It's not possible to predict or even attempt to document what each performance counter may or may not show during a performance test of your solution. Every solution developed on BizTalk is different, and there are a multitude of reasons why you might see certain behavior during a load test (environment, hardware, message size, etc.).
However, I have included a list of common symptoms that I've seen during performance testing. I've also identified some things to check or consider when you see such behavior. Such "real-world" information is hard to come by, and this should be of great help when you are conducting testing.
During performance testing, you might suddenly see that the Orchestrations completed/sec performance counter suddenly drops off for a significant period of time in conjunction with the % Processer Time counter on the BizTalk servers.
There are a number of potential reasons for such behavior, some of which are covered in the following sections.
The most common reason for orchestrations seeming to "drop off" is that there aren't any messages awaiting processing by orchestrations. You can check this by reviewing the Host Queue-Length counter for the appropriate BizTalk host.
If the host queue isn't showing any messages, that explains why processing has dropped off. If the host queue is showing messages, however, the drop-off can be due the fact that you are not injecting ...