Re: oprofile on mapreduce tasks (java)

Thank you guys for useful comments. I just fixed the issue.
Indeed, each child task has its own JVM and I need to pass -agentlib when
they are spawned.
This can be done by adding the following in mapred-site.xml in hadoop.
(The configuration is only effective for the child JVMs spawned by
TaskTracker.)
<property>


    <name>mapred.child.java.opts</name>


    <value>-agentlib:jvmti_oprofile</value>


</property>

Thanks again for the helps.

Tommy



On Fri, Aug 15, 2014 at 8:55 AM, Maynard Johnson <[email protected]>
wrote:

> On 08/14/2014 06:09 PM, Tommy wrote:
> > Hi,
> >
> > I am trying to profile mapreduce task using operf.
> > I have some troubles with getting correct symbols of java threads.
> >
> > What I did was to operf the tasktracker which spawns map and reduce
> tasks (threads).
> > I did like the following to start the tasktracker.
> > *operf /usr/lib/jvm/java-oracle/bin/java -agentlib:jvmti_oprofile ......*
> >
> > However, only the tasktracker thread gets the correct symbols for all
> addresses. I found that only one ".jo" file is created for the tasktracker,
> not the child threads that inherit the tasktracker, such as map and reduce
> tasks. All the child threads get "anon".
> It sounds like some additional JVMs are being spawned . . . so you need to
> be sure to pass the -agentlib on those invocations. And how that can be
> done is not something we can help with.  It requires knowledge of the
> application structure.
>
> -Maynard
> >
> > Please help me to resolve the issue.
> > Thank you very much.
> >
> > Tommy
> >
> >
> >
> ------------------------------------------------------------------------------
> >
> >
> >
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> >
>
>

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