Beyond the hype, it’s necessary to understand what a service mesh is and what concrete problems it solves so you can decide whether you might need one.
A brief introduction to the service mesh
The service mesh is a dedicated infrastructure layer for handling service-to-service communication in order to make it visible, manageable, and controlled. The exact details of its architecture vary between implementations, but generally speaking, every service mesh is implemented as a series (or a “mesh”) of interconnected network proxies designed to better manage service traffic.
This type of solution has gained recent popularity with the rise of microservice-based architectures, which introduce a new breed of communication traffic. Unfortunately, it’s often introduced without much forethought by its adopters. This is sometimes referred to as the difference between the north-south versus east-west traffic pattern. Put simply, north-south traffic is server-to-client traffic, whereas east-west is server-to-server traffic. The naming convention is related to diagrams that “map” network traffic, which typically draw vertical lines for server-client traffic, and horizontal lines for server-to-server traffic. In the world of server-to-server traffic, aside from considerations happening at the network and transport layers (L3/L4), there’s a critical difference happening in the session layer to account for.
Read more at O’Reilly
