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Posted to mapreduce-dev@hadoop.apache.org by Jeffrey Naisbitt <jn...@yahoo-inc.com> on 2011/05/23 17:57:46 UTC

Review Request: MAPREDUCE-2489 Jobsplits with random hostnames can make the queue unusable

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https://reviews.apache.org/r/776/
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Review request for hadoop-mapreduce.


Summary
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We saw an issue where a custom InputSplit was returning invalid hostnames (non-repeating) for the splits that were then causing the JobTracker to attempt to excessively resolve host names. This caused a major slowdown for the JobTracker. We should prevent invalid InputSplit hostnames from affecting everyone else.

I propose we implement some verification for the hostnames to try to ensure that we only do DNS lookups on valid hostnames (and fail otherwise). We could also fail the job after a certain number of failures in the resolve.

NOTE: This requires the changes in HADOOP-7314


This addresses bug MAPREDUCE-2489.
    https://issues.apache.org/jira/browse/MAPREDUCE-2489


Diffs
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  trunk/ivy.xml 1125074 
  trunk/ivy/libraries.properties 1125074 
  trunk/src/contrib/mumak/src/java/org/apache/hadoop/mapred/SimulatorJobTracker.java 1125074 
  trunk/src/java/org/apache/hadoop/mapred/JobInProgress.java 1125074 
  trunk/src/java/org/apache/hadoop/mapred/JobTracker.java 1125074 

Diff: https://reviews.apache.org/r/776/diff


Testing
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Thanks,

Jeffrey