The Problem with Point to Point Communication
Point-to-point communication between servers usually works just fine when one or two instances are communicating. One or two instances communicating However, if you increase the number of applications, the total number of connections increases. Three instances communicating In fact, the total number of connections increases as a square of the number of application instances. So, if you are running 100 instances, you will be maintaining O(100^2) connections. The scaling becomes quite painful....