Diagnostic trace service settings: WebSphere Application Server

Use this page to review and modify the properties of the diagnostic trace service.

To view this page, click Troubleshooting > Logs and Trace > server > Diagnostic trace.

Configuration tab

Enable Trace

Enables the trace service.

If this option is not selected, the following configuration properties are not passed to the application server trace service at server startup.

Trace Specification

Specifies tracing details.

Enter a trace string that specifies the components, packages, or groups to trace. The trace string must conform to the specific grammar described below. You can enter the trace string directly, or generate it using the graphical trace interface. Click Modify to start the graphical trace interface.

If you start the graphical trace interface from the configuration tab, a list of well-known components, packages, and groups is displayed. This list might not be exhaustive.

If you start the graphical trace interface from the runtime tab, the list of components, packages, and groups displays all such components currently registered on the running server.

The format of the trace specification is:

<component> = <trace_type>= enabled | disabled

where: <component> is the component for which to enable or disable tracing, and <trace_type> is the type of tracing to enable or disable. Separate multiple tracing specifications with colons (:).

Components correspond to Java packages and classes, or to collections of Java packages. Use * as a wildcard to indicate components that include all classes in all packages contained by the specified component. For example:

*: Specifies all traceable code running in the application server, including WebSphere Application Server system code and customer code.
com.ibm.ws.*: specifies all classes whose package name begins with com.ibm.ws.
com.ibm.ws.classloader.JarClassLoader: Specifies only the JarClassLoader class.

For more information on trace string grammar, see the article Enabling trace in the WebSphere Application Server InfoCenter.

Note: An error can occur when setting a trace specification from the adminstrative console if selections are made from both the Groups and Components lists. In some cases, the selection made from one list is not lost when adding a selection from the other list. To work around this problem, enter the desired trace specification directly into the Trace Specification entry field.

Trace Output

Specifies where trace output should be written.

The trace output can be written directly to an output file, or stored in memory and written to a file on demand using the Dump button found on the runtime page.

Memory Buffer

Specifies that the trace output should be written to an in-memory circular buffer. If you select this option specify the following parameters:

Maximum Buffer Size: Specifies the number of entries, in thousands, that can be cached in the buffer. When this number is exceeded, older entries are overwritten by new entries.
Dump File Name: The name of the file to which the memory buffer will be written when it is dumped. This option is only available from the runtime tab.

File: Specifies to write the trace output to a self-managing log file.
The self-managing log file writes messages to the file until a size criteria is reached. When the file reaches the specified size, logging is temporarily suspended and the log file is closed and renamed. The new name is based on the original name of the file, plus a timestamp qualifier that indicates when the renaming occurred. Once the renaming is complete, a new, empty log file with the original name is reopened, and logging resumes. No messages are lost as a result of the rollover, although a single message may be split across the two files.

If you select this option specify the following parameters:

Maximum File Size: Specifies the maximum size, in megabytes, to which the output file is allowed to grow.
This attribute is only valid if the File Size attribute is selected. When the file reaches this size, it is rolled over as described above.
Maximum Number of Historical Files: Specifies the maximum number of rolled over files to keep.
File Name: Specifies the name of the file to which the trace output is written.

Trace Output Format

Specifies the format of the trace output.

You can specify one of three levels for trace output:

Basic (Compatible): Preserves only basic trace information. Select this option to minimize the amount of space taken up by the trace output.
Advanced: Preserves more specific trace information. Select this option to see detailed trace information for use in troubleshooting and problem determination.
Log Analyzer: Preserves trace information in a format that is compatible with the Log Analyzer tool. Select this option if you want to use the trace output as input to the Log Analyzer tool.

Runtime tab

Save Trace

Save changes made on the runtime tab to the trace configuration as well.

Select this box to copy runtime trace changes to the trace configuration settings as well. Saving these changes to the trace configuration will cause the changes to persist even if the application is restarted.