I have just set up a web farm with Application Request Routing on IIS 8.5, with Load Balance connecting to two servers. The static page HelloWorld.html and the first login page looks fine. However when the submit button is hit, whenever a code behind is involved it takes a long time to load. I've modified the timeout value from 30s to 300s, then it loads for a few minutes and gave me a

502 - Web server received an invalid response while acting as a gateway or proxy server.

I've enabled trace log but not sure where can I find the exact problem. In the summary it's showing


ModuleName ApplicationRequestRouting


HttpStatus 502

HttpReason Bad Gateway

HttpSubStatus 3

ErrorCode 2147954430


ErrorDescription The connection with the server was terminated abnormally

Anyone had similar experience and is able to give me a hint?

  • Hi, I am having the same issue. Did you manage to solve this? Thanks – albattran Feb 10 '17 at 5:34
  • I found it's a probem in Session State Management. Check out the following links and see if that helps your situation. msdn.microsoft.com/en-us/library/ms972338.aspx and dotnetcodr.com/2013/07/01/… – ydoow Feb 10 '17 at 5:52
  • Thanks for getting back to me, we did not use sessions so that was not the issue. We have managed to solve the problem, I added our solution as an answer below. – albattran Feb 11 '17 at 23:21

I have discovered that the problem we had was due to a conflict between ARR and ASP.net MVC running on the same site.
It turns out, that if you process request parameters for whatever reason in your main site (e.g. filters, or global.asax) it will clear out the post parameters in the request sent by ARR, and hence resulting in a timeout.

You can solve it in one of two ways as follows.

  1. Put ARR in a separate process (if you can)
  2. Or make sure whatever filter you have checks the path being used in ARR and avoid touching the request parameters.

Not sure if this is the same issue you were having but I am putting here as an answer if someone else had the same problem as I did, with similar symptoms to you.

  • Any idea if you can put ARR in a separate process? I couldn't seem to. – Marcus Oct 26 '17 at 9:03
  • I think you can do that if you have different application pool, and don't inherit your webconfig, I could be wrong though – albattran Oct 27 '17 at 15:00

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.