MustGather: Out of Memory errors on Windows, Part 2b - Heap Leak
 Technote (troubleshooting)
 
Problem(Abstract)
MustGather for troubleshooting WebSphere® Application Server java.lang.OutOfMemoryError errors on the Windows® platform when you suspect a memory leak in the Java™ heap. Base this action on your analysis of the documentation collected from the technote "MustGather: Out of Memory Errors on Windows, Part 1"
 
Resolving the problem
This is the second step in gathering troubleshooting data when there is evidence of a memory leak. MustGather: Out of Memory exceptions on Windows, Part 1 is a prerequisite, since it helps you decide if this technote is necessary.
If you already contacted support, continue to the component-specific MustGather information. Otherwise, click the following link: MustGather: Read first for all WebSphere Application Server products.


Out of Memory (Java heap) specific MustGather information
Set up for enabling heap dump file generation:
  • For releases of V6.0:
    1. To set the Environment Entries from the administrative console, select the following:

      Servers > Application Servers > server_name > Java and Process Management > Process Definition > Environment Entries > New

    2. Add the following Name and Value pairs:

      Name Value
      IBM_HEAPDUMP true
      IBM_HEAP_DUMP true
      IBM_HEAPDUMPDIR your_directory
      IBM_HEAPDUMP_OUTOFMEMORY true
      IBM_JAVADUMP_OUTOFMEMORY true
      IBM_JAVA_HEAPDUMP_TEXT true


    3. Make sure that you save changes to the master configuration.

  • For release V5.1.1:
    1. To set the Environment Entries from the administrative console, select the following:

      Servers > Application Servers > server_name > Process Definition > Environment Entries > New

    2. Add the following Name and Value pairs:
      Name Value
      IBM_HEAPDUMP true
      IBM_HEAP_DUMP true
      IBM_HEAPDUMPDIR your_directory
      IBM_HEAPDUMP_OUTOFMEMORY true
      IBM_JAVADUMP_OUTOFMEMORY true
      IBM_JAVA_HEAPDUMP_TEXT true

    3. Make sure that you save changes to the master configuration.

    For releases of V5.0 and V5.1.0:
    1. To set the Environment Entries from the administrative console, select the following:

      Servers > Application Servers > server_name > Process Definition > Environment Entries > New

    2. Add the following Name and Value pairs:
      Name Value
      IBM_HEAPDUMP true
      IBM_HEAP_DUMP true
      IBM_HEAPDUMPDIR your_directory
      IBM_HEAPDUMP_OUTOFMEMORY true
      IBM_JAVADUMP_OUTOFMEMORY true

    3. Make sure that you save changes to the master configuration.
  • For releases of V4.0:
    1. To enable the heap dump, add the following lines to the top of the adminserver.bat file in the install_root/bin directory, after the call to setupCmdLine.bat:

      call "%~dp0setupCmdLine.bat"
      set IBM_HEAPDUMP=true
      set IBM_HEAP_DUMP=true
      set IBM_HEAPDUMP_OUTOFMEMORY=true
      set IBM_JAVADUMP_OUTOFMEMORY=true
      set IBM_HEAPDUMPDIR=
      directory_path

    2. When you start the administrative server, use the modified adminserver.bat file from a command prompt instead of using the Services panel.

  • For releases of V3.5:
    1. To enable the heap dump, add the following lines to the adminserver.bat file in the install_root/bin/debug directory, after the call to setupCmdLine.bat:

      call "%~dp0setupCmdLine.bat"
      set IBM_HEAPDUMP=true
      set IBM_HEAP_DUMP=true
      set IBM_HEAPDUMP_OUTOFMEMORY=true
      set IBM_JAVADUMP_OUTOFMEMORY=true
      set IBM_HEAPDUMPDIR=
      directory_path

    2. When you start the administration server, use the modified adminserver.bat file from a command prompt instead of using the Services panel.

  • Notes:
    • The heap dump is written to the current directory, install_root/bin, or the directory specified by the IBM_HEAPDUMPDIR environment variable.

    • The file that is generated is called heapdumppid.time in internal format txt. This file can be very large; allow for at least the maximum heap size. If the maximum heap is set to 512 MB, allow for .5 GB for the dump.

    • Any version of WebSphere Application Server that is using the IBM JDK 1.3.1 SR5 or higher, and 1.4.X, will automatically generate heapdump and javacore files on an OutOfMemory condition. Adding the additional parameters will give you the option to manually generate heapdumps and also specify the directory in which to write the heapdump files. To manually generate heapdumps you will need to issue the WSADMIN command to generate javacore*.txt file. This will also produce a heapdump*.txt file.

When failure occurs:
  1. This mechanism uses the same signal handler as javacore processing, so do not have DISABLE_JAVADUMP set as an environment variable.

  2. Follow instructions on enabling verbosegc in WebSphere Application Server.

  3. Delete all Application Server and FFDC log files, if possible. Back them up, if needed.

  4. Restart the Application Server.

  5. Wait for the OutOfMemoryError condition to occur. This should cause the generation of a heapdump.

  6. If you want to analyze the heapdump yourself, follow instructions to use IBM HeapAnalyzer tool for analyzing JVM heap usage. If you do not want to analyze this yourself, proceed to step 8.

  7. Collect the following files:
    • For releases of V6.0:
      • The server.xml file located in the following directory:

        install_root\profiles\profile_name\config\cells\
        cell_name
        \nodes\node_name\servers\server_name

      • Everything in the following directory:

        install_root\profiles\profile_name\logs\server_name

        Specifically, the following logs are needed:
        • systemErr
        • systemOut
        • native_stderr
        • native_stdout
        • heapdump*.txt or heapdump*.phd
        • javacore*.txt

      • Everything in the following directory:

        install_root\profiles\profile_name\logs\ffdc

      • All documents requested For all releases below.

    • For releases of V5.0 and V5.1:
      • The server.xml file located in the following directory:

        install_root\config\cells\nodes\node_name\servers\server_name

        Specifically, the following logs are needed:
        • systemErr
        • systemOut
        • native_stderr
        • native_stdout
        • heapdump*.txt or heapdump*.phd
        • javacore*.txt

      • Everything from the following directory:

        install_root\logs\server_name

      • Everything from the following directory:

        install_root\logs\ffdc

      • All documents requested For all releases below.

    • For releases of V4.0 and V3.5:
      • A XMLConfig full export.

      • Everything from the following directory:

        install_root\logs

        Specifically, the following log files are needed:
        • stderr
        • stdout
        • tracefile
        • heapdump*.txt
        • javacore*.txt

      • All documents requested For all releases below.

    • For all releases
      • All javacore*.txt files that were created when OutOfMemory conditions occurred. If javacore*.txt files were created, you can find them in the install_root, install_root\bin or in the configured working directory.

      • Include the Application Server systemErr, systemOut, native_stderr, and native_stdout logs, if they are located in a different directory.

      • List of all other software and version information on the system. For example, any databases, WebSphere MQ®, and so forth.

  8. Follow instructions to send diagnostic information to IBM support.

Notes:
  • JVM heap dump generation on OutOfMemory are enabled by default startng from IBM JDK 1.3.1 SR5 and in all of the IBM JDK 1.4.X releases. However, IBM recommends that you enable JVM HeapDumps settings for all IBM JDK releases so that you can control where JVM heap dump is written.

  • For a listing of all technotes, downloads, and educational materials specific to the Out of Memory component, search the WebSphere Application Server support site.
 
Related information
MustGather:Out of Memory Errors on Windows -Part 1
How to enable verbosegc in WebSphere
HeapRoots Tool for Analyzing JVM Memory Usage
Submitting information to IBM support
Steps to getting support
MustGather: Readme first
Troubleshooting guide
 
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Out of Memory
Operating system(s): Windows
Software version: 6.0
Software edition:
Reference #: 1140641
IBM Group: Software Group
Modified date: Aug 23, 2005