Our website is using Sun one web server 6.1 as our web server now. One Load balancer sends http requests to two web servers with sun one web server 6.1. We will upgrade these two web servers to Sun Java System Web server 7 this year. We may upgrade the web servers one by one. It is possible that we may upgrade one and let it runs on production in first week. And the second one will be upgrade in the second week. The upgraded web server will have 2048 bit SSL certificate and old one with 1024 SSL key. Therefore, our website may be servered by two web servers which have different web server versions and different SSL keys. We can upgrade these two server at the same time too. But I just want make sure that the first one works totally fine in the production environment, then implement the second one.
My question is: Can Sun Java System Web Server 7 & Sun one web server 6.1 with different SSL keys be used in one website at the same time?