IIS同时请求限制

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

Virtual PC is a client virtualization software mostly used for testing, demos etc... You can installed Server OS on it, but connection limit will still apply.

IIS7 onwards requests are not rejected but just queued, so what you are seeing is expected. Load test needs to be done on a Server OS which uses Server Virtualization (hyper-v).

Answer 2

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.