Tracing Web services

We can trace the Web services run-time components, including an unmanaged client, a managed client and a server application. The procedure entry and exit, as well as the processing actions are traceable in the run-time components. We can also trace user-defined exceptions, as well as SOAP messages that use Java Message Service (JMS) or HTTP to request Web services.

 

Before you begin

The com.ibm.ws.webservices.engine.*=all=enabled specification traces the Web services run time only. See step 4 for settings that one can use to trace user-defined exceptions and SOAP messages or review Tracing SOAP messages with tcpmon to learn about tracing SOAP messages with the tcpmon process.

 

Overview

The following tasks describe how one can enable trace for Web services:

 

Procedure

  1. Enable trace for a Web services unmanaged client.

    1. Create a trace properties file by copying the %install_root\properties\TraceSettings.properties file to the same directory as your client application JAR file.

    2. Edit the properties file and change the traceFileName value to output the trace data. For example, traceFileName=c:\\temp\\myAppClient.trc.

    3. Edit the properties file to remove com.ibm.ejs.ras.*=all=enabled and add com.ibm.ws.webservices.engine.*=all=enabled.

    4. Add the -DtraceSettingsFile=<trace_properties_file> option to the Java command line that is used to run the client, where trace_properties_file represents the name of the properties file that you created in the substeps a through c. For example, java -DtraceSettingsFile=TraceSettings.properties myApp.myAppMainClass.

  2. Enable trace for a Web services-managed client by invoking the launchClient command-line tool with the following options:

    -CCtrace=com.ibm.ws.webservices.engine.*=all=enabled

    -CCtracefile=traceFileName For example:

    %install_root%\bin\launchClient MyAppClient.ear
    

    -CCtrace=com.ibm.ws.webservices.engine.*=all=enabled -CCtracefile=myAppClient.trc
    
    See launchClient tool for more information.

  3. Enable trace for a Web Services for Java 2 enterprise edition (J2EE) server application.

    1. Start WebSphere Application Server.

    2. Open the administrative console.

    3. Click Servers > Application Servers > server.

    4. Click Change Log Detail Levels.

    5. Add or delete the trace string in the text box. For this task, delete the trace string *=info and add the trace string com.ibm.ws.webservices.engine.*=all=enabled. We can specify the trace string in the text box in one of two ways:

      • Type the trace string directly into the text box. You must separate each trace string by a colon (:) with no spaces. For example

        com.ibm.ws.webservices.trace.MessageTrace=finest:com.ibm.ws.webservices.
        engine.Message=finest
        

      • Choose a predefined trace string from the section that is listed. The predefined section starts with *[All Components]. The predefined tracing strings Web services component are listed under the com.ibm..ws.* section.

        • Click the plus (+) sign to expand the com.ibm.ws.* section.

        • Click the predefined trace string. For example, if you want to add a predefined trace string for the SOAP messaging trace, one can click: com.ibm.ws.webservices.trace.MessageTrace.

        • Click the trace option from the drop-down list. For example, one can choose off, fatal, severe, warning, audit, info, config, detail, fine, finer, finest, and all. The option, finest, is recommended. When you click on the option, the option is added to the end of the trace string. For example

          com.ibm.ws.webservices.trace.MessageTrace=finest
          

    6. Click Save and Apply.

    For more information see, Enabling trace.

  4. Enable trace for SOAP messages, user-defined exceptions, or both. The following trace specifications are used to trace SOAP messages:

    • com.ibm.ws.webservices.trace.MessageTrace=all

      This specification traces the contents of a SOAP message, including the binary attachment data.

      When the context-type of the SOAP message is not text and xml, the message probably contains attachments. In this case, the message is displayed in the trace file in the hex dump format. The following example illustrates a line in the hex dump format for non-text SOAP messages

      0000: 0D 0A 2D 2D 2D 2D 2D 2D - 3D 5F 50 61 72 74 5F 36 ..------=_Part_6
      

      • In each trace file line, 16 bytes of the message are displayed

      • The first four digits are a hex number whose value is the byte offset into the SOAP message of the first byte on the line.

      • The next 16 two-digit hex numbers are the contents of each of the consecutive bytes in the message.

      • The ASCII representation of the bytes is displayed in the last 16 characters of the line, with unprintable characters that are represented by a period.

    • *=off:com.ibm.ws.webservices.*=all

      We can trace all Web services information, including the SOAP messages and the user-defined exceptions, with this setting.

    We can enable logging of user-defined exceptions by specifying the com.ibm.ws.webservices.trace.UserExceptionTrace=all trace string. The user-defined exceptions are not logged by default. A user-defined exception is an exception that is defined in the Web Services Description Language (WSDL) file for an operation.

    A user-defined exception often indicates an error-free condition. For example, the user-defined OverdrawnException exception, can occur for the service endpoint implementation of the makeWithdrawl method. This exception indicates an expected condition and does not indicate an error in the service endpoint implementation. Because these types of exceptions can occur during normal processing, they are not logged by default. When a user-defined exception is logged, the information is sent to the trace.log file and not to the SystemOut.log file.

    We can also use the following trace strings to enable tracing for user-defined exceptions, as well as other trace points:

    • com.ibm.ws.webservices.*=all

      Turns on all Web services run-time trace logs.

    • com.ibm.ws.webservices.trace.*=all

      Turns on MessageTrace and UserExceptionTrace.

 

Result

You have enabled trace for the unmanaged clients, managed clients, and the server applications. Depending on the trace string specification, the trace can include run-time components, user-defined exceptions and SOAP messages.

 

What to do next

Analyze the message data.


 

Related Tasks


Troubleshooting Web services
Tracing SOAP messages with tcpmon