Components

A microservices architecture composes one application from a suite of small services, each running in its own process and communicating with lightweight mechanisms. Services are built around business capabilities and are independently deployable by fully automated deployment machinery.

1. Individual Service Components — single responsibility: each microservice implements a specific business capability. Independent deployment: each service can be deployed, upgraded, and scaled independently.
2. Service Database — each microservice can have its own database, so services are loosely coupled and can evolve independently.
3. API Gateway — entry point for clients. Request dispatching, composition, and protocol translation; can streamline a set of microservices into a single API. Manages request rate limiting, security, caching, etc.
4. Service Discovery — find and communicate with each other without hardcoding service addresses. Often uses a service registry where services register their locations.
5. Load Balancer — distributes incoming requests to service instances so no single instance is overwhelmed.
6. Communication Protocols — HTTP/REST, RPC, or messaging.
7. Centralized Configuration Management — configuration of service environments separate from the service code and binaries.
8. Circuit Breaker — detect failures and encapsulate the logic of preventing a failure from constantly recurring. Helps prevent system failures and maintain resilience.
9. Logging and Monitoring — diagnose and monitor health and performance. Centralized logging can provide an aggregated view of logs across services.
10. Containerization and Orchestration — package into containers (e.g. Docker) which include everything needed to run them. Orchestration tools like Kubernetes manage and scale these containers.
11. Authentication and Authorization — only legitimate requests are processed. Can be centralized or managed by individual services.
12. Event-Driven Architecture — services produce or consume events. Helps decouple services and ensure asynchronous communication.
13. API Composition — for requests that span multiple services, intermediate layer(s) compose the result from various services.
14. Versioning — evolve the microservices over time without affecting the consumers.
15. Backup and Replication — data safety and availability in case of failures.
16. Decentralized Data Management — each microservice has its own view on data models, which may be different from other services.

These components collectively aim at a scalable, maintainable, and resilient architecture. Microservices also introduce complexity; consider the trade-offs against the project's requirements.

ChatGPT 4 — 23/10/2023.