Novell GROUPWISE 7 - INTEROPERABILITY GUIDE, Руководство пользователя

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138 GroupWise 7 Interoperability Guide
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13.6 Deciding How to Install and Configure the
Linux Agents in a Cluster
There are several cluster-specific issues to consider as you plan to install the Linux MTA and POA
in your clustered GroupWise system:
Š
Section 13.6.1, “Recording Secondary IP Addresses for the Agents,” on page 138
Š Section 13.6.2, “Determining Appropriate Failover Lists for the Agents,” on page 138
Š
Section 13.6.3, “Determining Cluster Resource Information for the Linux Agents,” on
page 139
Š
Section 13.6.4, “Planning the Linux Agent Installation,” on page 139
13.6.1 Recording Secondary IP Addresses for the Agents
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
Configure GroupWise for Clustering option, the GroupWise Installation program sets the --ip
switch in each agent startup file to its unique secondary IP address.
If you are going 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 7 Administration Guide .
13.6.2 Determining Appropriate Failover Lists for the Agents
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.
AGENT CLUSTERING WORKSHEET
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.