You can configure Messaging Server, Calendar Server, and Instant Messaging to be highly available by using clustering software. Messaging Server supports both Sun Cluster and Veritas Cluster Server software. Calendar Server and Instant Messaging support Sun Cluster software. When using clustering software, a secondary Messaging Server, Calendar Server, or Instant Messaging host provides services to users if the primary system is taken offline for maintenance or is down due to a problem.
Even without the use of Sun Cluster, Messaging Server has built-in monitoring capabilities that continuously check the status of server processes and service availability. Messaging Server can restart processes and services automatically, if necessary. Messaging Server logs failures and recovery operations, which you can use for reporting and analysis.
Instant Messaging may make use of server pools to provide redundancy. In a server pool, two or more Instant Messaging servers provide the instant messaging services for a single domain. If a server fails, another server in the pool handles the additional load.
Additionally, you can deploy the Communications Suite products in a highly available configuration through use of redundant components. This kind of deployment gives services a high level of uptime. A highly available deployment of this sort requires the redundancy of every component in the service architecture. These components include a duplicate data store server, duplicate network interface cards, and duplicate system storage.
This guide does not discuss the details of using Sun Cluster in highly available deployments for Communications Suite. See the Sun Cluster, Messaging Server, Calendar Server, and Instant Messaging documentation for more information on this topic.