we send ajax request through jsp to '/getList' to the list. DisplayListDetailsAction has a instance variable is_list_valid, which is initialized to false. and then set to true after some validations. Now this works very well in single web-server and single application server environment. But if tried same thing in multiple web-server and multiple application server environment. This is_list_valid flag is not initialized to false every time for every ajax request. Why this is so?