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https://issues.apache.org/jira/browse/CASSANDRA-16036?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17186039#comment-17186039
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David Capwell commented on CASSANDRA-16036:
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Thanks jon, will update conf/cassandra.yaml.
bq. work out how to use their memory budget.
Yeah, this is why I still lean to this default. I have not found a use case
which benefits from chunk cache and find some use cases which are roughly equal
with and without, so favor disabling in these cases to save memory (a much
limited resource in production).
> 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: async-profile.collapsed.svg,
> clustering-in-clause_latency_selects_baseline.png,
> clustering-in-clause_latency_selects_baseline_attempt3.png,
> clustering-in-clause_latency_under90_selects_baseline.png,
> clustering-in-clause_latency_under90_selects_baseline_attempt3.png,
> clustering-slice_latency_selects_baseline.png,
> clustering-slice_latency_under90_selects_baseline.png,
> medium-blobs_latency_selects_baseline.png,
> medium-blobs_latency_under90_selects_baseline.png,
> partition-single-row-read_latency_selects_baseline.png,
> partition-single-row-read_latency_under90_selects_baseline.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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