Jon Haddad created CASSANDRA-20085:
--------------------------------------
Summary: move compaction writer to separate thread
Key: CASSANDRA-20085
URL: https://issues.apache.org/jira/browse/CASSANDRA-20085
Project: Cassandra
Issue Type: Improvement
Reporter: Jon Haddad
Attachments: image-2024-11-15-09-45-51-450.png,
image-2024-11-15-09-50-41-854.png
I'm examining a 5.0 cluster, mostly default settings except these overrides:
{noformat}
cluster_name: "rokt-density"
num_tokens: 4
concurrent_reads: 64
concurrent_writes: 64
trickle_fsync: true
endpoint_snitch: "Ec2Snitch"
compaction_throughput: 0MiB/s
key_cache_migrate_during_compaction: false
{noformat}
Here's a flame graph of compaction taken with these settings:
{noformat}
asprof -e wall -X '*Unsafe.park*' -X '*Native.epollWait' -I '*compaction*'
{noformat}
!image-2024-11-15-09-50-41-854.png|thumbnail!
and in reverse:
!image-2024-11-15-09-45-51-450.png|thumbnail!
It's clear we can get an easy win by moving the writing portion of compaction
to a dedicated thread (ExecutorService.newSingleThreadExecutor() ?), instead of
blocking in the same one. For this use case, it would improve compaction
throughput by about 2x.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
