3 Microservices

the API gateway vs ESB

API gateway can also perform cross-cutting infrastructure-related functions, such as security, metrics gathering, request-ID generation, and so on.

Notice that unlike the enterprise service bus (ESB) in service-oriented architecture, the API gateway in microservices does not contain any business logic, nor does it perform any orchestration or mediation.

Deployed as containerized services (such as Docker)
or as serverless functions.

GCP => Cloud Function (Serverless)
K8S for containerized services

Why Mircoservices?

Service discovery

Service Registry [DNS]

  1. Self
  1. Orchestration Engine

Sidecar (Envoy)

Kubernetes (K8S)

  1. Proxy
  1. Self

Service Mesh (Istio)

Istio

Service mesh with Sidecar proxy

Control and Data Plane

Prometheus

Pilot, Citadel, Galley

Microservice => Business Logic
Sidecar Proxy => Comm, Security, Retry, Metrics, Tracing

Good for high scalability, Agility, and Fault tolerance