Java virtual machine counters

You can use the Java virtual machine (JVM) counters that the Performance Monitoring Infrastructure (PMI) and Tivoli Performance Viewer (TPV) collect to monitor JVM performance.

Except for the counters that are used for total, used, and free heap size, you can find the counters by using the Java virtual machine Profiler Interface (JVMPI). To use JVMPI, you must turn on the monitoring by setting the -XrunpmiJvmpiProfiler command line. See Enabling the Java virtual machine profiler data for more information.

Counter definitions

Name Key Description Granularity Type Level Overhead ID
FreeMemory jvmRuntimeModule.freeMemory The free memory in the JVM run time Per Java Virtual Machine (JVM) CountStatistic Extended Low 2
UsedMemory jvmRuntimeModule.usedMemory The used memory in the JVM run time Per JVM CountStatistic Basic Low 3
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
UpTime jvmRuntimeModule.upTime The amount of time that the JVM is running Per JVM CountStatistic Basic Low 4
GCCount jvmRuntimeModule.numGcCalls The number of garbage collection calls. This counter is not available unless the -XrunpmiJvmpiProfiler option is set when starting the JVM. Per JVM CountStatistic All Max 11
GCIntervalTime jvmRuntimeModule.avgTimeBetweenGcCalls The average garbage collection value in seconds between two garbage collections. This counter is not available unless the -XrunpmiJvmpiProfiler option is set when starting the JVM. Per JVM TimeStatistic All Max 12
GCTime jvmRuntimeModule.avgGcDuration The average duration of a garbage collection. This counter is not available unless the -XrunpmiJvmpiProfiler option is set when starting the JVM. 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 -XrunpmiJvmpiProfiler option is set when starting the JVM. 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 -XrunpmiJvmpiProfiler option is set when starting the JVM. Per JVM TimeStatistic All Max 20
ObjectAllocateCount jvmRuntimeModule.numObjectsAllocated 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 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 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
ThreadStartedCount jvmRuntimeModule.numThreadsStarted The number of threads started. This counter is not available unless the -XrunpmiJvmpiProfiler option is set when starting the JVM. Per JVM CountStatistic All Max 17
ThreadEndedCount jvmRuntimeModule.numThreadsDead The number of failed threads. This counter is not available unless the -XrunpmiJvmpiProfiler option is set when starting the JVM. Per JVM CountStatistic All Max 18



Related tasks
Enabling the Java virtual machine profiler data
Related reference
PMI data organization
Reference topic    

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