There are several cluster-specific issues to consider as you plan to install the Linux MTA, POA, and DVA in your clustered GroupWise system:
By default, the GroupWise agents listen on all IP addresses, both primary and secondary, that are bound to the server. This means that any time there is a possibility of two of the same type of agent loading on the same node, it is important that each agent use the appropriate secondary IP address of the GroupWise partition. The secondary IP address moves with each agent when it fails over, so that, in the case of the POA, GroupWise clients do not lose their connections to the POA. When you use the option, the GroupWise Installation program sets the --ip switch in each agent startup file to its unique secondary IP address.
If you are planning to set up a GroupWise name server to help GroupWise clients locate their post offices, make sure that the default POA port number of 1677 is used somewhere in the cluster. For more information, see Simplifying Client/Server Access with a GroupWise Name Server
in Post Office Agent
in the GroupWise 2012 Administration Guide.
If you want to install the DVA along with the POA, it can participate in the cluster by failing over along with the POA and its post office. However, clustering is not necessary in order to provide high availability for the DVA. As an alternative to clustering, you can install the DVA on multiple servers outside the cluster, as described in Scaling Your DVA Installation
in Document Viewer Agent
in the GroupWise 2012 Administration Guide.
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AGENT CLUSTERING WORKSHEET |
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Under Item 3: MTA Network Information, transfer the domain secondary IP address from the System Clustering Worksheet to the Agent Clustering Worksheet. Under Item 6: POA Network Information, transfer the post office secondary IP address from the System Clustering Worksheet to the Agent Clustering Worksheet. Under Item 7: DVA Network Information, transfer the post office secondary IP address from the System Clustering Worksheet to the Agent Clustering Worksheet. |
By default, a GroupWise 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 a particular GroupWise partition mounted and active. If a GroupWise partition’s preferred node fails, the partition fails over to the next node in the failover list. You should customize the failover list for each GroupWise partition based on the fan-out-failover principle.
When a node fails, its partitions should not all fail over together to the same secondary node. Instead, the partitions should be distributed across multiple nodes in the cluster. This prevents any one node from shouldering the entire processing load typically carried by another node. In addition, some partitions should never have the potential of being mounted on the same node during a failover situation. For example, a post office and POA that service a large number of very active GroupWise client users should never fail over to a node where another very large post office and heavily loaded POA reside. If they did, users on both post offices would notice a decrease in responsiveness of the GroupWise client.
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AGENT CLUSTERING WORKSHEET |
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Under Item 2: Domain Failover List, list the nodes that you want to have in the domain partition failover list. The MTA might need to run on any node that the domain partition fails over to. Therefore, you will install the agent software on all of the nodes in the domain failover list. If you are planning the post office on a different GroupWise partition from where the domain is located, under Item 5: Post Office Failover List, list the nodes that you want to have in the post office partition failover list. The POA (and the DVA if you installed along with the POA) might need to run on any node that the post office partition fails over to. Therefore, you will install the agent software on all of the nodes in the post office failover list. |
A cluster resource is a shared partition, secondary IP address, application, service, Web server, and so on, that can function successfully anywhere in the cluster. Cluster resources include the GroupWise agents and the Messenger agents. When you use the option, the GroupWise Installation program needs to know the mount point for the GroupWise partition where it will create the domain and post office. For example, you might create a /mnt/gwsystem mount point, or you might create /mnt/dom1 and /mnt/po1 mount points. The Installation program also needs to know the secondary IP address of the GroupWise partition. In the Installation program, you provide these pieces of information in the and fields.
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AGENT CLUSTERING WORKSHEET |
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Under Item 8: Cluster Resource Information, list the mount point and secondary IP address for the GroupWise partition where the domain and post office will be located. |
Aside from the cluster-specific issues discussed in the preceding sections, the considerations involved in planning to install the GroupWise Linux agents are the same in a clustering environment as for any other environment. Review Planning the GroupWise Agents
, then print and fill out the GroupWise Agent Installation Worksheet
in Installing GroupWise Agents
in the GroupWise 2012 Installation Guide for each location where you will install the Linux MTA, POA, and/or DVA.
IMPORTANT:Do not install the Linux agent software until you are instructed to do so in Section 3.0, Setting Up a Domain and a Post Office in a Linux Cluster.