22.1 Planning Your Messenger System in a Linux Cluster

Because the Messenger agents are not associated with GroupWise domains or post offices, the Messenger agents are easier to implement in a cluster than are the GroupWise agents. Section 22.5, Messenger Clustering Worksheet lists the information you need as you set up the Messenger agents in a clustering environment. You should print the worksheet and fill it out as you complete the tasks listed below:

22.1.1 Understanding Your Cluster

As described in Section 13.1, Installing Novell Cluster Services on Linux, you set up your cluster with a certain number of shared partitions and cluster resources.

MESSENGER CLUSTERING WORKSHEET

Under Items 1-5, record information about your cluster. This information corresponds to items 1-5 on the Section 13.7.1, System Clustering Worksheet.

22.1.2 Selecting the Messenger Partition and Secondary IP Address

If you are not planning to enable archiving, or if you are not anticipating a large Messenger archive, you can use one Messenger partition for both the Messaging Agent and the Archive Agent. If you anticipate archiving a large number of messages so that the Messenger archive grows very large, you might want to have a separate Messenger partition for the Archive Agent and its archive database. The steps in this section focus on setting up the Messenger agents on a single Messenger partition.

MESSENGER CLUSTERING WORKSHEET

Under Item 6: Shared Partition for Messenger, record the name and secondary IP address of the Messenger partition in your cluster.

If you want a separate Messenger partition for archiving, under Item 7: Shared Partition for Archiving, record the name and secondary IP address of the archiving partition in your cluster.

22.1.3 Determining an Appropriate Failover List for the Messenger Agents

By default, a Messenger partition is configured to have all nodes in the cluster in its failover list, organized in ascending alphanumeric order. Only one node at a time can have the Messenger partition mounted and active and the Messenger agents running. If a Messenger partition’s preferred node fails, the partition fails over to the next node in the failover list. The Messenger agents might need to run on any node that the Messenger partition fails over to.

MESSENGER CLUSTERING WORKSHEET

Under Item 8: Failover List for Messenger Agents, list the nodes that you want to have in the Messenger agents’ failover list.

22.1.4 Determining Cluster Resource Information for the Messenger Agents

A cluster resource is a shared partition, secondary IP address, application, service, Web server, etc., that can function successfully anywhere in the cluster. Cluster resources include the GroupWise agents and the Messenger agents. When you are installing the Messenger agents in a cluster, the Messenger Installation program needs to know the mount point for the Messenger partition where it can store agent startup files, log files, SSL certificate files, and the uid.conf file that enables the Messenger agents to run as a non-root user. By storing these files on a shared partition, the Messenger agents can access the files regardless of which node in the cluster the agents are currently running on.

MESSENGER AGENT CLUSTERING WORKSHEET

Under Item 9: Mount Point for Shared Storage, list the mount point directory for the Messenger partition where the Messenger startup and other files will be located.

22.1.5 Planning the Messenger Agent Installation

Aside from the cluster-specific issues discussed in the preceding sections, the considerations involved in planning to install the Messenger agents are the same in a clustering environment as for any other environment. Review Planning Your Novell Messenger System, then print and fill out the Novell Messenger Worksheet in Installing a Novell Messenger System in the Messenger 2.0 Installation Guide. Messenger must be installed on each node in the failover list (Messenger Clustering Worksheet item 8)

Continue with Setting Up Your Messenger System in a Linux Cluster.