Develop Payment Application with Microservices Architecture

Architecture

High-Level Design

Low-Level Design (ERD)

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Functional Requirement

• payment-service
  1. able to perform charge payment
  2. able to perform refund
  3. able to get latest payment status
• wallet-service
  1. able to top-up the wallet balance
  2. able to credit user wallet balance
  3. able to debit user wallet balance
  4. able to get list of user wallet transaction
• payment-provider-gateway-service
  1. able to simulate payment flow to respective external payment provider
• order-service
  1. CRUD order items
  2. checkout order (payment)
  3. cancel order (refund)
• user-service
  1. CRUD
• API gateway-service
  1. able to route the request accordingly
• registry-service
  1. able to monitor all services

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Non-functional Requirement

• should be able to handle ACID from data POV
• should be able to perform retry in case payment is failed
• should be able to handle high volume of transactions with low latency
• should be able to handle scalability aspect
  • auto-scaling
  • load-balancing
• should be able to handle availability aspect
  • reduce single point of service (correlate with scalability)
  • add monitoring capability
    • use logging
    • use metrics (Prometheus)
    • use tracing (Jaeger)
    • health checks (API Gateway will collect all the health check status and export to Prometheus)

Tech stack

Name	Descriptions
Spring boot + Java 11	Framework and programming language
MySQL	Database
Kong	API Gateway
Consul	Service Discovery
RabbitMQ	Messaging Platform
Jaeger	Tracing capability
Prometheus	Monitoring

Service communication

We’re going to implement mixed communication type, which sync and async.

1. Sync communication will be done through HTTP only for : payment-service → payment-gateway-service
2. Async communication will be done through messaging (RabbitMQ) and using Pub/Sub pattern.