IIS simultaneous requests limit

Question

IIS 7 on Vista has a limit for concurrent requests (up to 10). I have a Virtual PC on my Vista with Windows Server 2008 installed on it. IIS 7 on the virtual PC still limits simultaneous requests. When I run the same application on ASP.NET Development Server, it's ok - there are no limits.

Is the problem in host OS? How can I tune IIS to process more concurrent requests? It's a must for application because it should handle a lot of concurrent open connections and requests connected with them.

UPD: i've noticed a difference between running app under Vista itself and under the virtual PC.

When running on Vista there is a request limit (10). If there are already 10 long-running requests the following requests hang (they are in a request queue).

When running on the virtual machine something strange happens. I have only 2 long-running requests completed. The following requests (even not long-running) are blocked.

For this test i used self-written load testing script. It pushes a lot of requests at a time.

Any ideas? How to test the app on IIS?

Answer 1

I will say the most likely culprit is Microsoft restricting the number of simultaneous inbound connections to their consumer-grade operating systems. We can't have you using them as servers, now! :)

Are you getting 500 Server Busy error on your virtual server, or are requests being rejected at the network level? The answer to that will answer your question.

Answer 2

The requests are not rejected - they are placed in a queue for processing. So the client just hangs waiting for the response

Hi, did you find a solution to this problem, i have same exact problem. Flash video on a page, while the flash is playing (downloading) other requests can't get through. When the download is complete other requests work again. Any insight would be appriciated.