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https://issues.apache.org/jira/browse/CASSANDRA-16036?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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David Capwell updated CASSANDRA-16036:
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    Attachment: Histogram-15.png

> Add flag to disable chunk cache and disable by default
> ------------------------------------------------------
>
>                 Key: CASSANDRA-16036
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-16036
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Legacy/Local Write-Read Paths
>            Reporter: David Capwell
>            Assignee: David Capwell
>            Priority: Normal
>             Fix For: 4.0-beta
>
>         Attachments: Histogram-11.png, Histogram-15.png, latency_selects.png
>
>
> Chunk cache is enabled by default and doesn’t have a flag to disable without 
> impacting networking.  In performance testing 4.0 against 3.0 I found that 
> reads were slower in 4.0 and after profiling found that the ChunkCache was 
> partially to blame; after disabling the chunk cache, read performance had 
> improved.
> {code}
> 40_w_cc-selects.hdr
> #[Mean    =     11.50063, StdDeviation   =     13.44014]
> #[Max     =    482.41254, Total count    =       316477]
> #[Buckets =           25, SubBuckets     =       262144]
> 40_wo_cc-selects.hdr
> #[Mean    =      9.82115, StdDeviation   =     10.14270]
> #[Max     =    522.36493, Total count    =       317444]
> #[Buckets =           25, SubBuckets     =       262144]
> {code}



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