Diagnosing problems (using diagnosis tools)

Various diagnosis tools are provided to help you determine the source and impact of problems occurring in your application serving environment.

About this task

The purpose of this section is to aid you in understanding why your enterprise application, application server, or WebSphere® Application Server is not working and to help you resolve the problem. Unlike performance tuning, which focuses on solving problems associated with slow processes and non-optimized performance, problem determination focuses on finding solutions to functional problems.

Procedure

  1. If deploying or running an application results in exceptions such as ClassNotFoundException, use the Class Loader Viewer to diagnose problems with class loaders.
  2. If you already have an error message and want to quickly look up its explanation and recommended response, look up the message by expanding the Messages section of the documentation under Reference > Messages.
  3. If you are using the basic or traditional log and trace infrastructure, and need help finding error and warning messages, interpreting messages, and configuring log files, see Using basic or traditional message logs to troubleshoot applications.
  4. If you are using the High Performance Extensible Logging (HPEL) log and trace infrastructure, and need help finding error and warning messages, interpreting messages, and configuring log files, see Using High Performance Extensible Logging to troubleshoot applications.
  5. Difficult problems can require the use of tracing, which exposes the low-level flow of control and interactions between components. For help in understanding and using traces, see Working with trace.
  6. [z/OS] For help in viewing diagnostic information like dumps, error logs and CTRACE information, see Viewing diagnostic information
  7. [8.5.5.15 or later] To capture logs for intermittent problems, see Collecting troubleshooting data with diagnostic plans.
  8. [AIX Solaris HP-UX Linux Windows][IBM i] For help in using settings or tools to help you diagnose the problem, see Working with troubleshooting tools.
    Some of these tools are bundled with the product, and others are freely downloadable.
  9. To learn how to work with Diagnostic Providers, see Working with Diagnostic Providers..
  10. To find out how to look up documented problems, common mistakes, WebSphere Application Server prerequisites, and other problem-determination information on the WebSphere Application Server public website, or to obtain technical support from IBM, see Obtaining help from IBM.
  11. [AIX Solaris HP-UX Linux Windows][z/OS] The IBM Developer: Diagnosis documentation describes debugging techniques and the diagnostic tools that are available to help you solve problems with Java. It also gives guidance on how to submit problems to IBM.
  12. [IBM i] The Troubleshoot IBM Developer Kit for Java describes debugging techniques and the diagnostic tools that are available to help you solve problems with Java. It also gives guidance on how to submit problems to IBM.
  13. For current information available from IBM Support on known problems and their resolution, see the WebSphere Application Server Product support page. For last minute updates, limitations, and known problems, refer to the Release notes.
  14. Before opening a PMR or case, collect MustGather information and send it to IBM Support. See information about MustGather.