Disabling the Just-In-Time Compiler
 Technote (troubleshooting)
 
Problem(Abstract)
Sometimes a problem in the Just-In-Time (JIT) compiler causes the IBM® WebSphere® Application Server Java™ virtual machine (JVM) to crash. If analysis of the core file (UNIX® platforms) or user.dmp file (Windows® platforms) indicates that the JIT compiler is suspect, take the following steps to disable the JIT compiler.

There will be some performance degradation when you disable the JIT compiler. The amount of performance impact you will see will be dependant on your application and your hardware. CPU utilization will increase with the JIT compiler disabled, so if your machine is already CPU bound, you will notice a more significant performance impact.
 
Resolving the problem
IMPORTANT: If you are not sure if the JIT compiler caused the crash, open a problem management record (PMR) with IBM support for analysis of the core or user.dmp.
There are different types of Java processes in releases of V5, and the JIT compiler is disabled differently for each of them. The following steps you through disabling the JIT compiler for each of the different types of Java processes:

For Application Server:
  1. In the administrative console, expand Servers, then click Application Servers.
  2. Select the Application Server.
  3. In the Additional Properties section, click Process Definition.
  4. Click Java Virtual Machine.
  5. Select the disable JIT check box.
  6. Click Apply.
  7. At the top of the administrative console, click Save to save your changes.
  8. Stop and restart the Application Server.

For Deployment Manager:
  1. In the administrative console, expand System Administration, then click DeploymentManager.
  2. In the Additional Properties section, click Process Definition.
  3. Click Java Virtual Machine.
  4. Select the disable JIT check box.
  5. Click Apply.
  6. At the top of the administrative console, click Save to save your changes.
  7. Stop and restart the Application Server.

For Node Agent:
  1. In the administrative console, expand System Administration, then click Node Agents.
  2. Select the appropriate node agent.
  3. In the Additional Properties section, click Process Definition.
  4. Click Java Virtual Machine.
  5. Select the disable JIT check box.
  6. Click Apply.
  7. At the top of the administrative console, click Save to save your changes.
  8. Stop and restart the Application Server.

For JMS Server:
  1. In the administrative console, expand servers, then click JMS Servers.
  2. Select the appropriate JMS server.
  3. In the Additional Properties section, click Process Definition.
  4. Click Java Virtual Machine.
  5. Select the disable JIT check box.
  6. Click Apply.
  7. At the top of the administrative console, click Save to save your changes.
  8. Stop and restart the Application Server.
 
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers WebSphere Application Server - Express Java development AIX, HP-UX, Linux, Solaris, Windows 5.1, 5.0
Application Servers Runtimes for Java Technology Java SDK
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Java SDK
Operating system(s): Windows
Software version: 5.1
Software edition:
Reference #: 1084185
IBM Group: Software Group
Modified date: Feb 23, 2007