[IBM i]

Activating the heap monitor

This task describes the steps used to activate the heap monitor. Heap monitor is used with WebSphere® Application Server profiles to monitor heap size of a profile in comparison to pool size.

Before you begin

For existing WebSphere Application Server profiles, there is a script available to add the feature. See the heapMonitor script information.

About this task

You can use the heap monitor feature to monitor the Java™ Virtual Machine (JVM) heap size of a WebSphere Application Server profile in comparison to pool size. The feature is available for new WebSphere Application Server profiles or profiles that are created.

To check if a WebSphere Application Server profile has the heap monitor enabled and to activate it if necessary, perform the following steps.

Procedure

  1. Start the server for the WebSphere Application Server profile.
  2. Run the heapMonitor script with the -status flag.
    For example, for a WebSphere Application Server Version 8.5 profile named default, enter the following command in the Qshell environment:
    /QIBM/ProdData/WebSphere/AppServer/V85/ND/bin/heapMonitor -profileName default -status
    
    The output should look similar to the following:
    WASX7209I: Connected to process "server1" on node MYSERVER using SOAP connector;
     The type of process is: UnManagedProcess
     WASX7303I: The following options are passed to the scripting
      environment and are available as argument that is stored in the argv
      variable: "[status, server1]"
     HEAP0002I: The heap monitor is disabled.
     $
    
  3. To enable the heap monitor for this example, enter the following command in the Qshell environment:
    /QIBM/ProdData/WebSphere/AppServer/V85/ND/bin/heapMonitor -profileName default -enable
    The output should look similar to the following:
    WASX7209I: Connected to process "server1" on node MYSERVER using SOAP connector;
     The type of process is: UnManagedProcess
     WASX7303I: The following options are passed to the scripting environment and are
      available as argument that is stored in the argv
      variable: "[enable, server1]"  
     HEAP0005I: Enabling the heap monitor...  
     HEAP0003I: The heap monitor has been enabled. 
     $
    
  4. Stop and start the server.

Results

The following message typically appears in the Display Message command (DSPMSG QSYSOPR):
HEAP MONITOR STARTED FOR 012500/QEJBSVR/SERVER1 IN SUBSYSTEM qwas85 IN POOL
  *BASE POOL ID=2 POOLSIZE(B)=1687994368 RESERVED(B)=778240 HEAP
  TOTAL(B)=202276864 FREE(B)=67037600 USEDHEAP=135239264
  OS400.GC.HEAP.SIZE.MAX(KB)  =240000000
The heap monitor is activated.