Creating a single topic space in a publish/subscribe cluster

Scale up a publish/subscribe system to run on multiple queue managers. Use a publish/subscribe cluster to provide each publisher and subscriber with a single identical topic space.

Before you begin

You have implemented a publish/subscribe system on a single version 7 queue manager.

Always create topic spaces with their own root topics, rather than relying on inheriting the attributes of SYSTEM.BASE.TOPIC. If you scale your publish/subscribe system up to a cluster, you can define your root topics as cluster topics, on the cluster topic host, and then all your topics are shared throughout the cluster.

About this task

You now want to scale the system up to support more publishers and subscribers and have every topic visible throughout the cluster.

Procedure

  1. Create a cluster to use with the publish/subscribe system.
    If you have an existing traditional cluster, for performance reasons it is better to set up a new cluster for the new publish subscribe system. You can use the same servers for the cluster repositories of both clusters
  2. Choose one queue manager, possibly one of the repositories, to be the cluster topic host.
  3. Ensure every topic that is to be visible throughout the publish/subscribe cluster resolves to an administrative topic object.
    Set the CLUSTER attribute naming the publish/subscribe cluster.

What to do next

Connect publisher and subscriber applications to any queue managers in the cluster.

Create administrative topic objects that have the CLUSTER attribute. The topics are also propagated throughout the cluster. Publisher and subscriber programs use the administrative topics so that their behavior is not altered by being connected to different queue managers in the cluster

If you need SYSTEM.BASE.TOPIC to act like a cluster topic on every queue manager, you need to modify it on every queue manager.