Running BizTalk 2013r2 Enterprise Edition with CU8 on a single server group.
Scenario: I have an orchestration that's called by a parent orchestration. The child receives an "Application" message variable as a parameter, which the parent has collected from a file receive location.
Within the child orchestration, a new "Validation" message is created within an expression shape. This "Validation" message is passed to a web service via a send port.
The child orchestration then logs to a text file (using log4net), the content of "Application" message before passing it into a map.
Problem: The 1st time the orchestration runs, everything works fine. However, another "Application" message is fed into the parent orchestration (via a file drop) again within a few minutes, then something very strange happens. From the log file, I can see that the content of the "Application" message is now a copy of that of the "Validation" message. Subsequently, the map fails because it's expecting to receive an "Application" message, not a "Validation" message.
Troubleshooting: The 2nd application message need not have the same content as the first in order the the problem to occur. The trigger is time dependent rather than dependent on the message content.
The problem occurs only if the 2nd Application message is fed into BizTalk within a "few minutes" of the 1st. However, even if I ensure that the 1st parent orchestration instance has completed - by checking the Active Instances from the BizTalk admin console, the problem occurs.
Restarting the host instance of the orchestrations (same host instance for both), or waiting a long time (more that 5 mins) resolves the the problem.
Any ideas?