[jira] [Commented] (CASSANDRA-21134) Direct IO support for compaction writes

["Sam Lightfoot (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CASSANDRA-21134?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18063039#comment-18063039 ] 

Sam Lightfoot commented on CASSANDRA-21134:
-------------------------------------------

Added both-DIO results. Key is that block device contention offsets gains from reduction in memory stalls. Next set of results to obtain are for throttled compaction, which are more production realistic.

[~dnk] 

> Direct IO support for compaction writes
> ---------------------------------------
>
>                 Key: CASSANDRA-21134
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-21134
>             Project: Apache Cassandra
>          Issue Type: Improvement
>          Components: Local/Compaction
>            Reporter: Sam Lightfoot
>            Assignee: Sam Lightfoot
>            Priority: Normal
>             Fix For: 5.x
>
>         Attachments: image-2026-02-11-17-22-58-361.png, image-2026-02-11-17-25-58-329.png
>
>
> Follow-up from the implementation for compaction reads (CASSANDRA-19987)
> Notable points
>  * Update the start-up check that impacts DIO writes ({_}checkKernelBug1057843{_})
>  * RocksDB uses 1 MB flush buffer. This should be configurable and performance tested (256KB vs 1MB)
>  * Introduce compaction_write_disk_access_mode / backgroud_write_disk_access_mode
>  * Support for the compressed path would be most beneficial



--
This message was sent by Atlassian Jira
(v8.20.10#820010)

---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscribe@cassandra.apache.org
For additional commands, e-mail: commits-help@cassandra.apache.org