I have hosted my ASP.NET web application on two application servers. And on third server, I have created a Server Farm using ARR module in IIS. The Server Farm includes two application servers. I am using "Round Robin" policy in the Load Balancing. Default URL rewrite rule is added. Both application servers are accessible and Health Test passes for both of them.
When I browse the web application using ARR web server as a host, I get the Login page as expected. If I try to browse the same thing in another browser, it shows the login page there too. I can see in "Monitoring" tool that the requests are evenly sent to two app servers by ARR. So load balancing works well so far.
However, when I enter credentials and hit login button, I get "Err_Too_Many_Redirects" error and I see large number of calls in Fiddler too.
Can anyone help here?
Note that I am not using HTTPS. If I browse my applications directly using app server IP addresses, they work perfectly. This "too many redirects" problem comes only when they are behind the ARR load balancer.
I use cookieless session in my application. IIS on ARR server used to generate new session ID for every request it encountered. So for every request, it used to generate the new session Id and that spawned new request again. So it was entering in the kind of infinite loop.
This SO question and this post gave me a clue and answer. Removing ISAPI filters (under ISAPI Filters feature) and disabling all ISAPI extensions (under ISAPI and CGI restrictions feature) in IIS where ARR is running helped me to solve this problem.