You are viewing a plain text version of this content. The canonical link for it is here.

Posted to common-dev@hadoop.apache.org by "Zheng Shao (JIRA)" <ji...@apache.org> on 2009/06/16 01:18:07 UTC

[jira] Resolved: (HADOOP-6026) Improve the performance efficiency of task initialization at the JobTracker

     [ https://issues.apache.org/jira/browse/HADOOP-6026?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Zheng Shao resolved HADOOP-6026.
--------------------------------

    Resolution: Invalid

already fixed in 0.19.1

> Improve the performance efficiency of task initialization at the JobTracker
> ---------------------------------------------------------------------------
>
>                 Key: HADOOP-6026
>                 URL: https://issues.apache.org/jira/browse/HADOOP-6026
>             Project: Hadoop Core
>          Issue Type: Improvement
>          Components: mapred
>            Reporter: dhruba borthakur
>            Assignee: Zheng Shao
>         Attachments: HADOOP-6026.1.patch
>
>
> The JobTracker reads the splits for a job at Job Initialization time. Then, for each location in the split, it invokes DNSToSwitchMapping.resolve(). This, in turn, typically invokes an external script that resolves the hostname to a network rack location. The time spent in invoking this external script can be reduced if the hostname and their rack locations are inserted into a cache. JobTracker.resolveAndAddToTopology() can look up this cache first and avoid invoking the external "resolve" script is most cases. 

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