after some time with lots of connections, client gets stuck requiring a full IIS reset

Bug reporter can reproduce this issue in production, but has not been able to reproduce it in test environment. From the bug reporter:

"once we get lots of connections to the live server with a single instance it eventually totally gets stuck, and it is not clear where or why. A full IIS reset is needed.

"I am going to try to load test our site on our staging server to see if we can get it to fail outside of the production server. I suspect the issue can be replicated if you add a large load to a web app that is making extensive use of couchbase for caching. In our case we have to Couchbase clients that we use; one is to the memcached buckets we use purely for caching, and the second is to a couchbase bucket that currently only stores session data. Not sure that makes any difference, but we do use two clients per request. And since we use it for session data that one gets a good load on it but the cache one is hit many times per request.

And after some further investigation:

"However the good news is that it behaved differently to how it has in the past. Usually as soon as we turn it on and recycle the application pool, the site falls over and becomes non-responsive immediately, and the CPU gets pegged at 100% in the IIS process. In this case however we actually got a page load to come up pretty quickly after we turned it on, which for a second made me think it was working. But alas more page loads after that started to load up and the site ground to a halt. Oddly the CPU was not pegged at 100% like it normally does, but it was definitely way higher than normal, in the 80-95% range I think (normal CPU sits around 10-15% max once the site has come up and settled in).