JVM_INFO table function
The JVM_INFO table function returns information about active Java™ Virtual Machine (JVM) jobs. A default wait time can be set for a JVM response.
The information returned is similar to the detail available through the Work with JVM Jobs (WRKJVMJOB) CL command.
Authorization: The caller must have *JOBCTL special authority to see values for columns other than the job name columns and PROCESS_ID.
- wait-time
- An integer value that provides the amount of time to wait, in seconds, for a JVM to return information. Valid values are 1 to 120.
The result of the function is a table containing rows with the format shown in the following table. All the columns are nullable.
| Column Name | Data Type | Description |
|---|---|---|
| JOB_NAME | VARCHAR(28) | The qualified job name for the active JVM. |
JOB_NAME_SHORT |
VARCHAR(10) |
The name of the job for the active JVM. |
| JOB_USER |
VARCHAR(10) |
The user profile that started the job for the active JVM. |
| JOB_NUMBER |
VARCHAR(6) |
The job number of the job for the active JVM. |
| PROCESS_ID | INTEGER | The process identifier used by the kernel to uniquely identify the process. |
| START_TIME | TIMESTAMP | The current time when the JVM was started. |
| INITIAL_THREAD_TASKCOUNT | BIGINT | The taskcount or TDE number of the JVM's initial thread. The taskcount or TDE number is a unique identifier assigned to each job, thread, and task running in the system. |
| JAVA_THREAD_COUNT | BIGINT | The current number of java threads within the JVM job. |
| TOTAL_GC_TIME | BIGINT | Total time spent performing garbage collection tasks in milliseconds. |
| GC_CYCLE_NUMBER | INTEGER | The current or last garbage collection cycle performed. |
| GC_POLICY_NAME | VARGRAPHIC(16) CCSID 1200
|
The name of the garbage collection policy in use. |
| 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 | 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 | INTEGER | Total number of Java system properties currently present. |
| INITIAL_HEAP_SIZE | BIGINT | The initial heap size available to the JVM code, in kilobytes. |
| CURRENT_HEAP_SIZE | BIGINT | The amount of memory, in kilobytes, currently allocated for heap space. |
| IN_USE_HEAP_SIZE | BIGINT | The amount of memory, in kilobytes, currently in use by the heap. |
| MAX_HEAP_SIZE | BIGINT | The maximum heap size available to the JVM code, in kilobytes. |
| MALLOC_MEMORY_SIZE | BIGINT | The amount of memory, in kilobytes, that has been allocated with malloc(). |
| INTERNAL_MEMORY_SIZE | BIGINT | The amount of memory, in kilobytes, that the JVM is using for internal operations. |
| JIT_MEMORY_SIZE | BIGINT | The size of the memory space, in kilobytes, that is used by the JIT (Just in Time) compiler. |
| SHARED_CLASS_SIZE | BIGINT | The amount of memory, in kilobytes, that the JVM is using for shared classes. |
| BIT_MODE | INTEGER | The Java version of this
job.
|
Example
- Show information for all JVMs on the system. Do not wait longer than 10 seconds for the results
of any individual JVM to be returned.
SELECT * FROM TABLE(QSYS2.JVM_INFO(WAIT_TIME => 10));