JVM Monitoring

This section describes the types, names, and meanings of JVM metrics collected by APM.

**Table 1** Collection parameters for JVM monitoring
Parameter	Data Type	Application Type	Default	Supported Start Agent Version	Supported End Agent Version	Description
Trace Stack Collection Threshold	integer	JAVA	0	2.0.4	-	Stacks will be automatically printed when the request latency exceeds the threshold.

**Table 2** JVM monitoring metrics
Category	Metric	Name	Description	Unit	Data Type	Default Aggregation Mode
Class loading (classLoading: JVM class loading statistics)	loadedClassCount	Loaded Classes	Number of loaded classes	-	INT	SUM
	totalLoadedClassCount	Total Loaded Classes	Total number of loaded classes	-	INT	SUM
	unloadedClassCount	Unloaded Classes	Number of unloaded classes	-	INT	SUM
Compilation (compile: JVM class compilation time statistics)	compilationTime	Compilation Time	Compilation time in a collection period	ms	INT	SUM
	totalCompilationTime	Total Compilation Time	Total compilation time	ms	INT	SUM
CPU (CPU: CPU usage statistics of JVM processes)	cpuRatio	CPU Usage	CPU usage of the Java process	%	DOUBLE	AVG
	cpuRatioMax	Max. CPU Usage	Maximum CPU usage of the Java process	%	DOUBLE	MAX
	cpuTimeInterval	CPU Time	CPU time of the Java process in the collection interval	ns	INT	SUM
	processorCount	Processors	Number of processors	-	INT	SUM
	systemTimeInterval	Collection Interval	Collection interval	ns	INT	SUM
	totalCpuTime	Total CPU Time	Total CPU time	ns	INT	SUM
Memory (memory: JVM memory statistics)	directMemoryUsage	Direct Memory	Used direct memory	M	INT	AVG
	directMemoryCapacity	Direct Memory Capacity	Total direct memory capacity	M	INT	AVG
	heapMemoryUsage	Heap Memory	Used heap memory	M	INT	AVG
	nonHeapMemoryUsage	Non-Heap Memory	Used non-heap memory	M	INT	AVG
	objectPendingFinalizationCount	Objects Being Recycled	Number of objects that are being recycled at the time of collection	-	INT	SUM
Memory pool (memoryPool: statistics collected by JVM memory pool)	committed	Available Memory	Available memory	Byte	INT	SUM
	init	Initialized Memory	Initialized memory	Byte	INT	SUM
	max	Max. Memory	Maximum memory	Byte	INT	SUM
	name	Memory Pool Name	Memory pool name	-	ENUM	LAST
	used	Used Memory	Used memory	Byte	INT	SUM
Thread (thread: JVM thread statistics)	currentThreadCpuTime	Thread CPU Time	CPU time of the current thread	-	INT	SUM
	currentThreadUserTime	Thread User Time	User time of the current thread	-	INT	SUM
	daemonThreadCount	Daemon Threads	Number of daemon threads	-	INT	SUM
	deadlockedThreadsCount	Deadlock Threads	Number of deadlock threads	-	INT	SUM
	monitorDeadlockedThreads	Current Deadlock Threads	ID list of current deadlock threads	-	INT	SUM
	peakThreadCount	Max. Threads Executed	Maximum number of threads executed	-	INT	SUM
	threadCount	Current Threads	Number of current threads	-	INT	SUM
	totalStartedThreadCount	Total Threads	Total number of threads that are started since the Java process is started	-	INT	SUM
	newThreadCount	Initial Threads	Number of threads in the initial state	-	INT	SUM
	runnableThreadCount	Running Threads	Number of running threads	-	INT	SUM
	blockedThreadCount	Blocked Threads	Number of blocked threads	-	INT	SUM
	waitingThreadCount	Pending Threads	Number of pending threads	-	INT	SUM
	timedWaitingThreadCount	Timed-out Threads	Number of threads that timed out	-	INT	SUM
	terminatedThreadCount	Terminated Threads	Number of terminated threads	-	INT	SUM