[
https://issues.apache.org/jira/browse/CASSANDRA-6809?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14298891#comment-14298891
]
Branimir Lambov commented on CASSANDRA-6809:
--------------------------------------------
Added a stress test exercising all log options to the long test suite and fixed
several issues:
- Initialization could fail with NPE or similar as some threads started within
the CommitLog constructor could use fields which weren't initialized yet.
- Made sure the length of sync sections is precise; replay could read beyond
the end of the file or read stale mutations from reused compressed buffers when
the length is not precise.
- Made sure completed segment files are always closed.
> Compressed Commit Log
> ---------------------
>
> Key: CASSANDRA-6809
> URL: https://issues.apache.org/jira/browse/CASSANDRA-6809
> Project: Cassandra
> Issue Type: Improvement
> Reporter: Benedict
> Assignee: Branimir Lambov
> Priority: Minor
> Labels: performance
> Fix For: 3.0
>
> Attachments: ComitLogStress.java, logtest.txt
>
>
> It seems an unnecessary oversight that we don't compress the commit log.
> Doing so should improve throughput, but some care will need to be taken to
> ensure we use as much of a segment as possible. I propose decoupling the
> writing of the records from the segments. Basically write into a (queue of)
> DirectByteBuffer, and have the sync thread compress, say, ~64K chunks every X
> MB written to the CL (where X is ordinarily CLS size), and then pack as many
> of the compressed chunks into a CLS as possible.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
