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From "Ravi Gummadi (JIRA)" <j...@apache.org>
Subject [jira] Updated: (HADOOP-2774) Add counters to show number of key/values that have been sorted and merged in the maps and reduces
Date Fri, 14 Nov 2008 09:26:44 GMT

     [ https://issues.apache.org/jira/browse/HADOOP-2774?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Ravi Gummadi updated HADOOP-2774:
---------------------------------

    Attachment: HADOOP-2774.patch

New patch attached here.
As Sharad pointed out, since most of the writes to disk happen through IFile.Writer.append(),
this new code maintains a count of records written.
I verified the spilled records count with wordcount example and test inputs with different
values of io.sort.mb, io.sort.factor and different number of maps & reduces.

Please do the review of code changes.

> Add counters to show number of key/values that have been sorted and merged in the maps
and reduces
> --------------------------------------------------------------------------------------------------
>
>                 Key: HADOOP-2774
>                 URL: https://issues.apache.org/jira/browse/HADOOP-2774
>             Project: Hadoop Core
>          Issue Type: Bug
>            Reporter: Owen O'Malley
>            Assignee: Ravi Gummadi
>             Fix For: 0.20.0
>
>         Attachments: HADOOP-2774.patch, HADOOP-2774.patch
>
>
> For each *pass* of the sort and merge, I would like a count of the number of records.
So for example, if the map output 100 records and they were sorted once, the counter would
be 100. If it spilled twice and was merged together, it would be 200. Clearly in a multi-level
merge, it may not be a multiple of the number of map output records. This would let the users
easily see if they have values like io.sort.mb or io.sort.factor set too low.

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