hbase-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jean-Daniel Cryans (JIRA)" <j...@apache.org>
Subject [jira] Updated: (HBASE-887) Fix a hotspot in scanners
Date Wed, 17 Sep 2008 19:27:44 GMT

     [ https://issues.apache.org/jira/browse/HBASE-887?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel

Jean-Daniel Cryans updated HBASE-887:

    Attachment: hbase-887-v1.patch

This patch fixes the hotspot. When running the PE with only 1 row prefetched (so the same
as usual), I got these numbers:

bq. Finished scan in 84713ms at offset 0 for 1048576 rows

With my patch in place and a configured 2000 rows of caching, I got:

bq. Finished scan in 34754ms at offset 0 for 1048576 rows

Passes the tests. Please try it and review. Maybe the default hbase.client.scanner.caching
should be 1 to be sure and a bigger number for MR jobs?

> Fix a hotspot in scanners
> -------------------------
>                 Key: HBASE-887
>                 URL: https://issues.apache.org/jira/browse/HBASE-887
>             Project: Hadoop HBase
>          Issue Type: Improvement
>          Components: client, regionserver
>            Reporter: Jean-Daniel Cryans
>            Assignee: Jean-Daniel Cryans
>             Fix For: 0.19.0
>         Attachments: hbase-887-v1.patch
> When scanning, we do a lot of RPCs and this has a huge performance hit. I propose that
we add a way to fetch more rows during next() and put them in cache. This should be configurable.

This message is automatically generated by JIRA.
You can reply to this email to add a comment to the issue online.

View raw message