ActiveMQ is a common framework used in enterprise software solutions to implement JMS messaging via TCP, SSL, HTTP(s), VM, and STOMP, which is one of the many ways to allow inter-bundle communications. ActiveMQ provides a lot of benefits, from handling data bursts to providing failover and scaling. In this chapter, we will cover the why and how of implementing the embedded ActiveMQ broker in a Karaf environment. We will also look at how to administer the broker under different deployment topologies.

Before we begin, we should discuss when to use the embedded broker deployment strategy versus standalone. This is just as important as learning how, since an embedded broker can bring the system to its knees just as fast as bad architecture. In many cases, the initial thought is embedding ActiveMQ is easier to deploy and will make messaging faster. While there is some truth to this, in most cases, the benefit does not outweigh the cost. Allowing ActiveMQ to share the JVM resources...