Microsoft has published a new technical whitepaper: Instrumentation Best Practices for High Performance BizTalk Solutions.
Definitely worth a read if you write BizTalk apps. For best performance, they recommend leveraging ETW which is the Event Tracing for Windows infrastructure. This can be accessed via the Microsoft.BizTalk.Diagnostics.TraceProvider class. Apparently performance trumps System.Diagnostics.Trace, EntLib5 Tracing, and Log4Net Tracing.
Sample source code can be downloaded here.
ETW has been around since Windows Server 2000 and did get mention at this year’s Tech Ed Europe so is worth getting up to speed with.