[
https://issues.apache.org/jira/browse/CASSANDRA-3610?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13175014#comment-13175014
]
Vijay commented on CASSANDRA-3610:
----------------------------------
Fields:
1 -> bytes sent to checksum
2 -> Mb/s (trials * size / 1024.0 / 1024.0) by pure java implementation
3 -> Mb/s by Native CRC
5 -> Pure Jave Random bytes from and till
6 -> Pure Java Mb/S
8 -> Native Random bytes from and till
9 -> Native Java Mb/S
Hope that makes sense... i should have separated the two tests random and
constant byte test.
> Checksum improvement for CompressedRandomAccessReader
> -----------------------------------------------------
>
> Key: CASSANDRA-3610
> URL: https://issues.apache.org/jira/browse/CASSANDRA-3610
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Affects Versions: 1.1
> Environment: JVM
> Reporter: Vijay
> Assignee: Vijay
> Priority: Minor
> Fix For: 1.1
>
> Attachments: 0001-use-pure-java-CRC32-v2.patch,
> 0001-use-pure-java-CRC32.patch
>
>
> When compression is on, Currently we see checksum taking up about 40% of the
> CPU more than snappy library.
> Looks like hadoop solved it by implementing their own checksum, we can either
> use it or implement something like that.
> http://images.slidesharecdn.com/1toddlipconyanpeichen-cloudera-hadoopandperformance-final-111110132228-phpapp01-slide-15-768.jpg?1321043717
> in our test env it provided 50% improvement over native implementation which
> uses jni to call the OS.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
