5.1 Planning the Internet Agent in a Linux Cluster

A major system configuration difference between the GWIA in a clustering environment and the GWIA in a regular environment is that you need to create a separate domain to house the GWIA in the clustering environment.

The Internet Agent Clustering Worksheet lists the information you need as you set up the GWIA in a clustering environment. You should print the worksheet and fill it out as you complete the tasks listed below:

5.1.1 Planning a Domain for the GWIA

The considerations involved in planning a domain for the GWIA are much the same as planning any other domain. In preparation, review Planning a New Domain, then print and fill out the New Domain Summary Sheet in Domains in the GroupWise 2012 Administration Guide.

Keep in mind the following cluster-specific details:

  • When you specify the location for the domain directory on the Domain Worksheet, remember that it is on a GroupWise partition, not on the node where you running the GroupWise Installation program. This location is referred to as the GWIA partition because it is where the GWIA message queues are located.

  • Do not concern yourself with the GroupWise agent information on the Domain Worksheet. You can stop with item 10. You will plan the MTA installation later.

When you have completed the Domain Worksheet, transfer the key information from the Domain Worksheet to the Internet Agent Clustering Worksheet.

INTERNET AGENT CLUSTERING WORKSHEET

Under Item 1: GroupWise Partition for the GWIA, transfer the domain location to the Internet Agent Clustering Worksheet.

Under Item 2: GWIA Domain Name, transfer the domain name and database directory to the Internet Agent Clustering Worksheet.

IMPORTANT:Do not create the new domain until you are instructed to do so in Section 5.2.1, Creating a Domain for the GWIA.

5.1.2 Selecting the GWIA Partition and Secondary IP Address

As with the MTA, the POA, and the DVA, the GWIA needs a secondary IP address that remains the same no matter which node in the cluster it is running on. You can place the GWIA and its domain on a GroupWise partition where a domain or post office already reside, which means that the GWIA shares the same secondary IP address as that domain or post office and fails over along with that domain or post office. Or you can place the GWIA and its domain on its own GroupWise partition, which means that it has its own secondary IP address and fails over independently.

INTERNET AGENT CLUSTERING WORKSHEET

Under Item 1: GroupWise Partition for GWIA, specify the secondary IP address for the GWIA partition.

Under Item 5: MTA Network Information, copy the same secondary IP address.

Under Item 6: GWIA Network Information, copy the same secondary IP address.

IMPORTANT:You must configure the GWIA to bind exclusively to the secondary IP address. Novell Cluster Services uses Postfix to send cluster email alerts using the primary IP address. Postfix and the GWIA both default to port 25. A conflict results unless you configure the GWIA so that it does not use the primary IP address. Instructions are provided in Forcing Use of the GWIA Secondary IP Address.

5.1.3 Determining an Appropriate Failover List for the Linux GWIA

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.

As with the MTA, the POA, and the DVA, you need to decide which nodes in the cluster are appropriate locations for the GWIA partition to fail over to. You must install the GWIA software on all of the nodes where you want the GWIA to be able to fail over. For a review of failover lists, see Section 2.6.2, Determining Appropriate Failover Lists for the Linux Agents, which describes the issues in the context of planning installations for the other GroupWise agents.

INTERNET AGENT CLUSTERING WORKSHEET

Under Item 3: GWIA Failover List, list the nodes that you want in the GWIA partition failover list.

5.1.4 Determining Cluster Resource Information for the Linux GWIA

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 Configure GroupWise for Clustering option, the GroupWise Installation program needs to know the mount point for the GroupWise partition where the GWIA domain is located.

INTERNET AGENT CLUSTERING WORKSHEET

Under Item 4: Cluster Resource Mount Point, list the mount point for the GroupWise partition where the GWIA domain is located.

5.1.5 Preparing DNS for the Clustered Linux GWIA

In order for the GWIA partition to be recognized on your network, DNS must have an MX record that includes the hostname corresponding to the secondary IP address of the GWIA partition. A DNS A record associates the secondary IP address with the hostname.

5.1.6 Preparing Your Firewall for the Clustered Linux GWIA

The GWIA receives incoming messages on the secondary IP address of the GWIA partition. Your firewall configuration must be modified to allow inbound TCP/IP traffic from the Internet to the GWIA secondary IP address on the following standard ports:

Protocol

Standard Port

IMAP4

143

LDAP

389

POP3

110

SMTP

25

By default, the GWIA sends outgoing messages on the primary IP address of the server where it is running. If you decide to use this default configuration, your firewall must be configured to allow outbound TCP/IP traffic from all nodes in the GWIA partition failover list. However, because Postfix uses the primary IP address for sending cluster email alerts, the default GWIA configuration is not recommended. To avoid a port conflict, configure the GWIA to bind to the secondary IP address, as described in Forcing Use of the GWIA Secondary IP Address.

If the GWIA has a large number of nodes on its failover list, you can configure the GWIA to send outgoing messages to a relay host, which then sends them out through the firewall using its own IP address rather than the address of the particular node where the GWIA was running. This reduces the amount of modification to your firewall required to set up the GWIA. However, if the relay host goes down, outgoing messages are delayed.

In preparation for installing the GWIA, configure your firewall as needed to handle the GWIA’s use of primary and secondary IP addresses when sending and receiving messages.

5.1.7 Planning the Linux MTA Installation

Follow the instructions in Section 2.6.4, Planning the Linux Agent Installation, then return to this point. After you follow the instructions, you will have a filled-out Agent Clustering Worksheet to use when you install the MTA.

IMPORTANT:Do not install the Linux MTA until you are instructed to do so in Section 5.2, Setting Up the GWIA in a Linux Cluster.

5.1.8 Planning the Linux GWIA Installation

Aside from the cluster-specific issues discussed in the preceding sections, the considerations involved in planning to install the GWIA are the same in a clustering environment as for any other environment. Review the installation instructions in Linux: Installing the GWIA in Installing the GroupWise Internet Agent in the GroupWise 2012 Installation Guide. Use the GroupWise Internet Agent Installation Worksheet to record the planning information you will need as you install the GWIA in your cluster.

IMPORTANT:Do not install the GWIA software until you are instructed to do so in Setting Up the GWIA in a Linux Cluster.