Enable trace on a running server
Use the administrative console to enable tracing on a running server. We can use trace to assist you in monitoring system performance and diagnosing problems.
We can modify the trace service state that determines which components are being actively traced for a running server by using the following procedure.
We can also configure tracing from the MVS™ console using the modify command.
This topic references one or more of the application server log files. As a recommended alternative, we can configure the server to use the High Performance Extensible Logging (HPEL) log and trace infrastructure instead of using SystemOut.log , SystemErr.log, trace.log, and activity.log files on distributed and IBM i systems. We can also use HPEL in conjunction with the native z/OS logging facilities. If we are using HPEL, we can access all of the log and trace information using the LogViewer command-line tool from the server profile bin directory. See the information about using HPEL to troubleshoot applications for more information on using HPEL.
- Start the administrative console.
Click Troubleshooting > Logs and Trace in the console navigation tree, then click server > Diagnostic Trace.
- Select the Runtime tab.
- Select the Save runtime changes to configuration as well check box to write the changes back to the server configuration.
- Change the existing trace state by changing the trace specification to the desired state. Refer to the following topics for specific information on how to change the trace specifications:
- "Diagnostic trace service settings" describes how we can examine the current diagnostic trace settings and to change where the trace is written (memory buffer or file). If the trace is to be recorded in a memory buffer, we can specify the file to which the memory buffer is to be dumped. We can view the file for trace information.
- "Log and trace settings" describes how we can view and configure logging and trace settings for the server.
- "Managing the application server trace service" describes how we can manage the trace service for a server process while the server is stopped and while it is running. We can specify which components to trace, where to send trace output, the characteristics of the trace output device, and which format to generate trace output in. We can select where the trace is written (memory buffer or file).
The clauses included in a trace specification are read in the order they appear in the string. If multiple variations of the *=info clause are included in a trace specification, the last value specified is the value that determines the trace level that the system logs. If specified *=info as the last clause, tracing occurs at the info level regardless of other clauses specified in the trace string. For example, if specified the following trace string:
*=info:PMGR=all:*=info:com.ibm.ws.sm.*=all
is equivalent to simply specifying:
*=all
Because the final clause overrides all clauses that were specified ahead of it in the string.gotcha
On an application server, trace output can be directed either to a file or to an in-memory circular buffer. If trace output is directed to the in-memory circular buffer, it must be dumped to a file before it can be viewed.
On an application client or stand-alone process, trace output can be directed either to a file or to the process console window.
- Configure the trace output if a change from the existing one is desired.
- Click Apply.
Related tasks
Enable trace at server startup Turning traces on and off in servers processes Configure traces Tracing operations using wsdmin.sh Use High Performance Extensible Logging to troubleshoot applications
Modify command