JMS and ESB - how they are related?

Question

For me JMS and ESB seem to be very related things and I\'m trying to understand how exactly they are related.

I\'ve seen a sentence that JMS can be used as a transpo

Answer 1

This Transformation does not happen automatically. You need to configure the mapping or write transformation service

Look at https://access.redhat.com/knowledge/docs/en-US/JBoss_Enterprise_SOA_Platform/4.2/html/SOA_ESB_Message_Transformation_Guide/ch02s03.html

Regards, Raja Nagendra Kumar, C.T.O www.tejasoft.com

Answer 2

• An addition to the above list is the latest Open Source ESB - UltraESB

JMS is not well suited for the integration of REST services, File systems, S/FTP, Email, Hessian, SOAP etc. which are better handled with an ESB that supports these types natively. For example, if you have a process that dumps a CSV file of 500MB at midnight, and you want another system to pickup the file, parse CSV and import into a database, this can easily be accomplished by an ESB - whereas a solution with just JMS will be bad. Similarly, integration of REST services, with load balancing/failover to multiple backend instances can be done better with an ESB supporting HTTP/S natively.

Answer 3

ESB offers integration with a lot of different protocols in addition to JMS.
Most use JMS behind the scenes to transfer, stor and move messages. One such solution OpenESB, uses XML format messages.

There are open source ESB which you could checkout -

• OpenESB
• Apache Camel
• MuleESB
• WSO2 ESB

JMS implementation like ActiveMQ come with Camel inbuilt into them.

Answer 4

I would say ESB is like a facade into a number of protocals....JMS being one of them.

Answer 5

JMS offers a set of APIs for messaging: put a message on a queue, someone else, sometime later, perhaps geographically far away takes the message off the queue and processes it. We have decoupled in time and location of the message provider and consumer. Even if the message consumer happens to be down for a time we can keep producing messages.

JMS also offers a publish/subscribe capability where the producer puts the message to a "topic" and any interested parties can subscribe to that topic, receiving messages as and when they are produced, but for the moment focus just on the queue capabilty.

We have decoupled some aspects of the relationship between provider and consumer. However some coupling remains. First, as things stand every message is processed in the same way. Suppose we want to introduce different kinds of processing for different kinds of messages:

 if ( message.customer.type == Platinum )
      do something special

Obviously we can write code like that, but an alternative would be to have a messaging system that can send different messages to different places we set up three queues:

 Request Queue, the producer(s) puts their requests here
 Platinum Queue, platinum consumer processing reads from here
 Standard Queue, a standard consumer reads messages from here

And then all we need is a little bit of cleverness in the queue system itself to transfer then messsage from the Request Queue to the Platinum Queue or Standard Queue.

So this is a Content-Based Routing capability, and is something that an ESB provides. Note that the ESB uses the fundamental Queueing capabilities offered by JMS.

A second kind of couppling is that the consumer and producer must agree about the message format. In simple cases that's fine. But when you start to have many producers all putting message to the same queue you start to hit versioning problems. New message formats are introduced but you don't want to change all the existing providers.

  Request Version 1 Queue  Existing providers write here
  Request Version 2 Queue  New provider write here, New Consumer Reads here

And the ESB picks up the Version 1 Queue messages and transforms them into Version 2 messages and puts them onto the Version 2 queue.

Message transformation is another possible ESB capability.

Have a look at ESB products, see what they can do. As I work for IBM, I'm most familiar with WebSphere ESB

Answer 6

There are JMS message brokers , that you can easily configure with ESB. https://docs.wso2.com/display/ESB470/JMS+Transport