Topic mapping on an IBM MQ link
A topic mapping is an association that defines which messages published in WebSphere Application Server or the IBM MQ network, should be forwarded to the other publish/subscribe system.
We define one or more topic mappings for a broker profile. The broker profile defines the connection between WAS and an IBM MQ queue manager or separate publish/subscribe broker. The topic mapping links a specific topic in the WAS service integration bus with its equivalent in the IBM MQ network.
When defining a topic mapping, we choose if messages are to flow from IBM MQ to WAS, or from WAS to IBM MQ, or if the flow is two-way, or bidirectional. If a topic mapping is bidirectional, a message is safeguarded from being continually republished on alternating sides of the publish/subscribe bridge.
In your topic mapping, the topic name and its position in the hierarchy (or tree) of topics must be the same in WAS and in the IBM MQ network. Use wild cards, as described in Wild cards in topic mapping. For example, if we set up a topic mapping for "stock/IBM" with a direction from the WAS service integration bus to IBM MQ, the publish/subscribe bridge subscribes to the topic "stock/IBM" in WAS, and receives the messages published to the topic. The publish/subscribe bridge then publishes the messages to the topic "stock/IBM" in the IBM MQ network.
Messages published by a service integration JMS client are transferred to an IBM MQ network if an appropriate topic mapping has been created. This is presented to the IBM MQ network as only the topic name, for example, "sports/football". A suitably configured IBM MQ JMS application can use this information to publish further information to the same topic, but the original WAS JMS application receives these messages only if appropriate topic mapping has been configured.
If we delete an IBM MQ link, we must first unsubscribe and delete your topic mappings, to ensure there are no outstanding subscriptions in WAS or the IBM MQ network. For the process to unsubscribe, see Prepare to remove a foreign bus connection between a service integration bus and an IBM MQ network.
Subtopics
- Wild cards in topic mapping
Wild cards can be used in topic mapping on an IBM MQ link for publish/subscribe messaging, but there are differences between wild cards in WAS service integration, and wild cards in an IBM MQ network.
Add or modify topic mappings on the IBM MQ link publish/subscribe broker Prepare to remove a foreign bus connection between a service integration bus and an IBM MQ network