> I have a Camel Route that drains all of the queues and topics (excluding Advisory Topics) from the old broker to the new broker.
Conceptually speaking, there is no real way to "drain a topic" since topics don't hold messages like a queue does. When dealing with topics, messages are stored in _subscriptions_ which are created by consumers. Furthermore, any message sent to a topic without any subscriptions is simply dropped. So, depending on your use-case you may need to recreate any relevant subscriptions on the destination broker and have Camel drain the corresponding subscriptions on the source broker. > Is there a way to just create the queue or topic on the new broker with Camel without creating this stub message? Destinations are created when a message is sent or when a consumer attaches. If Camel doesn't send a message then the destination won't be created. I'm not 100% sure about your advisory question, but I believe you are correct. Ultimately your best bet is to test various configuration permutations for your use-case and see which one works best. Justin On Thu, Oct 3, 2024 at 9:51 AM William Crowell <wcrow...@perforce.com.invalid> wrote: > Good morning, > > I am using ActiveMQ Classic 5.18.5 on 2 separate brokers on Windows > (unfortunately). One broker is using the default kahaDB, and the other > broker has been configured with database persistence using Microsoft SQL > Server. I am migrating messages from the old broker using kahaDB to the > new broker setup with database persistence. > > I have a Camel Route that drains all of the queues and topics (excluding > Advisory Topics) from the old broker to the new broker. I am using XPath > on the to get all the queues and topics using these 2 URLs on the old > ActiveMQ broker: > > http://xxx:8161/admin/xml/queues.jsp > http://xxx:8161/admin/xml/topics.jsp > > What I have noticed is that queues that have no pending messages in them > are not created on the new broker. I always have to put a small stub > message in the queue in order for it to be migrated over to the new broker. > > A few questions on this: > > 1) Am I approaching this wrong? Is there a way to just create the queue > or topic on the new broker with Camel without creating this stub message? > > 2) I do not want to migrate the Advisory topics over to the new broker > because those will get created anyway when the topics and queues are moved > over. Is this assumption correct? > > Thank you in advance, > > William Crowell > > > This e-mail may contain information that is privileged or confidential. If > you are not the intended recipient, please delete the e-mail and any > attachments and notify us immediately. > >
