MustGather: Out of Memory errors on AIX, Linux, or Windows
 Technote (troubleshooting)
 
Problem(Abstract)
Collecting data for Out of Memory errors with IBM® WebSphere® Application Server. Gathering this information before calling IBM Support will help familiarize you with the troubleshooting process and save you time.
 
Cause
An Out of Memory error is generally indicated when a java.lang.OutofMemoryError exception is thrown. Two conditions can cause a java.lang.OutOfMemoryError exception to occur:
  1. The Java™ Virtual Machine (JVM) might run out of contiguous Java heap space to allocate a Java object.

  2. The JVM might not be able to allocate native memory.
 
Resolving the problem
If you have already contacted support, please continue through this document as requested by your support representative. Otherwise, refer to MustGather: Read first for all WebSphere Application Server products.

Out of Memory specific MustGather information
  1. Enable verbosegc. For more details, see Enabling verbosegc in WebSphere Application Server.

  2. Stop the WebSphere Application Server.

  3. Clear all Application Server log files.

  4. Restart the Application Server.

  5. Recreate the Out of Memory condition, or wait for the condition to reoccur.

  6. When the problem has occurred, examine the verbosegc output:
    • If the verbosegc output contains the token "action=6" (1.4.2), shows "Processing OutOfMemory" messages, or shows that javacores and heapdumps were generated, the issue is likely with the HEAP. Skip to Step 8.

    • If the verbosegc output shows malloc errors, the heap is not fully expanded, or the SystemOut.log shows threading related OutOfMemory error messages, the issue is likely with the NATIVE MEMORY. Continue to Step 7.

  7. NATIVE MEMORY ONLY: For native memory problems, a system core file will be required and ideally some OS specific logging. Follow the links below for steps on processing the core file and submitting it to IBM. If possible, perform the following actions based on your operating system. If the process previously crashed with no system core please set this up for any future errors while debugging.
  8. Collect the following:
    • All files located in the following directory:
      • For WebSphere Application Server V6.0 and 6.1:
        • AIX or Linux:

          profile_root/logs/server_name

        • Windows:

          profile_root\logs\server_name  

      • For WebSphere Application Server V5.0 and 5.1:
        • AIX or Linux:

          install_root/logs/server_name

        • Windows:

          install_root\logs\server_name

    • Collect all heapdump*.* files, javacore*.* files, and server.xml for the affected server. Please provide each heapdump in a separate jar or zip file.


  9. Follow the instructions for Submitting data to IBM Support to send in the preceding diagnostic information.

For a listing of all technotes, downloads, and educational materials specific to Out of Memory errors, search the WebSphere Application Server support site.
 
Related information
Submitting information to IBM support
Steps to get support
MustGather: Readme first
Solaris Memory Issues - Heap
Solaris Memory Issues - Native
HP-UX Memory Exceptions
 
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers WebSphere Application Server - Express Hangs/performance degradation AIX, Linux, Windows 6.1, 6.0, 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 > Out of Memory
Operating system(s): Windows
Software version: 6.1
Software edition:
Reference #: 1138587
IBM Group: Software Group
Modified date: Jul 22, 2008