qa: Reduce number of osd threads when using compression

Smithi nodes used by teuthology tests have 8 CPU cores and typically run
4 OSD processes. When bluestore software compression is enabled the size
of the OSD thread pool needs to be reduced to 2 threads per OSD because
these threads can easily use 100% of a core. This avoids excessive
amounts of context switches, which leads to OSD threads timing out,
which causes the OSD to drop heartbeat pings and for the monitor to
temporarily mark it down. In extreme cases this can lead to PGs getting
stuck in repeated loops of peering until the teuthology test times out.

Context switches happen oppurtunistically at the end of system calls
so functions with lots of logging are some of the worst affected.

Fixes: https://tracker.ceph.com/issues/72879
Signed-off-by: Bill Scales <bill_scales@uk.ibm.com>
This commit is contained in:
Bill Scales 2025-11-21 10:06:22 +00:00
parent 3693e835b0
commit ea9588e330
12 changed files with 24 additions and 0 deletions

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@ -5,3 +5,5 @@ overrides:
bluestore compression mode: aggressive
bluestore compression algorithm: lz4
osd_mclock_skip_benchmark: true #new recompression makes us fail the test
osd op num threads per shard: 2 #https://tracker.ceph.com/issues/72879
osd op num shards: 1

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@ -5,3 +5,5 @@ overrides:
bluestore compression mode: aggressive
bluestore compression algorithm: snappy
osd_mclock_skip_benchmark: true #new recompression makes us fail the test
osd op num threads per shard: 2 #https://tracker.ceph.com/issues/72879
osd op num shards: 1

View File

@ -5,3 +5,5 @@ overrides:
bluestore compression mode: aggressive
bluestore compression algorithm: zlib
osd_mclock_skip_benchmark: true #new recompression makes us fail the test
osd op num threads per shard: 2 #https://tracker.ceph.com/issues/72879
osd op num shards: 1

View File

@ -5,3 +5,5 @@ overrides:
bluestore compression mode: aggressive
bluestore compression algorithm: zstd
osd_mclock_skip_benchmark: true #new recompression makes us fail the test
osd op num threads per shard: 2 #https://tracker.ceph.com/issues/72879
osd op num shards: 1

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@ -4,3 +4,5 @@ overrides:
osd:
bluestore compression mode: aggressive
bluestore compression algorithm: lz4
osd op num threads per shard: 2 #https://tracker.ceph.com/issues/72879
osd op num shards: 1

View File

@ -4,3 +4,5 @@ overrides:
osd:
bluestore compression mode: aggressive
bluestore compression algorithm: snappy
osd op num threads per shard: 2 #https://tracker.ceph.com/issues/72879
osd op num shards: 1

View File

@ -4,3 +4,5 @@ overrides:
osd:
bluestore compression mode: aggressive
bluestore compression algorithm: zlib
osd op num threads per shard: 2 #https://tracker.ceph.com/issues/72879
osd op num shards: 1

View File

@ -4,3 +4,5 @@ overrides:
osd:
bluestore compression mode: aggressive
bluestore compression algorithm: zstd
osd op num threads per shard: 2 #https://tracker.ceph.com/issues/72879
osd op num shards: 1

View File

@ -5,3 +5,5 @@ overrides:
bluestore compression mode: aggressive
bluestore compression algorithm: lz4
osd_mclock_skip_benchmark: true #new recompression makes us fail the test
osd op num threads per shard: 2 #https://tracker.ceph.com/issues/72879
osd op num shards: 1

View File

@ -5,3 +5,5 @@ overrides:
bluestore compression mode: aggressive
bluestore compression algorithm: snappy
osd_mclock_skip_benchmark: true #new recompression makes us fail the test
osd op num threads per shard: 2 #https://tracker.ceph.com/issues/72879
osd op num shards: 1

View File

@ -5,3 +5,5 @@ overrides:
bluestore compression mode: aggressive
bluestore compression algorithm: zlib
osd_mclock_skip_benchmark: true #new recompression makes us fail the test
osd op num threads per shard: 2 #https://tracker.ceph.com/issues/72879
osd op num shards: 1

View File

@ -5,3 +5,5 @@ overrides:
bluestore compression mode: aggressive
bluestore compression algorithm: zstd
osd_mclock_skip_benchmark: true #new recompression makes us fail the test
osd op num threads per shard: 2 #https://tracker.ceph.com/issues/72879
osd op num shards: 1