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Posted to common-dev@hadoop.apache.org by Shrinivas Joshi <js...@gmail.com> on 2010/06/17 00:53:06 UTC

JIT debug symbols and OProfile under Hadoop

Hello,



I am trying to get profiles for a workload running on top of Hadoop 0.20.2
framework. The workload jars and Hadoop jars have been compiled with debug
symbols enabled. I could see local variable tables and line number tables in
the jar class files using javap. I am passing the right value for *agentpath
* flag pointing to oprofile JVMTI agent and I am also seeing it passed
correctly to map and reduce JVMs from *ps *output. This is done through
conf/mapred-site.xml properties. However, in the profiles I am unable to see
meaningful samples for JITed code; everything is getting attributed to anon
samples.



Profiling a test app works just fine with the same JVM that is being used by
Hadoop. I can see the right debug symbols being attributed in the resulting
profiling. In fact, I even tried profiling a JVM process that was spawned
using *ProcessBuilder* API, the way Hadoop spawns its map and reduce JVMs,
that seem to work fine too.



Does anybody have any pointers as to what I might be missing here? Has
anybody successfully collected profiles showing JIT debug symbols for any
Hadoop workload? I am using OProfile 0.9.6.



Thanks,

-Shrinivas