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https://issues.apache.org/jira/browse/CASSANDRA-21134?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18058579#comment-18058579
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Dmitry Konstantinov commented on CASSANDRA-21134:
-------------------------------------------------

[~samueldlightfoot] thank you for sharing the preliminary results, it looks 
impressive.
Do you have numbers for direct read + direct write option?
What is the amount of data per select do you have in the test? What 
chunk_length_in_kb value do you use? (in other words: how many disk reads do we 
need per select)

> 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
>  * Support for the compressed path would be most beneficial



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