What is message-oriented middleware?

A message oriented middleware is basically an asynchronous way to have applications communicate with each other by exchanging messages. The middleware is agnostic to the content of the messages. The advantage is the the processes of the application will not need to wait for a return or answer if the other side is down.

This works very well with the store and forward pattern. However if you have a request reply pattern where you are dependent on receiving an answer before going forward, you will require the same uptime from your middleware.

Exchange patterns are: point to point: store and forward, request reply,and pub/sub

Hope it helps