Understanding Pub-Sub communication
The Pub-Sub pattern has gained a fair amount of popularity and acclaim and is widely used in distributed systems. Pub is short for Publisher and Sub is short for Subscriber. Essentially, this pattern revolves around publishing data, contextually called messages, to an intermediary messaging system, which can be described as resilient and reliable, and then having subscribing applications monitor this intermediary system. Once a message is detected, the subscribing application will conduct its processing as necessary.
Understanding message queues
Before we explore the Pub-Sub method, we need to understand the basics of messaging systems and how they work. The first model we will look at is called a message queue. A message queue is usually implemented as a bridge between two systems, a publisher and a consumer. When a publisher places messages in the queue, a consumer processes the information in the message as soon as it becomes available....
