Publish/subscribe: changes to proxy subscription propagation using PROXYSUB(FORCE)
In this release, when you configure a topic object with the parameter PROXYSUB set to FORCE, IBM® MQ automatically disables individual proxy subscriptions for topic strings below this point in the topic tree.
- A wildcarded subscription is created that matches this topic object's topic string and all topic strings below this point in the topic tree.
- This wildcarded subscription is propagated to all neighboring queue managers in a publish/subscribe topology.
In previous releases, setting PROXYSUB to FORCE did not automatically prevent individual proxy subscriptions being generated and propagated for topic strings below this point in the topic tree. In the current release, setting PROXYSUB to FORCE automatically disables individual proxy subscriptions for topic strings below this point in the topic tree.
In previous releases, to reduce the number of proxy subscriptions, you set the pscProxySubFlags tuning parameter to 1. This setting explicitly disabled all proxy subscriptions, except the wildcarded PROXYSUB(FORCE)
subscription. In the current release, you no longer need to set the pscProxySubFlags parameter.
- On distributed systems and IBM i, AMQ5824 or AMQ5968
- On z/OS®, CSQT824I or CSQT968I
To rectify the problem, either modify the topic hierarchy to remove the nested clusters or streams, or change both objects to have the same PROXYSUB setting.
For performance considerations when using PROXYSUB(FORCE)
, see Subscription performance in publish/subscribe networks.