Novell Documentation: GroupWise 6.5 - Deciding How to Install and Configure the Agents in a Cluster

Deciding How to Install and Configure the Agents in a Cluster

There are several cluster-specific issues to consider as you plan to install the Windows MTA and POA in your clustered GroupWise system:

Planning Cluster-Unique Port Numbers for Agents in the Cluster

By default, the GroupWise agents listen on all IP addresses, both primary and secondary, that are bound to the server on their specified port numbers. The primary IP address is the IP address of the physical node. Secondary IP addresses are the IP addresses associated with GroupWise resource groups.

Any time there is a possibility of two of the same type of agent running on the same node, it is important that each agent use a cluster-unique port number, even though each agent is using the unique IP address established for each GroupWise resource group. The best way for you to avoid port conflicts is to plan your cluster so that each agent in the cluster runs on a cluster-unique port. Print out a copy of the Network Address Worksheet to help you plan cluster-unique port numbers for all GroupWise agents in your GroupWise system.

The following filled-out version of the Network Address Worksheet illustrates one way this can be done:

Domain Information

Domain	MTA IP Address	MTA MTP Port	MTA HTTP Port
Provo1	123.45.67.81	7100	7180

Post Office Information

Post Office	POA IP Address	POA C/S Port	POA MTP Port	POA HTTP Port
Development	(same as MTA)	1677	7101	7181
Manufacturing	123.45.67.82	1678	7102	7182

Internet Agent Information

Internet Agent	GWIA IP Address	MTA MTP Port	MTA Live Remote Port	MTA HTTP Port	GWIA HTTP Port
GWIA Domain MTA	123.45.67.83	7110	7677	7183	N/A
Internet Agent (GWIA)	(same as MTA)	N/A	N/A	N/A	9850

WebAccess Information

WebAccess Agent	WebAccess IP Address	MTA MTP Port	MTA HTTP Port	WebAccess Agent Port	WebAccess HTTP Port
WebAccess Domain MTA	123.45.67.84	7120	7184	N/A	N/A
WebAccess Agent (GWINTER)	(same as MTA)	N/A	N/A	7205	7205 (same as agent)

This example places the Development post office in the same resource group with the Provo1 domain; therefore, the Provo1 MTA and the Development POA use the same IP address. The Manufacturing post office is placed in a different resource group; so the Manufacturing post office has a different IP address. The Internet Agent and the WebAccess Agent each have their own domains and separate resource groups.

The example also illustrates that the MTA, the POA, and the Internet Agent use different port numbers for agent ports and HTTP ports. In contrast, the WebAccess Agent uses the same port number for the agent port and the HTTP port.

The example uses default port numbers where possible. For example, the default MTA message transfer port is 7100 and the default POA client/server port is 1677. Incrementing port numbers are used in the example when multiple components have the same type of ports. For example, port numbers 1677 and 1678 are both POA client/server ports and port numbers 7180 through 7184 are all HTTP ports. Incrementing from the default port numbers generates unique, though related, port numbers.

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 and specify the IP address of the post office resource group, not the IP address of a specific node. For more information, see "Simplifying Client/Server Access with a GroupWise Name Server" in "Post Office Agent" in the GroupWise 6.5 Administration Guide.

NETWORK ADDRESS WORKSHEET
Fill out the Network Address Worksheet to help you determine resource group IP addresses and cluster-unique port numbers for all GroupWise agents in the cluster. (MTA, POA, Internet Agent, WebAccess Agent). Refer to the IP addresses you planned for the domain and post office resource groups under items 4 and 5 on the System Clustering Worksheet.

After you have filled out the Network Address Worksheet, transfer the IP addresses and the cluster-unique port numbers from the Network Address Worksheet to the Agent Clustering Worksheet so that they will be available in the sequence in which you will need them as you set up the GroupWise agents in the cluster.

AGENT CLUSTERING WORKSHEET
Under Item 4: MTA Network Information, transfer the resource group IP address and cluster-unique port numbers for the MTA from the Network Address Worksheet to the Agent Clustering Worksheet. Under Item 7: POA Network Information, transfer the resource group IP address and cluster-unique port numbers for the POA from the Network Address Worksheet to the Agent Clustering Worksheet.

AGENT CLUSTERING WORKSHEET

Under Item 4: MTA Network Information, transfer the resource group IP address and cluster-unique port numbers for the MTA from the Network Address Worksheet to the Agent Clustering Worksheet.

Under Item 7: POA Network Information, transfer the resource group IP address and cluster-unique port numbers for the POA from the Network Address Worksheet to the Agent Clustering Worksheet.

Deciding Where to Install the Agent Software

In a Microsoft cluster, the agents must run as Windows services. When you install the Windows MTA and POA, you can choose between two different installation locations:

Location	Description
Each node in the cluster	The c:\grpwise directory is the default location provided by the Agent Installation program.
Shared disk	If you create a drive:\grpwise directory on the same shared disk with the domain or post office directory, the agent software and startup files fail over and back with the domains and post offices that the agents service.

Because the agents must be installed as Windows services in a Microsoft cluster, you must initially run the Agent Installation program for each node in the cluster so that the Windows services for the agents get created, regardless of where you are planning to run the agents from. However, for updates, you need to run the Agent Installation program only once if you are running the agents from a shared disk.

The following sections can help you choose which installation location would be best for your clustered GroupWise system:

Advantages of Installing to a Shared Disk

Using a drive:\grpwise directory for each GroupWise shared disk has several advantages:

When you update the agent software, you only need to update it in one place for a particular domain or post office, not on every node in the resource group's possible owners list. This prevents the potential problem of having a domain or post office fail over to a node where a different version of the agent software is installed.
Having the agent startup files on the same node as the domain or post office makes them easy to find.
If you change information in the agent startup files, you only need to change it in one place, not on every node in the resource group's possible owners list.

If you want to back up the GroupWise data, you can back up the domain and/or post office directories and the agent software from the same shared disk.

Disadvantages of Installing to a Shared Disk

Installing the agents on the same shared disk with a domain or post office does have some disadvantages:

You must install the agent software each time you create a new domain or post office on a new shared disk.
GroupWise administrators who are used to the GroupWise agents being installed in c:\grpwise might be confused by not finding them there in the clustered GroupWise system.
You must remember where you installed the GroupWise agents when you update the agent software. Accidently installing a GroupWise Support Pack to the default location of c:\grpwise on the active node would not have the desired results if the original agent software was installed to a shared disk.

Recommendation

Whichever method you choose, be consistent throughout the entire cluster. Either put all the GroupWise agents on the shared disks with the domains and post offices they service, or put them all in c:\grpwise directories on all nodes. If you put them on shared disks with domains and post offices, make sure there are no agent files in c:\grpwise directories on nodes to confuse the issue at a later time.

Even if you choose to install the agents to the c:\grpwise directory of multiple nodes, you can still store the agent startup files on shared disks with the domains and post offices. The significant advantage of this approach is that you only have one startup file to modify per agent.

AGENT CLUSTERING WORKSHEET
Under Item 1: Agent Installation Location, mark whether you will install the agent software to the shared disk with a domain or post office, or to each node in the cluster. If necessary, specify where the agent startup files will be stored. Under Item 2: Domain Name, transfer the domain name, shared disk, and directory from the System Clustering Worksheet to the Agent Clustering Worksheet. Under Item 5: Post Office Name, transfer the post office name, shared disk, and directory from the System Clustering Worksheet to the Agent Clustering Worksheet.

AGENT CLUSTERING WORKSHEET

Under Item 1: Agent Installation Location, mark whether you will install the agent software to the shared disk with a domain or post office, or to each node in the cluster. If necessary, specify where the agent startup files will be stored.

Under Item 2: Domain Name, transfer the domain name, shared disk, and directory from the System Clustering Worksheet to the Agent Clustering Worksheet.

Under Item 5: Post Office Name, transfer the post office name, shared disk, and directory from the System Clustering Worksheet to the Agent Clustering Worksheet.

Planning the Agent Services

In a Microsoft cluster, the MTA and POA must be set up as service resources. A service resource for a GroupWise agent must include the following information:

Name: The name by which the agent service will be listed in the resource group (for example, MTA Service or POA Service)
Possible Owners: The list of nodes in the cluster to which the GroupWise agent can fail over (the same as the possible owners of the resource group to which the agent service belongs)
Resource Dependencies: Other resources in the resource group that must be online before the GroupWise agent can start on a new node (for example, the Group IP Address resource and the Physical Disk resource where the domain or post office directory is located)

AGENT CLUSTERING WORKSHEET
Under Item 3: MTA Service Resource, specify the MTA service resource name and list any possible resource dependencies. Under Item 6: POA Service Resource, specify the POA service resource name and list any possible resource dependencies.

AGENT CLUSTERING WORKSHEET

Under Item 3: MTA Service Resource, specify the MTA service resource name and list any possible resource dependencies.

Under Item 6: POA Service Resource, specify the POA service resource name and list any possible resource dependencies.

Planning the Windows Agent Installation

Aside from the cluster-specific issues discussed in the preceding sections, the considerations involved in planning to install the GroupWise Windows agents are the same in a Microsoft cluster as in 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 6.5 Installation Guide for each location where you will install the Windows MTA and/or POA.

Fill out the Windows Agent Worksheet, taking into account the following cluster-specific issues:

GROUPWISE AGENT INSTALLATION WORKSHEET
Under Item 2: Agents and Locations, mark POA Local to Post Office and MTA Local to Domain. In a Microsoft cluster, a domain or post office and its agent must be located on the same node in order to fail over together. Under Item 3: Installation Path, take into account your decision based on Deciding Where to Install the Agent Software . Under Item 8: Installation Options, mark Install as Windows Services. Under Item 6: Domains and Item 7: Post Offices, refer to the Domain and Post Office Worksheets you filled out during Planning a New Clustered Domain and Planning a New Clustered Post Office, and to the Network Address Worksheet you completed during Planning Cluster-Unique Port Numbers for Agents in the Cluster.

GROUPWISE AGENT INSTALLATION WORKSHEET

Under Item 2: Agents and Locations, mark POA Local to Post Office and MTA Local to Domain. In a Microsoft cluster, a domain or post office and its agent must be located on the same node in order to fail over together.

Under Item 3: Installation Path, take into account your decision based on Deciding Where to Install the Agent Software .

Under Item 8: Installation Options, mark Install as Windows Services.

Under Item 6: Domains and Item 7: Post Offices, refer to the Domain and Post Office Worksheets you filled out during Planning a New Clustered Domain and Planning a New Clustered Post Office, and to the Network Address Worksheet you completed during Planning Cluster-Unique Port Numbers for Agents in the Cluster.

IMPORTANT: Do not install the Windows agent software until you are instructed to do so in Setting Up a Domain and Post Office in a Microsoft Cluster.

Continue with Setting Up a Domain and Post Office in a Microsoft Cluster.