Setting up a trace in WebSphere Application Server

Troubleshooting

https://www.ibm.com/support/pages/setting-trace-websphere-application-server

Problem

Use this document to set up trace strings for IBM WebSphere Application Server as mentioned in the component-specific MustGather documents.

Resolving The Problem

Note, the trace string you use depends on what module or component in WebSphere Application Server you need to trace, or what problem you are wishing to troubleshoot. Trace file Maximum file size and the Maximum number of historical files suggested is sufficient for most cases. For large environment set Maximum number of historical files to 30(captures 3gb trace approx).

To determine which trace string you need, go to MustGather: Read first for WebSphere Application Server for a listing of product components that matches your symptom.

For WebSphere Application Server V8.5 Liberty profile, use Setting up trace and getting a full dump in the WebSphere Application Server V8.5 Liberty profile

Static trace:

Log on to the administrative console.
In left panel expand Troubleshooting. Click on Logs and Trace.
Select the application server to be traced, and then on the next page click the Diagnostic Trace link.
Select the Configuration tab.
Under Trace Output, select File radio button and specify File Name. Also Increase the Maximum file size to 100 MB and Increase the Maximum number of historical files to 10.
Select Basic (Compatible) Trace Output Format unless otherwise specified by support.
On same panel click on Change Log Detail Levels under Additional Properties on right side panel.
Under Configuration tab specify Trace Specification by entering the trace string specific to the MustGather documentation for which you are collecting data.
Click Apply and OK. Then Save your configuration (select Synchronize changes with Nodes option)
Restart the server to begin tracing.

Dynamic trace:

Log on to the administrative console.
In the left panel, expand Troubleshooting and click on Logs and Trace.
Select the application server to be traced, and then on the next page click the Diagnostic Trace link.
Select the Runtime tab (Server should be up and running for this tab to show up).
Under Trace Output, select File and type a File name (if you do not specify path, but just the file name, then the default location of the file is under the application server profile directory). Set the Maximum File size to 100Mb and Maximum Number of historical files to 10.

Important: Do not select Save Runtime Changes to Configuration as well if you do not want this setting to become permanent.
On same panel click on Change Log Detail Levels under Additional Properties on right side panel.
Select the Runtime tab.
Under Trace Specification, enter trace string for the specific MustGather for which you are collecting data.
Click Apply and OK. Then Save your configuration (select Synchronize changes with Nodes option).
Server does not require a restart.

Stopping trace:

Remove the trace string from Trace Specification in the appropriate trace tab(s) (Configuration and/or Runtime).
Click Apply and OK. Then Save your configuration (select Synchronize changes with Nodes option).