7.1. Open source messaging servers

When building an application that requires asynchronous messaging, open source messaging servers are a compelling option. In this section, we’ll take a look at two such options. The first, ActiveMQ (available from http://activemq.apache.org) is a Java-based messaging middleware developed by the Apache Software Foundation. It’s a popular mid-size solution attractive not only for its price tag (free!) but also for packing the right combination of features and performance while requiring minimal setup and administration. The second, reliable-msg, is a pure-Ruby implementation suitable for small-scale deployments.

You can connect to ActiveMQ in a variety of ways, including REST and XMPP, both of which we covered in previous chapters, or through the JMS API, an option that’s available when deploying on JRuby (see appendix B). In this chapter, we’re going to use Stomp, the Streaming Text Orientated Messaging Protocol. It’s an open protocol that supports a variety of messaging brokers and programming languages, and, in combination with StompConnect, any messaging broker that supports the Java Message Service (JMS) API.