Messaging Server requires Directory Server, but not necessarily a local copy. You will need the Sun Cluster Core component as well as the Sun Cluster Agents for Directory Server and Messaging Server. If a remote Directory Server is used, then the Sun Cluster Agent for Directory Server is not required.
Installing, configuring, and starting the product components in the correct order is crucial for a successful Sun Cluster implementation.
Installing the Java ES Sun Cluster product component
Configuring the Sun Cluster framework
Installing and configuring Messaging Server using instructions in the Sun Java Communications Suite 5 Installation Guide
Installing additional Java ES product components that are required
Configuring the Sun Cluster data services using the agents for the relevant Java ES product components
At least three installation sessions are performed on each node in the cluster, one using the Communications Services installer and two using the Java ES installer. For instructions on using the Communications Services installer, refer to Sun Java Communications Suite 5 Installation Guide.