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https://issues.apache.org/jira/browse/HADOOP-3994?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12624507#action_12624507
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Jason commented on HADOOP-3994:
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The window's jvm equivalent is java.lang.ProcessImpl.java and has the process
handle in the private long variable handle.
I suspect having an equivalent for this would be straight forward but I don't
currently develop under windows so I didn't try to implement an equivalent.
The code uses reflection right now to get at the private variables - definitly
fragile. I tried very hard to ensure that there would be no crashes if the
something was not as expected.
> There is little information provided when the TaskTracker kills a Task that
> has not reported within the timeout (600 sec) interval - this patch provides
> a stack trace of the task
> -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: HADOOP-3994
> URL: https://issues.apache.org/jira/browse/HADOOP-3994
> Project: Hadoop Core
> Issue Type: New Feature
> Components: mapred
> Affects Versions: 0.16.0
> Reporter: Jason
> Priority: Minor
> Attachments: 0.16_patch
>
>
> When we have a task that is killed for not reporting, sometimes there is an
> obvious programming error, and sometimes the reason the job didn't report is
> unclear.
> This patch will cause the TaskTracker to try to generate a stack trace of the
> offending task before the task is killed.
> Given how opaque process control is in java, a program is run to generate the
> stack trace, using the PID extracted from the undocumented UNIXProcess class
> The attached patch is against 0.16.0, as that is the release we use.
> This will only work on Unix machines -- or JVM's what use the
> java.lang.UNIXProcess implementation for the java Process object.
> The script that generates the stack trace is very linux specific.
> The code changes will run on jvm's where the UNIXProcess class is not
> available, without failure, but no stack trace will be generated.
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