[ 
https://issues.apache.org/jira/browse/HBASE-5778?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Jean-Daniel Cryans updated HBASE-5778:
--------------------------------------

    Attachment: HBASE-5778-trunk-v6.patch
                HBASE-5778-0.94-v6.patch

Patch I want to commit to 0.94, I refreshed it again and fixed one other thing 
regarding the ReplicationSource.currentSize attribute because it wasn't set 
properly and refreshed.

The patch for trunk enables HLog compression by default and removes the 
compression-related tests. I'm currently running all the tests.
                
> Turn on WAL compression by default
> ----------------------------------
>
>                 Key: HBASE-5778
>                 URL: https://issues.apache.org/jira/browse/HBASE-5778
>             Project: HBase
>          Issue Type: Improvement
>            Reporter: Jean-Daniel Cryans
>            Assignee: Jean-Daniel Cryans
>            Priority: Blocker
>             Fix For: 0.96.0
>
>         Attachments: 5778.addendum, 5778-addendum.txt, HBASE-5778-0.94.patch, 
> HBASE-5778-0.94-v2.patch, HBASE-5778-0.94-v3.patch, HBASE-5778-0.94-v4.patch, 
> HBASE-5778-0.94-v5.patch, HBASE-5778-0.94-v6.patch, HBASE-5778.patch, 
> HBASE-5778-trunk-v6.patch
>
>
> I ran some tests to verify if WAL compression should be turned on by default.
> For a use case where it's not very useful (values two order of magnitude 
> bigger than the keys), the insert time wasn't different and the CPU usage 15% 
> higher (150% CPU usage VS 130% when not compressing the WAL).
> When values are smaller than the keys, I saw a 38% improvement for the insert 
> run time and CPU usage was 33% higher (600% CPU usage VS 450%). I'm not sure 
> WAL compression accounts for all the additional CPU usage, it might just be 
> that we're able to insert faster and we spend more time in the MemStore per 
> second (because our MemStores are bad when they contain tens of thousands of 
> values).
> Those are two extremes, but it shows that for the price of some CPU we can 
> save a lot. My machines have 2 quads with HT, so I still had a lot of idle 
> CPUs.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to