Instant Messaging High Availability Overview

Configuring Instant Messaging for high availability (HA) by using the Sun Cluster agent provides for monitoring of and recovery from software and hardware failures. The high availability feature is implemented as a failover data service, not a scalable service, and is currently supported only on Solaris.

You can have multiple Instant Messaging nodes in an HA environment using the same SMTP server.

Before implementing an Instant Messaging HA environment using the Sun Cluster agent, decide which of the following HA deployments best meets your needs.

• Mixed HA Environment. This deployment consists of a local configuration and binaries, and global runtime files. The advantage to this setup is that upgrading Instant Messaging requires minimal downtime because you can upgrade on nodes where Instant Messaging is offline. The disadvantage is that you need to ensure that the same configuration and version of Instant Messaging exists on all nodes in the cluster. In addition, if you choose this option, you need to determine whether you will be using HAStoragePlus or the cluster file system for global runtime files.

• Global HA Environment. This deployment consists of a global configuration, binaries, and runtime files. This setup is easier to administer, but you need to bring Instant Messaging down on all nodes in the cluster before upgrading.