What is a service mesh and when is it useful?

A service mesh is a dedicated infrastructure layer for making service-to-service communication safe, fast, and reliable. If you’re building a cloud native application, you need a service mesh. It can help connect, secure, control, and observe services. At a high level, a service mesh helps reduce the complexity of these deployments and ease the strain on your development teams.

How does Linkerd provide observability by collecting metrics and telemetry about services? How does Linkerd use mTLS to create secure lines of communication between services? How does Linkerd improve reliability by using retries, timeouts, load baling, and traffic shifting?