Saga Pattern Microservices

Simple order flow to demo some concepts: ⚡ = 💗💎❤️

• Microservices using Spring Boot, Spring Cloud, Spring Cloud Stream
• Database per service using Postgresql
• Saga Pattern (Saga Orchestration): Distributed transaction span multiple services.
• Outbox Pattern: Avoid dual-writes, no 2PC required using Kafka,Kafka Connect, Debezium , Outbox Event Router

Choreography in SAGA Pattern

Orchestration-based saga

Prerequisites

• Java 17
• Docker
• Docker-run
• Docker-compose

Structure 'Order-Service' Demo

├── pom.xml
├── src
│   ├── main
│   │   ├── java
│   │   │   └── com
│   │   │       └── hoangtien2k3
│   │   │           └── orderservice
│   │   │               ├── OrderServiceApplication.java
│   │   │               ├── api
│   │   │               │   └── OrderController.java
│   │   │               ├── domain
│   │   │               │   ├── OrderRequest.java
│   │   │               │   ├── OrderUseCase.java
│   │   │               │   ├── PlacedOrderEvent.java
│   │   │               │   ├── entity
│   │   │               │   │   ├── Order.java
│   │   │               │   │   └── OrderStatus.java
│   │   │               │   └── port
│   │   │               │       ├── EventHandlerPort.java
│   │   │               │       ├── OrderRepositoryPort.java
│   │   │               │       └── OrderUseCasePort.java
│   │   │               └── infrastructure
│   │   │                   ├── config
│   │   │                   │   └── JacksonMapperConfig.java
│   │   │                   ├── message
│   │   │                   │   ├── EventHandlerAdapter.java
│   │   │                   │   ├── log
│   │   │                   │   │   ├── MessageLog.java
│   │   │                   │   │   └── MessageLogRepository.java
│   │   │                   │   └── outbox
│   │   │                   │       ├── OutBox.java
│   │   │                   │       └── OutBoxRepository.java
│   │   │                   └── repository
│   │   │                       ├── OrderEntity.java
│   │   │                       ├── OrderJpaRepository.java
│   │   │                       └── OrderRepositoryAdapter.java
│   │   └── resources
│   │       └── application.yml

Get Started

Setup environment

## docker run
docker run --name postgres -p 5434:5432 -e POSTGRES_PASSWORD=12042003 -d postgres:16

## docker compose
docker-compose up -d

Build projects

./mvnw clean package -DskipTests=true

Start Services

Run services api-gateway, order-service, customer-service, inventory-service

./mvnw -f api-gateway/pom.xml spring-boot:run

./mvnw -f order-service/pom.xml spring-boot:run

./mvnw -f customer-service/pom.xml spring-boot:run

./mvnw -f inventory-service/pom.xml spring-boot:run

Service's name	Endpoint
Api Gateway	localhost:8080
Order service	localhost:9090
Customer service	localhost:9091
Inventory service	localhost:9093

Start outbox connectors

Create outbox connectors

sh register-connectors.sh

Clean Up

Delete all connectors

sh delete-connectors.sh

Useful commands

Create new customer

curl --location 'localhost:8080/customer-service/customers' \
--header 'Content-Type: application/json' \
--data '{
    "username": "usertest",
    "fullName": "Test user 1",
    "balance": 100
}'

Create new product

curl --location 'localhost:8080/inventory-service/products' \
--header 'Content-Type: application/json' \
--data '{
    "name": "Test product 1",
    "stocks": 10
}'

Create new order

curl --location 'localhost:8080/order-service/orders' \
--header 'Content-Type: application/json' \
--data '{
    "customerId": "f0a000ad-ea44-4fa1-853b-207f9d9abe2c",
    "productId": "d212c9d6-da3b-4fe2-b016-a852c8a8d32f",
    "quantity": 1,
    "price": 2
}'

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

This project is licensed under the MIT License

MIT License
Copyright (c) 2024 Hoàng Anh Tiến

Contributors ✨

Hoàng Anh Tiến 💻 🚧 🤔 🎨 🐛