You can either convert an existing topic into a cluster
topic, or create a new cluster topic. You do this by navigating to
the topic properties, then specifying the name of the cluster that
is to host this topic, and the cluster routing mechanism to use for
publications on this topic.
Before you begin
Create a cluster containing two or more queue managers, as described in Creating a queue manager cluster.The SYSTEM.BASE.TOPIC
and
SYSTEM.DEFAULT.TOPIC
should not typically be used as cluster topics. This is
because SYSTEM.BASE.TOPIC
is present on all cluster queue managers, therefore it
only affects the local queue manager unless it is modified on all queue managers to have a correctly
functioning publish/subscribe cluster. The entire topic tree is also within a single cluster,
preventing subsections of topic space being in a cluster, and making it harder to divide subsections
of topic space into separate clusters. However, there are situations where it is necessary, such as
IBM Integration BusCollective migration.
For more information, see Publish/subscribe messaging in IBM Knowledge Center.
There are also a number of reasons not to
make SYSTEM.DEFAULT.TOPIC
a cluster topic: it is present on all queue managers in a
cluster, so it only affects the local queue manager, and all topics defined while it is a cluster
topic also become cluster topics in the same cluster.
About this task
To create a new cluster topic in the IBM MQ Explorer
Navigator view, complete the following steps:
Procedure
- Expand the cluster queue manager in which you want to create
a new cluster topic.
- In the navigation pane, select Topics.
A list of existing topics is displayed in the main
pane.
- Either select an existing topic, or create a new topic.
- To select an existing topic, double-click the topic in the main
pane.
- To create a new topic, right-click Topics in
the navigation pane, then select . For more information,
see Creating a new topic.
- In the properties pane, click Cluster to
open the Cluster properties page.
- Type the name of the cluster you want the topic to belong
to in the Cluster topic field.
- Optional:
For IBM MQ 8.0 and later versions, select the routing
mechanism from the Cluster route drop-down list.
The choices are as follows:
- Direct
- Messages published on one queue manager are sent directly from that queue manager to every
subscription on any other queue manager in the cluster.
- Topic host
- Messages published on one queue manager are sent from there to a queue manager that hosts the
definition of the topic. That topic host queue manager routes the message on to every
subscription on any other queue manager in the cluster.
- Click Apply to save the change.
Results
The topic has now become a cluster topic.