hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Andrew Purtell (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HBASE-14489) postScannerFilterRow consumes a lot of CPU
Date Fri, 25 Sep 2015 06:21:04 GMT

    [ https://issues.apache.org/jira/browse/HBASE-14489?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14907666#comment-14907666

Andrew Purtell commented on HBASE-14489:

I'll look at the patch when at the desktop tomorrow. 

I do remember microbenchmarking the classloader checks when we added them. You can find the
results on the jira that confirm your suspicions. It was a necessary change but then hook
calls were no longer 'free'. Even a coprocessor that does nothing per hook will accrue that
overhead and early out won't work because something is installed. 

> postScannerFilterRow consumes a lot of CPU
> ------------------------------------------
>                 Key: HBASE-14489
>                 URL: https://issues.apache.org/jira/browse/HBASE-14489
>             Project: HBase
>          Issue Type: Bug
>            Reporter: Lars Hofhansl
>              Labels: performance
>         Attachments: 14489-0.98.txt
> During an unrelated test I found that when scanning a tall table with CQ only and filtering
most results at the server, 50%(!) of time is spend in postScannerFilterRow, even though the
coprocessor does nothing in that hook.
> We need to find a way not to call this hook when not needed, or to question why we have
this hook at all.
> I think [~ram_krish] added the hook (or maybe [~anoop.hbase]). I am also not sure whether
Phoenix uses this hook ([~giacomotaylor]?)

This message was sent by Atlassian JIRA

View raw message