Blockchain Development with Hyperledger

Loosely coupled design

Let's now return to that idea of loose-coupling. Event producers and event consumers do not directly know about each other—they are said to be loosely coupled. For example, when a participant is added to a business network, existing participants do not need to contact the new joiner to introduce themselves. Instead, the existing participants listen for a new participant event if they are interested. Likewise, if a participant joins a network, it doesn't need to reach out to everyone and everything it is interested in, it just listens for events it thinks are significant—events that might cause it to act. We can see that the event producers and event consumers don't explicitly know about each other—they only know about ...