JobTracker lockup due to JobInProgress.initTasks taking significant time for large jobs on large clusters

• Key: HADOOP-3864
• Type: Bug
• Status: Closed
• Resolution: Fixed
• Priority: Critical
• Assignee: Arun C Murthy
• Reporter: Arun C Murthy
• Affects Version/s: 0.18.0
• Fix Version/s: 0.19.0

Description

JobInProgress.initTasks takes significant amount of time on a large cluster for large jobs (55k maps * 3 splits), during which the JobInProgress object is locked up.

Simultaneously the JobClient is calling JobTracker.getTaskCompletionEvents which locks the JobTracker & tries to lock the JobInProgress, there-by it starves all heartbeats which are trying to lock the JobTracker - resulting in a lockup.

Comments

[Arun C Murthy]

Here is the simplest patch to fix this, rather than the correct path which is to go fix the whole synchronization mess in the JobTracker (see HADOOP-869). For now, I just turn away the JobClient when the job is being initalized, thereby avoiding the problem...

-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12387251/HADOOP-3864_0_20080830.patch
against trunk revision 681243.

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

-1 tests included. The patch doesn't appear to include any new or modified tests.
Please justify why no tests are needed for this patch.

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

+1 javac. The applied patch does not increase the total number of javac compiler warnings.

+1 findbugs. The patch does not introduce any new Findbugs warnings.

+1 release audit. The applied patch does not increase the total number of release audit warnings.

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

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

Test results: http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/2991/testReport/
Findbugs warnings: http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/2991/artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html
Checkstyle results: http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/2991/artifact/trunk/build/test/checkstyle-errors.html
Console output: http://hudson.zones.apache.org/hudson/job/Hadoop-Patch/2991/console

This message is automatically generated.

[Owen O'Malley]

I just committed this. Thanks, Arun!

[Hudson]

Integrated in Hadoop-trunk #581 (See http://hudson.zones.apache.org/hudson/job/Hadoop-trunk/581/)