Mailing-List: contact hadoop-dev-help@lucene.apache.org; run by ezmlm
Precedence: bulk
Reply-To: hadoop-dev@lucene.apache.org
Message-ID: <4817093.1197552704399.JavaMail.jira@brutus>
Date: Thu, 13 Dec 2007 05:31:44 -0800 (PST)
From: "Hadoop QA (JIRA)" <jira@apache.org>
To: hadoop-dev@lucene.apache.org
Subject: [jira] Commented: (HADOOP-2247) Mappers fail easily due to repeated
 failures
In-Reply-To: <5478354.1195680163148.JavaMail.jira@brutus>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/HADOOP-2247?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12551499 ] 

Hadoop QA commented on HADOOP-2247:
-----------------------------------

-1 overall.  Here are the results of testing the latest attachment 
http://issues.apache.org/jira/secure/attachment/12371591/HADOOP-2220.patch
against trunk revision r603824.

    @author +1.  The patch does not contain any @author tags.

    javadoc +1.  The javadoc tool did not generate any warning messages.

    javac +1.  The applied patch does not generate any new compiler warnings.

    findbugs -1.  The patch appears to introduce 1 new Findbugs warnings.

    core tests +1.  The patch passed core unit tests.

    contrib tests -1.  The patch failed contrib unit tests.

Test results: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1335/testReport/
Findbugs warnings: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1335/artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html
Checkstyle results: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1335/artifact/trunk/build/test/checkstyle-errors.html
Console output: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1335/console

This message is automatically generated.

> Mappers fail easily due to repeated failures
> --------------------------------------------
>
>                 Key: HADOOP-2247
>                 URL: https://issues.apache.org/jira/browse/HADOOP-2247
>             Project: Hadoop
>          Issue Type: Bug
>    Affects Versions: 0.15.0
>         Environment: 1400 Node hadoop cluster
>            Reporter: Srikanth Kakani
>            Assignee: Amar Kamat
>            Priority: Blocker
>             Fix For: 0.15.2
>
>         Attachments: HADOOP-2220.patch
>
>
> Related to HADOOP-2220, problem introduced in HADOOP-1158
> At this scale hardcoding the number of fetch failures to a static number: in this case 3 is never going to work. Although the jobs we are running are loading the systems 3 failures can randomly occur within the lifetime of a map. Even fetching the data can cause enough load for so many failures to occur.
> We believe that number of tasks and size of cluster should be taken into account. Based on which we believe that a ratio between total fetch attempts and total failed attempts should be taken into consideration.
> Given our experience with a task should be declared "Too many fetch failures" based on:
> failures > n /*could be 3*/ && (failures/total attempts) > k% /*could be 30-40%*/
> Basically the first factor is to give some headstart to the second factor, second factor then takes into account the cluster size and the task size.
> Additionally we could take recency into account, say failures and attempts in last one hour. We do not want to make it too small.

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