What is a multicast graph? Martin Fowler in his blog post on "The LMAX Architecture" tried to describe the component called Disruptor as a multicast graph of queues


  At a crude level you can think of a Disruptor as a multicast graph of
  queues where producers put objects on it that are sent all the
  consumers for parallel consumption through separate downstream
  queues...


I'm having difficulties understanding the nature of a multicast graph
Here is a technical paper on the LMAX Architecture (I just followed a link found on the blog you linked here): http://disruptor.googlecode.com/files/Disruptor-1.0.pdf

An example of a multicast graph is on page 9 of the PDF. There are also examples of multicast graphs (compared to various other options) here: http://en.wikipedia.org/wiki/Multicast