tree 5a5007957f5926476d84db9abc4b91e08e5ffbc5
parent dcdbaf12224e7029dde3110d56edea022dd3a2a0
author Sahil Takiar <takiar.sahil@gmail.com> 1599173443 -0700
committer Sahil Takiar <stakiar@cloudera.com> 1600818357 +0000

IMPALA-9046: Profile counter that indicates if a JVM pause occurred

Adds a new section to the host profiles that includes JVM GC related
metrics. These metrics are taken from JMX and the JvmPauseMonitor.

The host profiles will now include a section like below:

        JVM:
           - GcCount: 19
           - GcNumInfoThresholdExceeded: 0
           - GcNumWarnThresholdExceeded: 0
           - GcTimeMillis: 17s476ms
           - GcTotalExtraSleepTimeMillis: 380

GcNumInfoThresholdExceeded, GcNumWarnThresholdExceeded, and
GcTotalExtraSleepTimeMillis are all taken from JvmPauseMonitor.
GcCount and GcTimeMillis are taken from JMX (specifically,
GarbageCollectorMXBean).

The counters themselves are derived from the impalad host-level metrics.

Changed the 'lock_' in JvmMetricCache (in memory-metrics.h) from a mutex
to a shared_mutex. Most accessors of the JvmMetricCache member variables
are read-only. A write only occurs lazily at most every second. This
should help reduce lock contention on JvmMetricCache now that all
queries will start accessing info stored by the JvmMetricCache.

Testing:
* Ran core tests
* Added a test that runs Java UDF, which triggers JVM GC

Change-Id: Idbaae2f9142b8be94532a0a147668a3d96091b0b
Reviewed-on: http://gerrit.cloudera.org:8080/16414
Reviewed-by: Tim Armstrong <tarmstrong@cloudera.com>
Reviewed-by: Sahil Takiar <stakiar@cloudera.com>
Tested-by: Sahil Takiar <stakiar@cloudera.com>