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 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:
As with the GroupWise agents, the Messenger agents need cluster nodes, native Heartbeat resources, Messenger resources, and a cluster resource group in order to function in your Heartbeat cluster. If you put the Messenger agents in the same cluster resource group, they fail over together. If you put them in separate cluster resource groups, then they fail over separately.
For a review of these cluster components, see Section 13.1, Installing Novell Cluster Services on Linux.
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MESSENGER CLUSTERING WORKSHEET |
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Under Item 1: Messenger Agent Nodes, list the nodes that you want to use for the Messenger agents. Identify each node by its DNS hostname and the IP address that it is physically configured with. Under Item 2: Messaging Agent Cluster Resource Group, specify the name of the cluster resource group to hold the native and Messenger resources associated with the Messaging Agent. Under Item 3: Archive Agent Cluster Resource Group, specify the name of the cluster resource group to hold the native and Messenger resources associated with the Archive Agent. Under Item 4: Native Heartbeat Resources, list the cluster resource names and parameters for the EVMS shared storage partition, the file system, and the secondary IP address that you want to use for the Messenger agents. Under Item 5: Messenger Resources, list the cluster resource names and parameters for the Messaging Agent and the Archive Agent. The identifiers for the Messenger agents are their full eDirectory™ object names. You can look them up in the /etc/opt/novell/groupwise/gwha.conf file, which is the configuration file for the GroupWise High Availability service. The required format is .messagingagent.server_nameserver.messengerservice.organization. |
If you are not anticipating a large Messenger archive, you can use one cluster resource group 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 cluster resource group for the Archive Agent and its archive database. The steps in this section focus on setting up the Messenger agents in a single cluster resource group.
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MESSENGER CLUSTERING WORKSHEET |
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Under Item 7: Messaging Agent Network Information, record the secondary IP address of the Messaging Agent cluster resource group. If you want a separate cluster resource group for archiving, under Item 8: Archiving Agent Network Information, record the secondary IP address of the Archiving Agent cluster resource group. |
By default, a Heartbeat cluster is configured to have all nodes in the cluster available for failover. Only one node at a time can have a particular cluster resource group mounted and active. If a cluster resource group’s initial node fails, the resource group fails over to another node in the cluster. As with the GroupWise agents, you need to select the nodes in the cluster where you want the Messenger agents to fail over. You must install the Messenger software on all of the nodes where you want the Messenger agents to be able to fail over.
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MESSENGER CLUSTERING WORKSHEET |
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Under Item 6: Messenger Agent Constraints, list the nodes where you want the Messenger agents to fail over. |
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 where you want the Messenger agents to be able to fail over (Messenger Clustering Worksheet item 6)
Continue with Setting Up Your Messenger System in a Linux Cluster.