Hi all,
we are performing an upgrade from mimic to octopus on a test cluster and observe that octopus OSDs are slow to the point that IO is close to impossible. The situation:
- We are running a test workload to simulate a realistic situation.
- We have tested the workload with both, octopus and mimic also under degraded conditions and everything worked well.
- Now we are in the middle of the upgrade and the cluster has to repair missed writes from the time the OSDs of a host were upgraded to octopus.
- Since this upgrade, the performance of the octopus OSDs is extremely poor.
We had ca. 5000/46817475 degraded objects. This is a number that would be repaired within a few seconds or minutes at most under normal conditions. Right now we observe negligible recovery speed. What I see on the hosts is that the mimic OSDs are mostly idle and the octopus OSDs are at 100% CPU. It seems to point to the octopus OSDs being the bottleneck. Network traffic and everything else basically collapsed to 0 after upgrading the first 3 OSDs.
Does anyone have an idea what the bottleneck is and how it can be overcome?
Some diagnostic info:
# ceph status
cluster:
id: bf1f51f5-b381-4cf7-b3db-88d044c1960c
health: HEALTH_WARN
clients are using insecure global_id reclaim
mons are allowing insecure global_id reclaim
3 OSD(s) reporting legacy (not per-pool) BlueStore stats
3 OSD(s) reporting legacy (not per-pool) BlueStore omap usage stats
1 MDSs report slow requests
3 monitors have not enabled msgr2
noout flag(s) set
Degraded data redundancy: 2616/46818177 objects degraded (0.006%), 158 pgs degraded, 42 pgs undersized
5 slow ops, oldest one blocked for 119 sec, daemons [osd.0,osd.2,osd.3,osd.4,osd.6] have slow ops.
services:
mon: 3 daemons, quorum tceph-01,tceph-02,tceph-03 (age 49m)
mgr: tceph-01(active, since 44m), standbys: tceph-03, tceph-02
mds: fs:1 {0=tceph-03=up:active} 2 up:standby
osd: 9 osds: 9 up, 9 in; 42 remapped pgs
flags noout
data:
pools: 4 pools, 321 pgs
objects: 10.42M objects, 352 GiB
usage: 1.7 TiB used, 769 GiB / 2.4 TiB avail
pgs: 2616/46818177 objects degraded (0.006%)
116 active+clean+snaptrim_wait
90 active+recovery_wait+degraded
41 active+recovery_wait+undersized+degraded+remapped
26 active+clean
26 active+recovering+degraded
18 active+clean+snaptrim
2 active+recovery_wait
1 active+recovering
1 active+recovering+undersized+degraded+remapped
io:
client: 18 KiB/s wr, 0 op/s rd, 1 op/s wr
recovery: 0 B/s, 0 objects/s
# ceph versions
{
"mon": {
"ceph version 15.2.17 (8a82819d84cf884bd39c17e3236e0632ac146dc4) octopus (stable)": 3
},
"mgr": {
"ceph version 15.2.17 (8a82819d84cf884bd39c17e3236e0632ac146dc4) octopus (stable)": 3
},
"osd": {
"ceph version 13.2.10 (564bdc4ae87418a232fc901524470e1a0f76d641) mimic (stable)": 6,
"ceph version 15.2.17 (8a82819d84cf884bd39c17e3236e0632ac146dc4) octopus (stable)": 3
},
"mds": {
"ceph version 13.2.10 (564bdc4ae87418a232fc901524470e1a0f76d641) mimic (stable)": 3
},
"overall": {
"ceph version 13.2.10 (564bdc4ae87418a232fc901524470e1a0f76d641) mimic (stable)": 9,
"ceph version 15.2.17 (8a82819d84cf884bd39c17e3236e0632ac146dc4) octopus (stable)": 9
}
}
# ceph osd tree
ID CLASS WEIGHT TYPE NAME STATUS REWEIGHT PRI-AFF
-1 2.44798 root default
-3 0.81599 host tceph-01
0 hdd 0.27199 osd.0 up 0.84999 1.00000 <- octopus
3 hdd 0.27199 osd.3 up 0.89999 1.00000 <- octopus
6 hdd 0.27199 osd.6 up 0.95000 1.00000 <- octopus
-5 0.81599 host tceph-02
2 hdd 0.27199 osd.2 up 1.00000 1.00000 <- mimic
5 hdd 0.27199 osd.5 up 0.84999 1.00000 <- mimic
7 hdd 0.27199 osd.7 up 0.95000 1.00000 <- mimic
-7 0.81599 host tceph-03
1 hdd 0.27199 osd.1 up 0.95000 1.00000 <- mimic
4 hdd 0.27199 osd.4 up 0.89999 1.00000 <- mimic
8 hdd 0.27199 osd.8 up 1.00000 1.00000 <- mimic
# ceph config dump
WHO MASK LEVEL OPTION VALUE RO
global unknown bluefs_preextend_wal_files true *
global advanced osd_map_message_max_bytes 16384
global advanced osd_op_queue wpq *
global advanced osd_op_queue_cut_off high *
mon advanced mon_sync_max_payload_size 4096
mgr unknown mgr/dashboard/password $2b$12$DYJkkmdzaVtFR.GWYhTT.ezwGgNLi1BL7meoY.z8ya4PP9MfZIPqu *
mgr unknown mgr/dashboard/username rit *
osd dev bluestore_fsck_quick_fix_on_mount false
osd class:hdd advanced osd_max_backfills 18
osd class:hdd dev osd_memory_cache_min 805306368
osd class:hdd basic osd_memory_target 1611661312
osd class:hdd advanced osd_recovery_max_active 8
osd class:hdd advanced osd_recovery_sleep 0.050000
osd class:hdd advanced osd_snap_trim_sleep 0.100000
mds basic client_cache_size 8192
mds advanced mds_bal_fragment_size_max 500000
mds basic mds_cache_memory_limit 17179869184
mds advanced mds_cache_reservation 0.500000
mds advanced mds_max_caps_per_client 65536
mds advanced mds_min_caps_per_client 4096
mds advanced mds_recall_max_caps 16384
mds advanced mds_session_blacklist_on_timeout false
# ceph config get osd.0 bluefs_buffered_io
true
Thanks for any pointers,
=================
Frank Schilder
AIT Risø Campus
Bygning 109, rum S14
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