Hi, we have two IIS 6.0 application servers behind a load balancer which adds cookies to responses to make sure that sessions always go to the same app server. Our testers access this from behind a Squid proxy.
Here's the problem: Ever now and then, a request in a session which resides on app server A is sent by the load balancer to app server B. This happens in spite of the load balancer cookie (and the ASP.NET session cookie, for what it's worth) being the same as before. We have seen the behavior with both a Cisco and a F5 load balancer. The interesting part is that everything works fine if we do not use the Squid proxy. If users go through the proxy, we are able to reproduce the problem within 5 to 10 minutes of testing. Hence the question: Can anybody imagine a scenario which could cause this? Any help is greatly appreciated. Thanks, Robert