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https://issues.apache.org/jira/browse/CASSANDRA-15080?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jon Haddad updated CASSANDRA-15080:
-----------------------------------
    Description: In doing some research for a client on LWTs, I found that once 
we start pushing a node hard enough, with enough LWTs, decompressing the data 
in the paxos table takes up quite a bit of time.  I've attached an SVG flame 
graph showing about 10% of time is spent in LZ4_decompress_fast in queries 
hitting the paxos table.  We should be able to get a nice little performance 
bump from changing this to 4KB chunk length or disabling it completely.  (was: 
In doing some research for a client on LWTs, I found that once we start pushing 
a node hard enough, with enough LWTs, decompressing the data in the paxos table 
takes up quite a bit of time.  I've attached an SVG flame graph showing about 
10% of time is spent in LZ4_decompress_fast in queries hitting the paxos table. 
 We should be able to get a nice little performance bump from changing this to 
4KB chunk length.)
        Summary: Paxos tables should use a 4KB chunk length (or no compression) 
 (was: Paxos tables should use a 4KB chunk length)

> Paxos tables should use a 4KB chunk length (or no compression)
> --------------------------------------------------------------
>
>                 Key: CASSANDRA-15080
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-15080
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Feature/Lightweight Transactions
>            Reporter: Jon Haddad
>            Priority: Normal
>              Labels: performance
>         Attachments: flamegraph-bad-perf.svg
>
>
> In doing some research for a client on LWTs, I found that once we start 
> pushing a node hard enough, with enough LWTs, decompressing the data in the 
> paxos table takes up quite a bit of time.  I've attached an SVG flame graph 
> showing about 10% of time is spent in LZ4_decompress_fast in queries hitting 
> the paxos table.  We should be able to get a nice little performance bump 
> from changing this to 4KB chunk length or disabling it completely.



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