap_14_00 2720849 osd_snap / removed_snap_15_00 1161 osd_snap / removed_snap_1_000 379 osd_snap / removed_snap_4_000 89 osd_snap / removed_snap_5_000 2 osd_snap / removed_snap_7_000 2 osd_snap / removed_snap_8_000 ________________________________ From: Sage Weil <sage@newdream.net> Sent: Monday, September 23, 2019 9:41 AM To: Koebbe, Brian <koebbe@wustl.edu> Cc: ceph-users@ceph.io <ceph-users@ceph.io>; dev@ceph.io <dev@ceph.io> Subject: Re: [ceph-users] Seemingly unbounded osd_snap keys in monstore. Normal? Expected? Hi, On Mon, 23 Sep 2019, Koebbe, Brian wrote:
Our cluster has a little over 100 RBDs. Each RBD is snapshotted with a typical "frequently", hourly, daily, monthly type of schedule. A while back a 4th monitor was temporarily added to the cluster that took hours to synchronize with the other 3. While trying to figure out why that addition took so long, we discovered that our monitors have what seems like a really large number of osd_snap keys:
ceph-monstore-tool /var/lib/ceph/mon/xxxxxx dump-keys |awk '{print $1}'|uniq -c 153 auth 2 config 10 health 1441 logm 3 mdsmap 313 mgr 1 mgr_command_descs 3 mgr_metadata 163 mgrstat 1 mkfs 323 mon_config_key 1 mon_sync 6 monitor 1 monitor_store 32 monmap 120 osd_metadata 1 osd_pg_creating 5818618 osd_snap 41338 osdmap 754 paxos
A few questions:
Could this be the cause of the slow addition/synchronization?
Probably!
Is what looks like an unbounded number of osd_snaps expected?
Maybe. Can you send me the output of 'ceph osd dump'? Also, if you don't mind doing the dump above and grepping out just the osd_snap keys, so I can see what they look like and if they match the osd map contents? Thanks! sage
If trimming/compacting them would help, how would one do that?
Thanks, Brian
________________________________ The materials in this message are private and may contain Protected Healthcare Information or other information of a sensitive nature. If you are not the intended recipient, be advised that any unauthorized use, disclosure, copying or the taking of any action in reliance on the contents of this information is strictly prohibited. If you have received this email in error, please immediately notify the sender via telephone or return mail.
________________________________ The materials in this message are private and may contain Protected Healthcare Information or other information of a sensitive nature. If you are not the intended recipient, be advised that any unauthorized use, disclosure, copying or the taking of any action in reliance on the contents of this information is strictly prohibited. If you have received this email in error, please immediately notify the sender via telephone or return mail.
participants (2)
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Koebbe, Brian
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Sage Weil