BizTalk not tracking port data
Something went wrong and we needed to recover some tracked messages from BizTalk. But I couldn't find any tracked bodies. Somebody had only gone and turned off message tracking on the Receive Port, right? No. Receive port was tracking message bodies - just nothing appearing in the BizTalkDTADB. Queue a restart of relevant host instances and the SQL agent all to no avail.
In the end we discovered that the default pipelines (e.g. XMLReceive) weren't tracking anything. This setting is accessed from the admin console, BizTalk.System / Piplines - there you can enable tracking of events - you don't need to worry about tracking bodies here, that can still be done on the port level (otherwise you'll track everything that goes through those pipelines, which you may not want).