What is inter-service communication and why is it important?
In layman's terms, inter-service communication means sharing information between two applications (services) over a network in a distributed system. Sometimes, we call this process messaging. In Chapter 2, Why Is Messaging Important in the Microservice Architecture?, we discussed different messaging technologies and had a brief overview of how those technologies can be used in a microservice architecture. In this section, we will explore this topic in detail. The following diagram depicts the two types of message flows within a microservice architecture:
North-South traffic
The requests that come from applications and services outside the microservice platform toward the microservice platform via a service gateway such as an API gateway are considered North-South traffic.