WAS v8.5 > Reference > Administrator best practices

Java virtual machine counters

We can use the JVM counters the Performance Monitoring Infrastructure (PMI) and Tivoli Performance Viewer (TPV) collect to monitor JVM performance.

The total, used, and free heap size counters are available without any additional configuration settings. The remaining counters are available only when a Java virtual machine profiler is enabled.

Counter definitions

Counter definitions. The following table describes JVM counters.

Name	Key	Description	Granularity	Type	Level	Overhead	ID
FreeMemory	jvmRuntimeModule.freeMemory	The free memory in the JVM run time	Per JVM	CountStatistic	Extended	Low	2
HeapSize	jvmRuntimeModule.totalMemory	The total memory in the JVM run time	Per JVM	BoundedRangeStatistic. The upperBound and lowerBound are not implemented for the Total memory counter.	Basic	High	1
ProcessCpuUsage	jvmRuntimeModule.cpuUsage	The CPU Usage (in percent) of the Java virtual machine.	Per JVM	CountStatistic	Basic	Low	5
UpTime	jvmRuntimeModule.upTime	The amount of time the JVM is running	Per JVM	CountStatistic	Basic	Low	4
UsedMemory	jvmRuntimeModule.usedMemory	The used memory in the JVM run time	Per JVM	CountStatistic	Basic	Low	3
GCcount	jvmRuntimeModule.numGcCalls	The number of garbage page calls. This counter is not available unless the JVM profiler is enabled.	Per JVM	CountStatistic	All	Max	11
GCIntervalTime	jvmRuntimeModule.avgTimeBetweenGcCalls	The average garbage page value in milliseconds between two garbage collections. This counter is not available unless the JVM profiler is enabled.	Per JVM	TimeStatistic	All	Max	12
GCTime	jvmRuntimeModule.avgGcDuration	The average time duration in milliseconds of a garbage page. This counter is not available unless the JVM profiler is enabled.	Per JVM	TimeStatistic	All	Max	13
WaitsForLockCount	jvmRuntimeModule.numWaitsForLock	The number of times that a thread waits for a lock. This counter is not available unless the JVM profiler is enabled.	Per JVM	CountStatistic	All	Max	19
WaitForLockTime	jvmRuntimeModule.avgTimeWaitForLock	The average time that a thread waits for a lock. This counter is not available unless the JVM profiler is enabled.	Per JVM	TimeStatistic	All	Max	20
ThreadStartedCount	jvmRuntimeModule.numThreadsStarted	The number of threads started. This counter is not available unless the JVM profiler is enabled.	Per JVM	CountStatistic	All	Max	17
ThreadEndedCount	jvmRuntimeModule.numThreadsDead	The number of failed threads. This counter is not available unless the JVM profiler is enabled.	Per JVM	CountStatistic	All	Max	18
ObjectAllocateCount	jvmRuntimeModule.numObjectsAllocated Deprecated feature: This counter only applies to Versions 4.0 - 6.0.x. It was deprecated in v6.1.	The number of objects that are allocated in the heap. This counter is not available unless the -XrunpmiJvmpiProfiler option is set when starting the JVM.	Per JVM	CountStatistic	All	Max	14
ObjectMovedCount	jvmRuntimeModule.numObjectsMoved Deprecated feature: This counter only applies to Versions 4.0 - 6.0.x. It was deprecated in v6.1.	The number of objects in the heap. This counter is not available unless the -XrunpmiJvmpiProfiler option is set when starting the JVM.	Per JVM	CountStatistic	All	Max	16
ObjectFreedCount	jvmRuntimeModule.numObjectsFreed Deprecated feature: This counter only applies to Versions 4.0 - 6.0.x. It was deprecated in v6.1.	The number of objects freed in the heap. This counter is not available unless the -XrunpmiJvmpiProfiler option is set when starting the JVM.	Per JVM	CountStatistic	All	Max	15

The statistics that are gathered through the JVM Tool Interface (JVMTI) are different for the JVM provided by IBM than the statistics that are gathered are for the Sun HotSpot-based JVM, including Sun HotSpot JVM on Solaris and the JVM provided by Hewlett-Packard for HP-UX. gotcha

Related

Enable the Java virtual machine profiler data

Reference:

PMI data organization

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