Distributed publish/subscribe troubleshooting

Distributed publish/subscribe troubleshooting

Use the advice given in the subtopics to help you to detect and deal with problems when we use publish/subscribe clusters or hierarchies.

Before you begin
If your problems relate to clustering in general, rather than to publish/subscribe messaging using clusters, seeQueue manager clusters troubleshooting.
There are also some helpful troubleshooting tips in Design considerations for retained publications in publish/subscribe clusters.

Routing for publish/subscribe clusters: Notes on behavior
Use the advice given here to help you to detect and deal with routing problems when you are using clustered publish/subscribe messaging.
Checking proxy subscription locations
A proxy subscription enables a publication to flow to a subscriber on a remote queue manager. If your subscribers are not getting messages that are published elsewhere in the queue manager network, check that your proxy subscriptions are where you expect them to be.
Resynchronization of proxy subscriptions
Under normal circumstances, queue managers automatically ensure that the proxy subscriptions in the system correctly reflect the subscriptions on each queue manager in the network. Should the need arise, we can manually resynchronize a queue manager's local subscriptions with the proxy subscriptions that it propagated across the network using the REFRESH QMGR TYPE(PROXYSUB) command. However, you should do so only in exceptional circumstances.
Loop detection in a distributed publish/subscribe network
In a distributed publish/subscribe network, it is important that publications and proxy subscriptions cannot loop, because this would result in a flooded network with connected subscribers receiving multiple copies of the same original publication.
Parent topic: IBM MQ Troubleshooting and support

Related information

Configure a publish/subscribe cluster
Designing publish/subscribe clusters
Distributed publish/subscribe system queue errors