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https://issues.apache.org/jira/browse/CASSANDRA-3578?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13806473#comment-13806473
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Vijay commented on CASSANDRA-3578:
----------------------------------

Other option is replace recycle with discard, we can always create new segments 
and not recycle (instead discard, in sync thread)... we can get rid of the 
header. We still need to skip the commit log recovery, if its corrupted/partial 
write...

> Multithreaded commitlog
> -----------------------
>
>                 Key: CASSANDRA-3578
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-3578
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Jonathan Ellis
>            Assignee: Vijay
>            Priority: Minor
>              Labels: performance
>         Attachments: 0001-CASSANDRA-3578.patch, ComitlogStress.java, 
> Current-CL.png, Multi-Threded-CL.png, parallel_commit_log_2.patch
>
>
> Brian Aker pointed out a while ago that allowing multiple threads to modify 
> the commitlog simultaneously (reserving space for each with a CAS first, the 
> way we do in the SlabAllocator.Region.allocate) can improve performance, 
> since you're not bottlenecking on a single thread to do all the copying and 
> CRC computation.
> Now that we use mmap'd CommitLog segments (CASSANDRA-3411) this becomes 
> doable.
> (moved from CASSANDRA-622, which was getting a bit muddled.)



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