Messaging tends to concentrate on the reliable exchange of messages around a network; using queues as a reliable load balancer and topics to implement publish and subscribe. An ESB typically tends to add different features above and beyond messaging such as orchestration, routing, transformation and mediation. I’d recommend reading about the Enterprise Integration Patterns which … Read more
I’d suggest To ESB or not to ESB to start with, written by the creator of Mule.
Although ESB is based on messaging, it is not “just” messaging and not just a buzzword. So if you start with plain old async messaging, the early networks tended to be very point-to-point. You had to wire up (i.e. configure through some admin interface) each connection and each pair of destinations and if you dared … Read more
An API Gateway is a proxy provided for the client. The Gateway gives the client a consistent interface regardless of any changes within the internal system. It allows the internal system to change without affecting the client. The API Gateway can also provide consistent cross-cutting concerns such as security logging, reporting and API analytics. An … Read more
Mule is an ESB (Enterprise Service Bus). RabbitMQ is a message broker. An ESB provides added layers atop of a message broker such as routing, transformations and business process management. It is a mediator between applications, integrating Web Services, REST endpoints, database connections, email and ftp servers – you name it. It is a high-level … Read more
Queue browsing is not supported directly, but if you declare a queue with NO auto acknowledgements and do not ACK the messages that you receive, then you can see everything in it. After you have had a look, send a CANCEL on the channel, or disconnect and reconnect to cause all the messages to be … Read more
I generally find it is best to have exchanges grouped by object type / exchange type combinations. in you example of user events, you could do a number of different things depending on what your system needs. in one scenario, it might make sense to have an exchange per event as you’ve listed. you could … Read more
It is now 2016 and a lot has changed since the question was initially asked, so I’d like to revisit it for new viewers. Strategically speaking Apache Camel has stayed true to its roots and has not evolved into a heavyweight nor fully-fledged runtime platform. It is versatile and modular, and can run: Embedded in … Read more
It’s a fairly high level concept of abstraction. The central concept is that the ESB provides the middleware and interfaces that allow businesses to connect their applications without writing code. This could include mediation to reconcile incompatible protocols, data, and interaction. The idea of a central bus on which everything passes gives opportunity for additional … Read more
If I had to summarize, here’s what I’d say: If you need commercial support, go for NServiceBus. If you’re comfortable with using forums as a means of support, MassTransit is a great option. The developers have been very responsive to our issues so far. If you choose MassTransit, now you will choose between MSMQ and … Read more