[
https://issues.apache.org/jira/browse/MAPREDUCE-2932?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13098576#comment-13098576
]
Harsh J commented on MAPREDUCE-2932:
------------------------------------
I s'pose NodeManagerMetrics is the newer equivalent of the older, pluggable
instrumentation of TT. Since NodeManagerMetrics is not an interface, and nor
does the framework allow things to just be plugged in (to merely override the
metrics class) for this, I do not think this problem exists MR2 (0.23/trunk).
> Missing instrumentation plugin class shouldn't crash the TT startup per design
> ------------------------------------------------------------------------------
>
> Key: MAPREDUCE-2932
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-2932
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Components: tasktracker
> Affects Versions: 0.20.2
> Reporter: Harsh J
> Assignee: Harsh J
> Priority: Trivial
> Attachments: 0.20-MAPREDUCE-2932.r1.diff
>
>
> Per the implementation of the TaskTracker instrumentation plugin
> implementation (from 2008), a ClassNotFoundException during loading up of an
> configured TaskTracker instrumentation class shouldn't have hampered TT start
> up at all.
> But, there is one class-fetching call outside try/catch, which makes TT fall
> down with a RuntimeException if there's a class not found. Would be good to
> include this line into the try/catch itself.
> Strace would appear as:
> {code}
> 2011-08-25 11:45:38,470 ERROR org.apache.hadoop.mapred.TaskTracker: Can not
> start task tracker because java.lang.RuntimeException:
> java.lang.RuntimeException: java.lang.ClassNotFoundException:
> org.apache.hadoop.mapred.CustomInstPlugin
> at org.apache.hadoop.conf.Configuration.getClass(Configuration.java)
> at
> org.apache.hadoop.mapred.TaskTracker.getInstrumentationClass(TaskTracker.java)
>
> at org.apache.hadoop.mapred.TaskTracker.initialize(TaskTracker.java)
> {code}
--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira
