#aws #serverless #aws-api-gateway #api-gateway #stateful #stateless #full-duplex

Api Gateway High Level

It’s AWS service to proxy request to AWS downstream services like EC2, Lambda.

Integrations

  • Lambda
  • HTTP: Internal HTTP endpoints on-premise, ALB,…
  • AWS Service: Step Functions, SQS

Endpoint types

  • Edge-Optimized (default): best for latency in every locations (routing optimization), API Gateway is still placed at a region.
  • Regional: For client in one region, can combine with CF
  • Private: Must be in the VPC, exposed as VPCe

Security

  • User Authentication: Cognito, IAM, Custom Authorizers
  • Custom Domain Name HTTPS

Stateful and Stateless

  • Stateful communication requires server to keep session data like Cookie.
  • API Gateway Restful API is stateless
  • API Gateway WebSocket API is stateful full-duplex client server communication

Full Duplex, Half Duplex, Simplex

  • Simplex is the communication that is one way receiver. Like the keyboard.
  • Full Duplex is two way sending and receiving data tranmission simultaneously.
  • Half Duplex is two way sending and receiving but it takes turn for waiting another side to complete, waiting for some signal from other side before can continue.