Linkerd: Up and Running

Chapter 1. Service Mesh 101

Linkerd is the first service mesh—in fact, it’s the project that coined the term “service mesh.” It was created in 2015 by Buoyant, Inc., as we’ll discuss more in Chapter 2, and for all that time it’s been focused on making it easier to produce and operate truly excellent cloud native software.

But what, exactly, is a service mesh? We can start with the definition from the CNCF Glossary:

In a microservices world, apps are broken down into multiple smaller services that communicate over a network. Just like your wifi network, computer networks are intrinsically unreliable, hackable, and often slow. Service meshes address this new set of challenges by managing traffic (i.e., communication) between services and adding reliability, observability, and security features uniformly across all services.

The cloud native world is all about computing at a huge range of scales, from tiny clusters running on your laptop for development up through the kind of massive infrastructure that Google and Amazon wrangle. This works best when applications use the microservices architecture, but the microservices architecture is inherently more fragile than a monolithic architecture.

Fundamentally, service meshes are about hiding that fragility from the application developer—and, indeed, from the application itself. They do this by taking several features that are critical when creating robust applications and moving them from the application into the infrastructure. This ...