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Posted to commits@cassandra.apache.org by "David Capwell (Jira)" <ji...@apache.org> on 2020/08/07 05:14:00 UTC
[jira] [Updated] (CASSANDRA-16036) Add flag to disable chunk cache
and disable by defaul
[ https://issues.apache.org/jira/browse/CASSANDRA-16036?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
David Capwell updated CASSANDRA-16036:
--------------------------------------
Description:
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}
was:
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.
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]
> Add flag to disable chunk cache and disable by defaul
> -----------------------------------------------------
>
> 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
>
>
> 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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