CODEWITHSUNDEEP
activemq-classic
djna
djna

Reputation: 55897

ActiveMQ Classic Console Durable Subscriptions

I am using ActiveMQ Classic, and would like help understanding the Console as it relates to Topics and Durable subscriptions.

Using the console I create a durable subscriber for a topic, and send a message to that topic. I can see these items in the Subscribers tab

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But what does it mean? Why is my subscriber offline, how do I bring it to life?

Also, why do I have an Active non-durable subscriber? When I click it I see

No connection could be found for ID ID:Davids-MacBook-Pro.local-62384-1625654634846-3:1

Is that a problem?

I am working entirely in the Console. The Console offers a capability to create a subscriber, but so far as I can see this does not do anything. What is the purpose of the Console capability to create a Subscriber?

Upvotes: 0

Views: 487

Answers (1)

Justin Bertram
Justin Bertram

Reputation: 34988

The ActiveMQ Classic web console is mainly a tool to inspect what's happening on the broker. The other functionalities like creating a durable topic subscription and sending a message are useful mainly for extremely basic testing purposes. Creating subscriptions and sending messages are really the job of external messaging applications.

The reason the durable topic subscriber is "offline" is because it was created by the console and the console won't maintain an "online" durable subscriber. An "online" durable subscriber is one where the connection is active and the consumer is connected and ready to receive messages. When the console creates a durable subscriber it doesn't leave it connected. As far as I can tell the only useful thing about it is that you can send a message in the topic and see it land in the durable subscription.

The non-durable subscriber is created implicitly when you send a message with the console. This subscription is for advisory messages. When you click on the non-durable subscriber and see "No connection could be found" that's because the subscriber is defunct since the send operation is complete and the connection was closed. This looks like a bug as far as I can tell. The subscription will timeout and close after a bit. If you keep refreshing the page you'll see it disappear eventually.

Lastly, keep in mind that the ActiveMQ Classic web console is not particularly well-maintained and there have been a handful of attempts over the years in the community to remove it for this reason.

Upvotes: 1

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