My Web site is defined with an application pool which supports up to 4 worker process. So, this makes 4 w3wp.exe in the Task Manager. They are not loaded immediately at first. But, once needed, they will eventually be all loaded.

So, in full production, the four worker process are loaded and seen in the Task Manager. When I look at my hit table, which contains a ProcessID field, I can also see which worker process handles which request.

The default in application pool for the worker process in queue is 1000. So, it means, a worker process can queue up to 1000 hits.

So, I would like to verify one thing again in regards to this. Is this really the case that if a worker process is busy processing a hit, then the application pool will forward to the next available worker process. Then, if all four worker process are busy, a queue will start. Assuming this, it would then mean that a worker process can only process one hit at a time. When finish, it there is a queue, it will immediately start processing the pending hit. Is that correct?