How do I set up a cluster?

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Overview

After installing the product, you have to create queue managers. Any queue manager you create is capable of working in a cluster.

Having decided that you want to create a cluster of queue managers, you need to consider which queue managers in the cluster are to hold the full repositories of cluster information. You can choose any number of queue managers for this purpose but the recommended number is two.

The smallest possible cluster contains only two queue managers. In this case both queue managers contain full repositories. You need only a small number of definitions to set this up, and yet there is a high degree of autonomy at each queue manager.

 

Establishing communication in a cluster

To establish communication between queue managers in a cluster, configure a link using one of the supported communication protocols. As part of this configuration, you also need channel initiators and channel listeners.

 

Channel initiator

All cluster queue managers need a channel initiator to monitor the system-defined initiation queue SYSTEM.CHANNEL.INITQ. This is the initiation queue for all transmission queues including the cluster transmission queue.

When you start a queue manager, a channel initiator is automatically started.

 

Channel listener

Run a channel listener program on each queue manager. A channel listener program 'listens' for incoming network requests and starts the appropriate receiver channel when it is needed.

To start use either the channel listener program provided by WebSphere MQ, or the facilities provided by the operating system (for example, inetd for TCP communications). To start the WebSphere MQ channel listener run:

runmqlsr -t tcp -p 1414 -m PARIS

Alternatively, use the MQSC command START LISTENER.

To use inetd to start channels, configure two files:

1. Edit the file /etc/services. (To do this be logged in as a superuser or root.) If you do not have the following line in that file, add it as shown:

   MQSeries 1414/tcp # Websphere MQ channel listener

   where 1414 is the port number required by WebSphere MQ. You can change this, but it must match the port number specified at the sending end.

2. Edit the file /etc/inetd.conf. If you do not have the following line in that file, add it as shown:

The updates become active after inetd has reread the configuration files. Issue the following commands from the root user ID:

1. Find the process ID of the inetd with the command:

   ps -ef | grep inetd

2. Run the command:

   kill -1 inetd processid

 

WebSphere is a trademark of the IBM Corporation in the United States, other countries, or both.

 

IBM is a trademark of the IBM Corporation in the United States, other countries, or both.