Design Patterns and Best Practices in Java

Fan-out and quickest-reply pattern

In some applications, speed is very important, especially where real-time data is being handled, for example, on a betting site, where it is important to calculate the odds based on a live event. A goal scored in the last five minutes of time, for a match that was otherwise even, will dramatically change the odds in favor of a team, and you want this to be reflected on the website in a fraction of a second, before people start adding bets.

In such a case, where the speed of request handling is important, we would like multiple instances of the service to process the request. We will accept the response from the service that responded first, and discard other service requests. As you can see, this approach ...