Real world use of JMS/message queues? [closed]

Answer 1

Apache Camel used in conjunction with ActiveMQ is great way to do Enterprise Integration Patterns

Answer 2

We are using JMS for communication with systems in a huge number of remote sites over unreliable networks. The loose coupling in combination with reliable messaging produces a stable system landscape: Each message will be sent as soon it is technically possible, bigger problems in network will not have influence on the whole system landscape...

Answer 3

Use them all the time to process long-running operations asynchronously. A web user won't want to wait for more than 5 seconds for a request to process. If you have one that runs longer than that, one design is to submit the request to a queue and immediately send back a URL that the user can check to see when the job is finished.

Publish/subscribe is another good technique for decoupling senders from many receivers. It's a flexible architecture, because subscribers can come and go as needed.

Answer 4

I've used it to send intraday trades between different fund management systems. If you want to learn more about what a great technology messaging is, I can thoroughly recommend the book "Enterprise Integration Patterns". There are some JMS examples for things like request/reply and publish/subscribe.

Messaging is an excellent tool for integration.

Answer 5

We have used messaging to generate online Quotes

Answer 6

JMS (ActiveMQ is a JMS broker implementation) can be used as a mechanism to allow asynchronous request processing. You may wish to do this because the request take a long time to complete or because several parties may be interested in the actual request. Another reason for using it is to allow multiple clients (potentially written in different languages) to access information via JMS. ActiveMQ is a good example here because you can use the STOMP protocol to allow access from a C#/Java/Ruby client.

A real world example is that of a web application that is used to place an order for a particular customer. As part of placing that order (and storing it in a database) you may wish to carry a number of additional tasks:

• Store the order in some sort of third party back-end system (such as SAP)
• Send an email to the customer to inform them their order has been placed

To do this your application code would publish a message onto a JMS queue which includes an order id. One part of your application listening to the queue may respond to the event by taking the orderId, looking the order up in the database and then place that order with another third party system. Another part of your application may be responsible for taking the orderId and sending a confirmation email to the customer.