So you want to do publish-subscribe with ActiveMQ across distributed topics and be reliable. You can just use durable subscriptions, right? Well, you could, but if you’re using clustering with ActiveMQ, you may run into unintended behavior. I was recently at a client, and I noticed this behavior, and I also noticed the same behavior is present when using Weblogic JMS clustering as well. So what are the problems, and what does ActiveMQ bring to the table to solve them?