[
https://issues.apache.org/jira/browse/MAPREDUCE-2637?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13064081#comment-13064081
]
Harsh J commented on MAPREDUCE-2637:
------------------------------------
Arun - Yep, I know about that option. I had tried this out (the ports, as a
hack) once earlier, and the interactive debug option looks like a more
lucrative one to me, however difficult to achieve on a distributed system
(perhaps it makes no sense at all today, when you factor in mrunit/etc. tools
which are available now.)
I believe my trials also had me include jmx ports this way, and that was really
beneficial (although crazy), to see stats update live via a remotely attached
visualvm :)
> Providing options to debug the mapreduce user code (Mapper, Reducer,
> Combiner, Sort implementations)
> ----------------------------------------------------------------------------------------------------
>
> Key: MAPREDUCE-2637
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-2637
> Project: Hadoop Map/Reduce
> Issue Type: Improvement
> Components: tasktracker
> Reporter: Devaraj K
> Assignee: Devaraj K
>
> Presently Hadoop provides "mapred.child.java.opts" configuration which can be
> used to set JVM options for Child JVM running Map or Reduce Task.
> If we need to remote debug the Child JVM, we can add remote debugging options
> to this configuration value.
> But this will work only for single Child JVM. Other children will fail as the
> remote debugging port is already used.
> We cannot specify the remote debugging port dynamically.
> As a result, it's not possible to remote debug multiple Child JVMs.
> As a solution to this problem, we can provide a configuration to debug Task
> JVMs in this scenario.
--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira
