[jira] [Commented] (CASSANDRA-20129) Restore optimization in MultiCBuilder around building one clustering

["Caleb Rackliffe (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CASSANDRA-20129?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17903743#comment-17903743 ] 

Caleb Rackliffe commented on CASSANDRA-20129:
---------------------------------------------

CC [~e.dimitrova]

> Restore optimization in MultiCBuilder around building one clustering
> --------------------------------------------------------------------
>
>                 Key: CASSANDRA-20129
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-20129
>             Project: Apache Cassandra
>          Issue Type: Bug
>          Components: Legacy/Local Write-Read Paths
>            Reporter: Caleb Rackliffe
>            Assignee: Caleb Rackliffe
>            Priority: Normal
>
> Back in CASSANDRA-10409, we optimized the single clustering case for {{MultiCBuilder}} to produce less garbage. In CASSANDRA-19341, we de-facto removed that optimization, and I'm seeing increased allocations in trunk, specifically at least double the number of {{BTree}} builders. In the write-heavy workload I'm profiling, this jumps up to become the most common TLAB allocation. I'm attaching JFR screenshots from 4.1 and trunk that show the codepaths that touch this on both versions. We should consider reintroducing something like the old {{OneClusteringBuilder}}.
> I used {{WriteBench}} to explore things here, mostly w/ the TRUNCATE {{EndOp}}, and made sure commitlog writes, view updates, and {{CassandraTableWriteHandler}} tracing were disabled to reduce the noise.
>  
> [~blerer]



--
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