I am hosting a ASP.NET WEB API application on IIS 8. In our setup we have two Webservers. The way setup is designed, all the request hits a primary server (call it Server A) and then it simply redirects every request to our server (call it Server B) which is actually hosting ASP.NET WEB API application. All this was working fine for an year but yesterday suddenly it seems Server B decided to block every incoming request from Server A. During this time, if we directly access Server B, it was still serving data.
I looked at the IIS logs for the web site and there is absolutely no logs about the duration at which IIS was not responding. Event logs are also empty.
I looked at the CPU and Memory utilization on Server B and it not high.
I will enable failed request trace on IIS now. But I am hoping meanwhile I can find some answers to this issue.