Tracing web services
We can trace the web services runtime 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 runtime components. We can also trace user-defined exceptions and SOAP messages that use Java Message Service (JMS) or HTTP to request web services.
To trace the web services run time only:
See step 4 for settings we can use to trace user-defined exceptions and SOAP messages or review the tracing SOAP messages with tcpmon documentation.
The following tasks describe how we can enable trace for web services:
- Enable trace for a web services unmanaged client.
- Create a trace properties file by copying the %install_root\properties\TraceSettings.properties file to the same directory as the client application Java archive (JAR) file.
- (iSeries) Create a trace properties file by copying the app_server_root/properties/TraceSettings.properties file to the same directory as the client application Java archive (JAR) file.
- Edit the properties file and change the traceFileName value to output the trace data. For example, traceFileName=c:\\temp\\myAppClient.trc.
- (iSeries) Edit the properties file and change the traceFileName value to output the trace data. For example, traceFileName=/myDir/myAppClient.trc.
- Edit the properties file to remove com.ibm.ejs.ras.*=all=enabled and add com.ibm.ws.webservices.engine.*=all=enabled.
- Add the -DtraceSettingsFile=<trace_properties_file> option to the java command line used to run the client, where trace_properties_file represents the name of the properties file that we created in the substeps a through c. For example, java -DtraceSettingsFile=TraceSettings.properties myApp.myAppMainClass.
- Enable trace for a web services-managed client by invoking the launchClient command-line tool with the following options:
- Enable trace for a Web Services for Java EE server application.
- Start WebSphere Application Server.
- Open the administrative console.
- Click Servers > Application Servers > server.
- Click Change Log Detail Levels.
- 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. We must separate each trace string by a colon (:) with no spaces. For example:
- Choose a predefined trace string from the section 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, to add a predefined trace string for the SOAP messaging trace, we can click: com.ibm.ws.webservices.trace.MessageTrace.
- Click the trace option from the drop-down list. For example, we can choose off, fatal, severe, warning, audit, info, config, detail, fine, finer, finest, and all. The option, finest, is recommended. When we click on the option, the option is added to the end of the trace string. For example:
- Click Save and Apply.
To learn more about enabling trace, see the tracing and logging configuration information.
- Enable trace for SOAP messages, user-defined exceptions, or both. The following trace specifications are used to trace SOAP messages:
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.
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 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.
IBM recommends configuring the server to use the High Performance Extensible Logging (HPEL) log and trace infrastructure . We view HPEL log and trace information using the logViewer .
We can also use the following trace strings to enable tracing for user-defined exceptions, as well as other trace points:
Turns on all web services run-time trace logs.
Turns on MessageTrace and UserExceptionTrace.
Please note once this trace is turned on, the whole SOAP message payload will be written into trace file. If there is any confidential information (such as user ID or password) in the SOAP message as part of the payload, they will be output as plain text as well. Please properly plan to protect the security of our information.
For JAX-WS web service, there are two ways (normal level and minimal level) to print out both the Outbound HTTP SOAP message and the Inbound HTTP SOAP message in the trace file.
- Normal level by setting
- Minimal level by setting
We have enabled trace for the unmanaged clients, managed clients, and the server applications. Depending on the trace string specification, the trace can include runtime components, user-defined exceptions and SOAP messages.
What to do nextAnalyze the message data.
Troubleshoot web services Tracing SOAP messages with tcpmon Use High Performance Extensible Logging to troubleshoot applications launchClient tool