Saga Orchestration Pattern Using Event Sourcing and CQRS

Start Postgres and Axon Server

docker compose up -d

Saga Lifecycle

Happy path: CreateOrderCommand -> CommandCreatedEvent -> ProcessPaymentCommand -> PaymentProcessedEvent -> CreateShipmentCommand -> ShipmentCreatedEvent -> UpdateOrderStatusCommand(ORDER_COMPLETED) -> OrderStatusUpdatedEvent

Compensations:

1. Payment Failed: PaymentFailedEvent -> UpdateOrderStatusCommand(ORDER_FAILED) -> OrderStatusUpdatedEvent
2. Shipment Failed: ShipmentCreatedEvent(SHIPMENT_FAILED) -> CancelPaymentCommand -> PaymentCancelledEvent -> UpdateOrderStatusCommand(ORDER_FAILED) -> OrderStatusUpdatedEvent

Api Docs

Using Api Gateway: http://localhost:5555/docs

Test cases

First Create a User Balance with balance 5000 for example:

Copy the returned user id for order creation

Happy test

Create order with an amount less than user balance: 200 for example.

Create new order

Payment Failure

Create an order with amount greater than user balance.

Shipment Failure

Failure is hard coded in Shipment Service (Service fails for any order with amount less than 20).