Subscription points

Subscriptions points are a feature provided by WebSphere Business Integration Message Broker that can be used to make information associated with a particular topic available in a number of different formats.

For example, stock prices might be published with a default currency of dollars, but might be required by subscribers expressed in other currencies.

This can be achieved by defining additional paths through the message flow that take each publication and convert the dollar stock price into another currency (for example, euros), before it is passed to its Publication node.

Each additional currency must be associated with a different subscription point and therefore a Publication node. The original publication in dollars is associated with the default subscription point.

Subscribers can then subscribe to stock prices using a combination of topic and the subscription point that provides the data in the correct currency.

Subscription points are not supported by MQSeries Publish/Subscribe. You must therefore be careful if you use them in a heterogeneous network. In particular, be aware that publications can only pass between WebSphere Business Integration Message Broker and MQSeries Publish/Subscribe brokers on the default subscription point.

All topics that are published in a MQSeries Publish/Subscribe broker domain are on the default subscription point. These topics are only available to MQRFH2 subscribers that subscribe to the topics without specifying a subscription point (that is, are using the default subscription point).

Similarly, clients at MQSeries Publish/Subscribe brokers can only subscribe to topics that are published on the default subscription point at WebSphere Business Integration Message Broker brokers (at Publication nodes that do not have a subscription point set).