Saga Orchestration (Spring Boot + Kafka, Java 19)

This is a demo multi-module Maven project implementing a Saga Orchestration pattern using Spring Boot and Apache Kafka.

Modules

• kafka-common — shared event classes & topic names
• orchestrator-service — exposes REST /api/orders to start a saga and coordinates via Kafka
• order-service — tracks order status (in-memory)
• inventory-service — simple in-memory stock, reserves/releases
• payment-service — mock payment
• shipping-service — mock shipping

Run

1. Start Kafka locally on localhost:9092 (e.g., Confluent Platform or Docker).
2. Build: mvn -q -DskipTests package
3. In separate terminals, run each service:
   • mvn -pl orchestrator-service spring-boot:run
   • mvn -pl order-service spring-boot:run
   • mvn -pl inventory-service spring-boot:run
   • mvn -pl payment-service spring-boot:run
   • mvn -pl shipping-service spring-boot:run

Create an order

curl -X POST "http://localhost:8080/api/orders?userId=u1&itemName=item&quantity=1&amount=100"

Check order statuses:

curl "http://localhost:8081/orders"

Check inventory snapshot:

curl "http://localhost:8082/inventory"