Enabling HTTP Traces 

Use

You can enable the tracing of HTTP requests and responses processed by the J2EE Engine. Using the different options you can configure the level of detail of the information that is traced (for example, full requests and responses or just the corresponding headers), as well as the format the information is saved in.

To configure HTTP requests and response tracing, you use the HttpTrace, HttpTraceTime,  LogResponseTime, and TraceResponseTimeAbove properties of the HTTP Provider Service.

Enabling the HTTP tracing can result in security-sensitive data being written to the corresponding trace files. Therefore, SAP recommends using this function for debugging purposes on non-productive systems, or on debug nodes if the system is productive! For more information, see Security Aspects When Using HTTP and Web Container Tracing. 

Destination File for HTTP Traces

For destination files of the saved traces, see each procedure below.

You can use the Log Viewer to view the messages in trace files.

Procedure

Tracing Full Requests and Responses

       1.      Using the Visual Administrator tool, open the Properties tab of the HTTP Provider Service running on the dispatcher.

       2.      Assign the appropriate value to the HttpTrace property. You have the following options:

Value	Behavior
enable	The full requests and responses are traced in plain text format. If you expect that the responses to be traced contain gzip compressed content, or non-ASCII symbols (for example, when transferring binaries like images, archived files, and so on), we recommend that you use tracing in hexadecimal format by setting the HttpTrace property to enableHex.
enableHex	The full requests and responses are traced in hexadecimal format.
enableHeaders	Only the request and response headers are traced. Information is saved in plain text format.
enableHexHeaders	Only the request and response headers are traced. Information is saved in hexadecimal format.
disable	No information is traced at all. In this case, HTTP communication errors (such as problems with sockets, ports and so on) are still traced in the defaultTrace.trc file of the dispatcher.

Enabling the HTTP tracing using the HttpTrace property logs messages with severity INFOby default. If you need more detailed messages, you have to increase the severity of the com.sap.engine.services.httpserver.dispatcher.Processor location to DEBUG or ALL. For more information, see Adding, Editing, and Removing Log Controllers.

       3.      To add the new value to the list of properties, choose Update.

       4.      To add the time (in milliseconds) for which the request is served to the information that is traced, set the HttpTraceTime property to true. This only works if the HttpTrace property has a value other than disable.

The time for which the request is served is measured from the moment the request is accepted on the dispatcher to the moment when the whole response is sent back to the client.

       5.      To add the new value to the list of properties, choose Update.

       6.      To save your settings, choose  (Save Properties). You can view the traces in the  \usr\sap\<SID>\<instance_name>\j2ee\cluster\dispatcher\log\services\http\req-resp.trc file.

Tracing Dispatcher Response Times

...

       1.      Using the Visual Administrator tool, open the Properties tab of the HTTP Provider Service running on the dispatcher.

       2.      Enable the HttpTraceTime property.

       3.      To save your settings, choose  (Save Properties). You can view the traces in the \j2ee\cluster\server<x>\log\system\httpaccess\responses.0.trc file.

Tracing Server Response Times

...

       1.      Using the Visual Administrator tool, open the Properties tab of the HTTP Provider Service running on the server.

       2.      Enable the LogResponseTime property.

       3.      To save your settings, choose  (Save Properties). You can view the traces in the \j2ee\cluster\server<x>\log\system\httpaccess\responses.0.trc file.

Tracing Requests with Response Times Above a Given Time Period

...

       1.      Using the Visual Administrator tool, open the Properties tab of the HTTP Provider Service running on the server.

       2.      To specify if additional traces are written to the default trace file, assign the appropriate value to the TraceResponseTimeAbove property. You have the following options:

Value ( set in milliseconds)	Behavior
-1	No additional traces.
> -1	Additional traces are written to the default trace file only for requests that have response times in milliseconds equal to, or higher than the specified value.

       3.      Set the log severity of the HTTP Provider Service to DEBUG.

       4.      To save your settings, choose  (Save Properties). You can view the additional traces in the \j2ee\cluster\server<x>\log\defaultTrace.<n>.trc file.