hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jay Booth (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HDFS-918) Use single Selector and small thread pool to replace many instances of BlockSender for reads
Date Thu, 11 Mar 2010 19:36:27 GMT

    [ https://issues.apache.org/jira/browse/HDFS-918?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12844191#action_12844191
] 

Jay Booth commented on HDFS-918:
--------------------------------

I'll enthusiastically cheerlead?  :)

More seriously, I'm willing to put in the work to get everyone to a comfort level with this
patch so it gets committed in some form and we get some wins out of it, but the write path
is more complicated, I don't understand it as well and I'm honestly going to need a little
bit of a break over the summer.  I'd love to help in whatever way I can but I'm probably not
going to have the bandwidth to be the main driver of it in the short term..  I don't fully
grok the write pipeline and the intricacies of append yet, so at the least someone else would
have to be involved. 

> Use single Selector and small thread pool to replace many instances of BlockSender for
reads
> --------------------------------------------------------------------------------------------
>
>                 Key: HDFS-918
>                 URL: https://issues.apache.org/jira/browse/HDFS-918
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: data-node
>            Reporter: Jay Booth
>             Fix For: 0.22.0
>
>         Attachments: hdfs-918-20100201.patch, hdfs-918-20100203.patch, hdfs-918-20100211.patch,
hdfs-918-20100228.patch, hdfs-918-20100309.patch, hdfs-multiplex.patch
>
>
> Currently, on read requests, the DataXCeiver server allocates a new thread per request,
which must allocate its own buffers and leads to higher-than-optimal CPU and memory usage
by the sending threads.  If we had a single selector and a small threadpool to multiplex request
packets, we could theoretically achieve higher performance while taking up fewer resources
and leaving more CPU on datanodes available for mapred, hbase or whatever.  This can be done
without changing any wire protocols.

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


Mime
View raw message