Enable trace at server startup

Use the administrative console to enable tracing at a server's startup. We can use trace to assist you in monitoring system performance and diagnosing problems.

The diagnostic trace configuration settings for a server process determines the initial trace state for a server process. The configuration settings are read at server startup and used to configure the trace service. We can also change many of the trace service properties or settings while the server process is running.

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.

1. Start the administrative console.

2. Click Troubleshooting > Logs and trace in the console navigation tree, then click Server > Diagnostic Trace.

3. Click Servers > Application Servers > server_name > Troubleshooting > Diagnostic Trace Service.

4. Click Configuration.

5. Do not select the None check box. If this option is selected, the trace data is not logged or recorded anywhere. All other handlers (including handlers registered by applications) still have an opportunity to process these traces.

6. Select whether to direct trace output to either a file or an in-memory circular buffer.

   Different components can produce different amounts of trace output per entry. Naming and security tracing, for example, produces a much higher trace output than web container tracing. Consider the type of data being collected when you configure the memory allocation and output settings.

7. If the in-memory circular buffer is selected for the trace output set the size of the buffer, specified in thousands of entries. This is the maximum number of entries that will be retained in the buffer at any given time.

8. If a file is selected for trace output, set the maximum size in megabytes to which the file should be allowed to grow. When the file reaches this size, the existing file will be closed, renamed, and a new file with the original name reopened. The new name of the file will be based upon the original name with a timestamp qualifier added to the name. In addition, specify the number of history files to keep.

9. Select the desired format for the generated trace.

10. Save the changed configuration.

11. To enter a trace string to set the trace specification to the desired state:

    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 we specify *=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

    1. Click Troubleshooting > Logs and trace in the console navigation tree.

    2. Select a server name.

    3. Click Change Log Level Details.

    4. If All Components has been enabled, you might want to turn it off, and then enable specific components.

    5. Click a component or group name. For more information see the page on log level settings. If the selected server is not running, you will not be able to see individual component in graphic mode.

    6. Enter a trace string in the trace string box.

    7. Select Apply, then OK.

12. Allow enough time for the nodes to synchronize, and then start the server.

Related tasks

Use High Performance Extensible Logging to troubleshoot applications

Log level settings