Trace mediation primitive

Use the Trace mediation primitive to write trace messages to the server logs or to log files. The trace messages can help in developing and debugging a mediation flow.

Introduction

You can use the Trace mediation primitive to develop and debug mediation flows, and to specify trace messages to be logged to the server logs or to a file. The trace messages can contain service message object (SMO) message content and other information about the mediation flow.

The Trace mediation primitive has one input terminal (in), one output terminal (out) and one fail terminal (fail). The in terminal is wired to accept a message and the other terminals are wired to propagate a message. The input message triggers the writing of a trace message and if the tracing is successful, the out terminal propagates the original message. If an exception occurs during the processing of the input message, the fail terminal propagates the original message, together with any exception information.

Usage

You can use the Trace mediation primitive to write your own trace messages to help with developing and debugging mediation flows.

You can use the Destination property to determine where a trace message is written to: either the server system logs, the User Trace log file, or to a specified file.

You can use the Root and Message properties to specify that information from the SMO is also included in the message, so that the automatically generated exception contains dynamic information about the state of the SMO. The default value for the Message property is {0}, {1}, {2}, {3}, {4}, {5} where:

{0} is substituted with the Time Stamp value.
{1} is substituted with the SMO Message ID value.
{2} is substituted with the Mediation Name value.
{3} is substituted with the Module Name value.
{4} is substituted with the SMO part defined by the Root property XPath. By default this is the entire SMO.
{5} is substituted with the SMO Version value.

A generated trace message for the default Message and Root would, therefore, contain information such as the following:

29/04/09 15:11, 9A85B1D2-0119-4000-E000-13E4091443BC, Trace1, MyModule, 
		<?xml version="1.0" encoding="UTF-8"?><smo>...</smo>, 6

You can use the Enabled property to determine whether the Trace primitive is mediated and is promotable, so that tracing can be switched off at run time.