My environment:
IIS 7.5 + .NET 4.5, both updated to latest hotfixs. Running on Windows 2008 Server R2(hosted on a Xen Virtual Machine)
Configuration: App.Pool never recycle, with one w3wp.exe process, HTTP connection set to 100000.
Problem:
See the graph on 13:58:45, it happens periodically, normally every 20 ~ 30 minutes, the Current Connections of Web Services rises very high, but other metrics like Get Request/Sec and BytesTotal/Sec of IIS layers goes down terribly. And ASP.NET got no request to process, when this happens we can't access the website from external client browsers, we can't access the website even from the browser on that server(namely via http://127.0.0.1/). This problems normally continues for 5 to 10 seconds. We tcpdumped the network packages, client browser do send packages to the server, and the server returns ack normally, but IIS on the server seems hangs, didn't process the network packages it received.
It really confuses us. Looking for help!
