JVM_INFO view

The JVM_INFO view returns information about active Java Virtual Machine (JVM) jobs. The information is a subset of what can be found interactively using the Work with JVM Jobs (WRKJVMJOB) command.

The following table describes the columns in the view. The schema is QSYS2.

Table 1. JVM_INFO view
Column Name System Column Name Data Type Description
JOB_NAME JOB_NAME VARCHAR(28) The qualified job name for the active JVM.
PROCESS_ID PROCESS_ID INTEGER The process identifier used by the kernel to uniquely identify the process.
START_TIME START_TIME TIMESTAMP The current time when the JVM was started.
INITIAL_THREAD_TASKCOUNT INITTHDNUM BIGINT The number of threads initiated for this JVM when the JVM was started.
JAVA_THREAD_COUNT JAVATHDNUM BIGINT The current number of java threads within the JVM job.
TOTAL_GC_TIME ACCUMTIME BIGINT Total time spent performing garbage collection tasks in milliseconds.
GC_CYCLE_NUMBER GC_CYCLE INTEGER The current or last garbage collection cycle performed.
GC_POLICY_NAME GCPOLICY VARGRAPHIC(16)
CCSID 1200
The name of the garbage collection policy in use.
JAVA_HOME JAVA_HOME VARGRAPHIC(1024)
CCSID 1200
The java.home environment variable value in effect for this JVM.

This value indicates the JDK that is used when running a Java application. The location of the Java tools and utilities is in one of two directories, either <JAVA_HOME>/jre/bin or <JAVA_HOME>/bin, where <JAVA_HOME> is the value of the JAVA_HOME environment variable. For example, if JAVA_HOME is set to /QOpenSys/QIBM/ProdData/JavaVM/jdk60/32bit, indicating that IBM Technology for Java 6 32-bit is to be used, then the Java tools and utilities directories would be:

/QOpenSys/QIBM/ProdData/JavaVM/jdk60/32bit/bin  
/QOpenSys/QIBM/ProdData/JavaVM/jdk60/32bit/jre/bin
USER_DIRECTORY USER_DIR VARGRAPHIC(1024)
CCSID 1200
The user working directory for the JVM.

This also indicates the location where diagnostic detail will be dumped for the JVM.

NUM_CURRENT_PROPERTIES NUMPROP INTEGER Total number of Java system properties currently present.
INITIAL_HEAP_SIZE INTHEAP BIGINT The initial heap size available to the JVM code, in kilobytes.
CURRENT_HEAP_SIZE CURHEAP BIGINT The amount of memory, in kilobytes, currently allocated for heap space.
IN_USE_HEAP_SIZE INUSEHEAP BIGINT The amount of memory, in kilobytes, currently in use by the heap.
MAX_HEAP_SIZE MAXHEAP BIGINT The maximum heap size available to the JVM code, in kilobytes.
MALLOC_MEMORY_SIZE MALLOCSIZE BIGINT The amount of memory, in kilobytes, that has been allocated with malloc().
INTERNAL_MEMORY_SIZE INTMEM BIGINT The amount of memory, in kilobytes, that the JVM is using for internal operations.
JIT_MEMORY_SIZE JITSIZE BIGINT The size of the memory space, in kilobytes, that is used by the JIT (Just in Time) compiler.
SHARED_CLASS_SIZE SHAREDSIZE BIGINT The amount of memory, in kilobytes, that the JVM is using for shared classes.
BIT_MODE BIT_MODE INTEGER The Java version of this job.
32
32 bit Java job
64
64 bit Java job

Example

Examine the active JVM jobs, ordered by top heap space consumption.

 SELECT * FROM QSYS2.JVM_INFO
    ORDER BY CURRENT_HEAP_SIZE DESC