Tracing in ASP.NET

ASP.NET tracing enables you to view diagnostic information about a single request for an ASP.NET page. ASP.NET tracing enables you to follow a page's execution path, display diagnostic information at run time, and debug your application. ASP.NET tracing can be integrated with system-level tracing to provide multiple levels of tracing output in distributed and multi-tier applications.

ASP.NET tracing offers the following features:

Debugging statments You can write debug statements in your code without having to remove them from your application when it is deployed to production servers. You can also write variables or structures in a page and trace through the execution path of your page or application.

Integrated tracing functionality You can route messages emitted by the System.Diagnostics..::.Trace class to ASP.NET tracing output, and route messages emitted by ASP.NET tracing to System.Diagnostics..::.Trace. You can also forward ASP.NET instrumentation events to System.Diagnostics..::.Trace. For more information, see Walkthrough: Integrating ASP.NET Tracing with System.Diagnostics Tracing.

Programmatic access to trace messages You can access and manipulate trace messages from your code for finer control over the format of trace messages or for additional processing that you require.

Application-level tracing The application-level tracing option lets you view the most recent tracing data available without restarting a tracing session and without increasing the amount of tracing data that the server must store. The most recent tracing data is displayed, and older tracing data is discarded.

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http://msdn.microsoft.com/en-us/library/bb386420.aspx