It is usually a very important task to clean up a BizTalk mseeage box during stress testing with large amount of messages. Below are the steps to clean up the message box in order to prepare for the new test.
1. Stop all BizTalk services
2. Type “iisreset” at command line to recycle IIS service
3. Execute the stored procedure “bts_CleanupMsgbox” on your message box database
4. Execute the stroed procedure “bts_PurgeSubscriptions” on your message box database
(if the above stored procedures can't be found, go to your BizTalk installation directory, under “Schema” folder, you can find all original scripts of these stored procedures)
5. Clean up the message box log by running the backup statement similar to below
backup log msgBoxDb to disk = “yourbackupdirectory\yourbackupfile.bak' with init, stats = 5
6. Restart BizTalk services