TIBCO EMS servers provide fault tolerant mechanism which allows you to configure two servers - one being the primary server and the other as backup or standby server. The primary server accepts client connections or requests and interacts with clients to send or receive messages. If the primary server fails, the backup server takes over, it becomes the new active server and resumes the operation. It does not support more than two servers in this configuration.
TIBCO EMS provides you options to configure shared state and unshared state failover. To avoid message loss, duplication or out of order message delivery, it is always preferred to use shared state failover.
Although TIBCO EMS does not support load balancing in a cluster, TIBCO EMS does support multiple installations where agent and integration servers point to different TIBCO servers. In this scenario, the load is distributed across the queues.