So, you’ve got Health and Activity Tracking (HAT) to look at the messages and orchestrations inside your BizTalk server, but typically you want more application level logging in the real world.

The Enterprise Instrumentation Framework (EIF) is a fantastic way of getting diagnostics/logging on the Microsoft platform, and you can of course leverage it from BizTalk, however for simple “What’s going on?” type stuff when your debugging then you can simply use System.Diagnostics.Debug .NET class.

You can use this from within any .NET components you call as usual, but crucially you can use it within an Expression shape in BizTalk to output say Promoted parts of a Message, debugging of the path in the orchestration taken (following a decide shape, etc.).  

Just makes life that bit easier – especially considering the pain it takes to unbind,unenlist, undeploy and then deploy, bind, enlist all over again J

You then need to be able to “see” this Debug, your best bet is DebugView from SysInternals, and while I’m here check out Process Explorer it’s had some massive changes over the past few months and now has built in symbol server support and the ability to see the call stack on threads in any process – Cool!