Error while performing Form Based Authentication on Windchill cluster environment

Hi All,

if anyone could help me out with this scenario it would be of great help.

Currently I am working in a clustered environment with apache load balancer. I have customized windchill logout functionality and I am getting logoff option and session is getting ended when I perform logoff action. I have two slaves and a master where when load balancer switches from slave 1 to slave 2 windchill throws error 'you are not authorized to view this file'. I then shut down slave 2 and worked only with slave 1 everything was working fine. 

I have configured on monolithic servers on both Windows as well as RHEL servers but first time I tried with cluster environment. 

Can anyone let me know what might be the possible error because of which I am getting this abnormal behaviour of Windchill? And also how should I proceed with the form based authentication on Windchill and is it good to configure form based authentication on a clustered environment?