Planning Your Messenger System in a 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. The Messenger Clustering Worksheet lists all the information you will 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:


Understanding Your Cluster

Fill out items 1 through 5 on the Messenger Clustering Worksheet with information about your cluster. This information corresponds to items 1-5 on the System Clustering Worksheet. For background information, see Meeting Software Version Requirements and Installing Novell Cluster Services.


Planning Messenger Administration

If you have set up a cluster-enabled shared volume for GroupWise administration, as described in Deciding Whether to Cluster-Enable the Shared Volumes Used by GroupWise, you can use the same cluster-enabled shared volume for the Messenger administration files. For example, you might have a shared pub: volume with a \public directory where you install the Messenger snap-in to ConsoleOne®. Or you can install the Messenger snap-in on one or more administrator workstations.

MESSENGER CLUSTERING WORKSHEET

Under Item 6: Installation Location for Messenger Administration, mark where you want to install the Messenger snap-in to ConsoleOne.

If you plan to install the Messenger snap-in to ConsoleOne on a cluster-enabled shared volume, under Item 7: Shared Volume for Messenger Administration, list the IP address of the shared volume and the directory where you want to install the Messenger snap-in.

IMPORTANT:  Cluster-enabling relies on successful short name resolution throughout your system. Review Ensuring Successful Name Resolution for GroupWise Volumes, which describes the issues in the context of planning MTA and POA installations for GroupWise.


Deciding Where to Install the Messenger Agent Software

When you install the NetWare® Messenger agents in a clustering environment, you can choose between two different installation locations:

Location Description

Each node
in the cluster

The sys:\system directory is the default location provided by the Messenger Installation program.

Shared volume

If you create a vol:\system directory on a cluster-enabled shared volume, the agent software and startup files fail over and back along with supporting files such as the Messenger archive.

IMPORTANT:  Cluster-enabling relies on successful short name resolution throughout your system. Review Ensuring Successful Name Resolution for GroupWise Volumes, which describes the issues in the context of planning MTA and POA installations for GroupWise.

You must install to a cluster-enabled shared volume if you do not want a separate Messenger archive to be created on each node where the Archive Agent runs. If you do not want to use a shared volume, you should plan to install the Archive Agent separately outside the cluster.

MESSENGER CLUSTERING WORKSHEET

Under Item 8: Installation Location for Messenger Agents, mark where you want to install the Messenger agent software.

Continue with the planning instructions for the installation location you want to use:


Each Node in the Cluster

Make sure you have filled out item 5 on the Messenger Clustering Worksheet with a complete list of nodes in the cluster. Continue with Planning the Messenger Agent Installation.


Shared Volume

For convenience throughout the rest of this section, the term "Messenger volume" means "a cluster-enabled shared volume where the Messenger agents are installed." Complete the following planning tasks for the Massager volume:


Selecting the Messenger Volume

If you are not planning to enable archiving, or if you are not anticipating a large Messenger archive, you can use one Messenger volume. 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 volume for the Archive Agent and the archive database. The steps in this section cover setting up the Messenger agents on a single Messenger volume.

MESSENGER CLUSTERING WORKSHEET

Under Item 9: Shared Volume for Messenger Agents, record the name and IP address of the Messenger volume.


Determining an Appropriate Failover Path for the Messenger Volume

By default, a Messenger volume is configured to have all nodes in the cluster in its failover path, organized in ascending alphanumeric order. Only one node at a time can have the Messenger volume mounted and active. If a Messenger volume's preferred node fails, the volume fails over to the next node in the failover path.

MESSENGER CLUSTERING WORKSHEET

Under Item 10: Failover Path for Messenger Volume, list the nodes that you want to have in the Messenger volume failover path. The Messenger agents might need to run on any node that the Messenger volume fails over to.


Selecting IP Address Resolution Methods for the Messenger Volume

Because you are using a cluster-enabled volume for the Messenger agents, you must ensure that short name resolution is always successful. For background information, see Ensuring Successful Name Resolution for GroupWise Volumes.

MESSENGER CLUSTERING WORKSHEET

Under Item 11: IP Address Resolution Methods, mark the short name address resolution methods you want to implement to ensure that the UNC paths stored in ConsoleOne can be successfully resolved into the physical network address of the Messenger volume.


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 System Worksheet" in "Installing a Novell Messenger System" in the Messenger 1.0 Installation Guide. Transfer the following information from the Messenger Clustering Worksheet to the Messenger System Worksheet:

Continue with Setting Up Your Messenger System in a Cluster.