Environment: Two instances of Platform Server (say A & B) running behind a Load Balancer and Platform clients are connected to both instances through the Load Balancer.
In case of fail-over, one of the Platform server instance (say A) stops working due any reason. So, Platform clients that have sessions established with Platform Server instance A will face the problem and other Platform clients with sessions established with Platform Server instance B can continue working. Platform clients which are connected to the failed instance A need to re-login to the Platform Server to resume their work.
Note: Session replication is used in Active-Active fail-over. Quark Publishing Platform server doesn’t support Active-Active fail-over.