I have 2 web servers which are identicaly configured ( exactly the same hardware, same system, same updates, shared IIS configuration ) and are working in Network Load Balancing. Cluster is configured to multiple host with affinity single. When I turn on both host session of ASP.NET application breaks. When I stop host 1 ( which has priority 1 ) the whole traffic goes to host 2 properly but still session breaks ( users are logged out after 2-4 clicks ), when I turn off host 2 ( which has priority 2 in NLB ) and turn on host 1 ( which has priority 1 in NLB ) everything works fast and properly, sesion doesnt break. That is very strange to me becasue one host works properly when the other breaks even that hosts are identicall. Also there is the same application code taken from shared folder by both hosts.
I made one more try by configuring not clustered IP for the host on which application breaks ( host 2 ). When the IP is not clustered the application work properly on both hosts so it is not .NET nor system configuration.
Please advice what to do? Do u think reconfiguring NLB can help? How to debug what is wrong? Why session breaks only on one of the hosts even there is 1 host started in NLB at a time.
Thank you in advance for your help