Resource statistics data: Java Virtual Machine (JVM)

Learn about the data that is returned for the JVM resource type when you activate resource statistics collection.

You can view these statistics in the web user interface, or you can write a program that subscribes to a publication (single XML message) that returns this data. For an example of the publication message, see Example XML output.

Each integration server starts its own Java™ Virtual Machine (JVM), which provides support for all Java activities in that integration server. Some Java activity is present in the integration server even if you have not yet deployed or started message flows in that group. Use these resource statistics to review how much memory is in use by the JVM, and how often garbage collection might be occurring in the integration server.

Statistics are collected for the following JVM resources:
  • Heap memory
  • Non-heap memory
  • Garbage collection

A summary is also provided, which adds the values in the three groups.

The special value -1 is returned for measurements that are undefined or are not set.

The following table describes the measurements that are returned for each of the listed resources. The garbage collection measurements are cumulative, and continue to increase until you stop statistics collection.
Measurements Resource Description
InitialMemoryInMB
  • Heap memory
  • Non-heap memory
 The initial amount of memory that the JVM requests from the operating system for memory management during startup. Its value might be undefined.
UsedMemoryinMB
  • Heap memory
  • Non-heap memory
 The amount of memory that is currently in use.
CommittedMemoryInMB
  • Heap memory
  • Non-heap memory
 The amount of memory that is allocated to the JVM by the operating system.
MaxMemoryInMB
  • Heap memory
  • Non-heap memory
 The maximum amount of memory that can be used for memory management. Its value might be undefined.
CumulativeGCTimeInSeconds Garbage collection The accumulated garbage collection elapsed time in seconds for this instance of the JVM. Its value might be undefined.
CumulativeNumberOfGCCollections Garbage collection The total number of garbage collections that have occurred for this instance of the JVM. Its value might be undefined.