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https://issues.apache.org/jira/browse/YARN-4282?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Yingqi Lu updated YARN-4282:
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Attachment: flamegraph.png
> JVM reuse in Yarn
> -----------------
>
> Key: YARN-4282
> URL: https://issues.apache.org/jira/browse/YARN-4282
> Project: Hadoop YARN
> Issue Type: Improvement
> Reporter: Yingqi Lu
> Labels: performance
> Attachments: flamegraph.png
>
>
> Dear All,
> Recently, we identified an issue inside Yarn with MapReduce. There is a
> significant amount of time spent in libjvm.so and most of which is
> compilation.
> Attached is a flame graph (visual call graph) of a query running for about 8
> mins. Most of the yellow bars represent ‘libjvm.so’ functions while the java
> functions are colored in red. Data show that more than 40% of overall
> execution time is spent in compilation itself, but still a lot of code ran in
> the interpreter mode by looking inside the JVM themselves. In the ideal case,
> we want everything runs with compiled code over and over again. However in
> reality, mappers and reducers are long died before the compilation benefits
> kick in. In other word, we take the performance hit from both compilation and
> interpreter. JVM reuse feature in MapReduce 1.0 addressed this issue, but it
> was removed in Yarn. We are right now working on a bunch of JVM parameters to
> minimize the impact of the performance, but still think it would be good to
> open a discussion here to seek for more permanent solutions since it ties to
> the nature of how Yarn works.
> We are wondering if any of you have seen this issue before or if there is any
> on-going project already happening to address this?
> Data for this graph was collected across the entire system with multiple JVMs
> running. The workload we use is BigBench workload
> (https://github.com/intel-hadoop/Big-Data-Benchmark-for-Big-Bench).
> Thanks,
> Yingqi Lu
> 1. Software and workloads used in performance tests may have been optimized
> for performance only on Intel microprocessors. Performance tests, such as
> SYSmark and MobileMark, are measured using specific computer systems,
> components, software, operations and functions. Any change to any of those
> factors may cause the results to vary. You should consult other information
> and performance tests to assist you in fully evaluating your contemplated
> purchases, including the performance of that product when combined with other
> products.
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