Generating a core file and malloc trace on Linux systems
 Technote (troubleshooting)
 
Problem(Abstract)
Instructions for generating a core file/system libraries and malloc trace for performance problems associated with IBM® WebSphere® Application Server on a Linux® system. Gathering this information before calling IBM support will help familiarize you with the troubleshooting process and save you time.
 
Resolving the problem

Part A: Generating a core file and system libraries
  1. Refer to Crash on Linux produces no core or a truncated core to ensure that your Linux system is properly set up to produce a full core file.

  2. At the command line, run the following:

    gdb -x gdb_commands.txt [JAVA_PATH] [CORE_PATH] > gdbtrace_out.txt

    Where:
    [JAVA_PATH] is /opt/WebSphere/AppServer/java/jre/bin/exe/java
    [CORE_PATH] is the path or filename for the core file
    gdb_commands.txt is attached to this document

  3. Run the following command from the install_root/java/jre/bin directory:

    For releases of V6.1:

    jextract [CORE_PATH]
    the output filename defaults to 'corefile'.zip

    For releases of V6.0 and V5.1:

    jextract -o core.sdff [CORE_PATH]

    Where:
    core.sdff is the output file
    [CORE_PATH] is the path/filename for the core file

  4. At the command line, run the following:

    ./libsgrabber.sh [JAVA_PATH] [CORE_PATH]

    Where:
    [JAVA_PATH] is /opt/WebSphere/AppServer/java/jre/bin/exe/java
    [CORE_PATH] is the path or filename for the core file

  5. Collect the following files:
    • Any javacore*.txt files produced
    • gdbtrace_out.txt
    • core.sdff
    • core file
    • libs.tar.gz
    • /var/log/messages

Part B: Collecting malloc trace for Out of Memory (native leak)
  1. Enable tracing of native memory allocation using IBM_MALLOCTRACE and MALLOC_TRACE to create the mtrace.log file.

    Add the environment variables for native memory allocation through the administrative console following the steps in Setting environment entries in Websphere Application Server.

    Name Value
    IBM_MALLOCTRACE 1
    MALLOC_TRACE memory_log_path

    Where, memory_log_path is the following directory:
    • For WebSphere Application Server V6.0 and V6.1 releases:

      profile_root/logs/server_name/mtrace.log

    • For WebSphere Application Server V5.0 and V5.1 releases:

      install_root/logs/server_name/mtrace.log

  2. Collect the mtrace.log file.

Follow the instructions at Exchanging information with IBM Technial Support to send in the preceding documentation.
 
gdb_commands.txt libsgrabber.sh
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers Runtimes for Java Technology Java SDK
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Crash
Operating system(s): Linux
Software version: 6.1
Software edition:
Reference #: 1255223
IBM Group: Software Group
Modified date: Feb 13, 2007