Thanks Rohini. Yeah I was able to get Xprof runs successfully in the past.
Was hoping to get something a bit more detailed. Unsure as to why my hprof
attempts in Tez take forever whereas the job in Hadoop seems to proceed
(albeit slowly).

On Wed, Jan 18, 2017 at 4:18 PM, Rohini Palaniswamy <[email protected]
> wrote:

> Try
>
> tez.task.launch.cmd-opts = '-Xprof ...rest of your java opts....'
> -agentlib:hprof=cpu=samples,heap=sites,force=n,thread=y,verbose=n,file=%s
> is very costly and time consuming. -Xprof is very lightweight. http://
> stackoverflow.com/questions/32083547/explanation-of-java-
> xprof-output/32087981#32087981 has information on interpreting the
> results.
>
> On Wed, Jan 18, 2017 at 4:09 PM, Piyush Narang <[email protected]>
> wrote:
>
>> hi folks,
>>
>> I had a couple of Cascading3 on Tez jobs that seemed to be running slower
>> on Tez as compared to Hadoop. Wanted to try and get some hprof profiles to
>> see what the jobs are spending time on, so thought I'd try and get a hprof
>> profile. I tried running the job with:
>>
>> -Dmapreduce.task.profile=true \
>>
>> -Dtez.task.launch.cluster-default.cmd-opts="-XX:+UseSerialGC
>> -Djava.net.preferIPv4Stack=true -XX:ReservedCodeCacheSize=128M
>> -XX:MaxMetaspaceSize=256M -XX:CompressedClassSpaceSize=256M
>> -XX:CICompilerCount=2 -XX:HeapDumpPath=<LOG_DIR>/heapdump-@[email protected]
>> -XX:ErrorFile=<LOG_DIR>/hs_err_pid-@[email protected]
>> -agentlib:hprof=cpu=samples,heap=sites,force=n,thread=y,verb
>> ose=n,file=<LOG_DIR>/profile-@[email protected]"
>> Now when I kick off the Tez job, it seems to spend very long (upwards of
>> an hour) stuck at 0%. The tasks don't seem to proceed beyond this:
>>
>> 2017-01-18 23:53:26,261 [INFO] [TezChild] |tez.FlowProcessor|: flow node id: 
>> E08C07BFB10141D8B6D7211E5AF172E4, all 1 inputs ready in: 00:00:00.002
>>
>>
>> Tried capturing some jstacks and the top of the stack seems to hold some 
>> hprof
>>
>> related frames.
>>
>>
>> Has anyone been able to profile their Tez jobs with hprof? Are there any 
>> other
>>
>> settings I'm missing?
>>
>>
>> Same set of options(replace tez.task.launch.cluster-default.cmd-opts with 
>> mapreduce.task.profile.params) seem to work fine in case of Hadoop. I end up 
>> getting the
>>
>> hprof profiles there.
>>
>>
>> Thanks,
>>
>> --
>> - Piyush
>>
>
>


-- 
- Piyush

Reply via email to