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. Enabling trace for
client programs will cause the WebSphere Application Server classes
used by those applications, such as naming-service client classes,
to generate trace information.
About this task
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.
You can also configure tracing
from the MVS console using the modify command.
To
configure tracing with the launchClient tool, refer to the steps in
the launchClient tool topic.
Procedure
- To enable trace for the WebSphere Application Server 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. You must create
a trace properties file by copying the %install_root\properties\TraceSettings.properties file
to the same directory as your client application Java archive (JAR)
file.
You 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 WebSphere Application
Server-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 Runtime Environment
(JRE), will not be applied.
You 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.
You must specify this property to generate visible output.
- stdout. When specified, output is written
to System.out.
- You 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, you 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.