Enable trace on client and stand-alone applications

When stand-alone client applications (such as Java applications which access enterprise beans hosted in WebSphere Application Server) have problems interacting with WebSphere Application Server, it might be useful to enable tracing for the application. Enable trace for client programs will cause the WAS classes used by those applications, such as naming-service client classes, to generate trace information.

A common troubleshooting technique is to enable tracing on both the application server and client applications, and match records according to timestamp to try to understand where a problem is occurring.

We can also configure tracing from the MVS™ console using the modify command.

1. To enable trace for the WAS classes in a client application, add the system properties shown in the following example to the startup script or command of the client application. The location of the output and the classes and detail included in the trace follow the same rules as for adding trace to WebSphere Application Servers. For example, trace the stand-alone client application program named com.ibm.sample.MyClientProgram, enter the following command:
   java -DtraceSettingsFile=MyTraceSettings.properties -Djava.util.logging.manager=com.ibm.ws.bootstrap.WsLogManager -Djava.util.logging.configureByServer=true com.ibm.samples.MyClientProgram

   The file identified by file name must be a properties file placed in the class path of the application client or stand-alone process. Create a trace properties file by copying the %install_root\properties\TraceSettings.properties file to the same directory as the client application JAR file.

   The file identified by file name must be a properties file placed in the class path of the application client or stand-alone process. Create a trace properties file by copying the app_server_root/properties/TraceSettings.properties file to the same directory as the client application JAR file

   We cannot use the -DtraceSettingsFile=TraceSettings.properties property to enable tracing of the ORB component for thin clients. ORB tracing output for thin clients can be directed by setting com.ibm.CORBA.Debug.Output = debugOutputFilename parameter in the command line.

   The java.util.logging.manager and java.util.logging.configureByServer system properties configure Java logging to use a WAS-specific LogManager class and to use the configuration from the file specified by the traceSettingsFile property. The default Java Logging properties file, located in the Java SE Runtime Environment 6 (JRE6), will not be applied.

2. We can configure the MyTraceSettings.properties file to send trace output to a file using the traceFileName property. Specify one of two options:

   • The fully qualified name of an output file. For example, traceFileName=c:\\MyTraceFile.log. Specify this property to generate visible output.

   • stdout. When specified, output is written to System.out.

3. We can also specify a trace string for writing messages with the Trace String property, Specify a startup trace specification similar to that available on the server. For your convenience, we can enter multiple individual trace strings into the trace settings file, one trace string per line.

Results

Here are the results of using each optional property setting:

• Specify a valid setting for the traceFileName property without a trace string to write messages to the specified file or System.out only.

• Specify a trace string without a traceFileName property value to generate no output.

• Specify both a valid traceFileName property and a trace string to write both message and trace entries to the location specified in the traceFileName property.

Related tasks

Enable trace at server startup

Enable trace on a running server

Manage the application server trace service

Modify command