go-watermill

tags:

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  • online
  • reviewed
  • microservices
  • go
  • frameworks

watermill

Contents

__Roadmap info from [ roadmap website ] (https://roadmap.sh/golang/go-microservices/watermill) __

Watermill

Watermill is an event streaming library for handling asynchronous requests in go. It provides multiple sets of implementations for pub/sub. e.g: You can use conventional pub/sub implementations like Kafka or RabbitMQ, but also HTTP or MySQL binlog, if that fits your use case.

Visit the following resources to learn more:

Watermill__

  • Purpose: Event-driven systems, pub/sub architecture.
  • Key Features: Messaging abstraction, integrates with Kafka, RabbitMQ, Google Cloud Pub/Sub.
  • Best For: Microservices communicating via asynchronous events and messages.

Example: 

pub, err := message.NewPublisher(
rabbitmq.NewPublisherConfig("amqp://guest:guest@localhost:5672/"),
nil,
)

Watermill__ - Event-Driven Systems

Solution Example: E-Commerce Order Processing

  • Use Case: In an e-commerce platform, multiple services such as order management, inventory, and payment can communicate asynchronously using events.
  • Framework Usage: Each service (e.g., OrderService, PaymentService, InventoryService) publishes or subscribes to messages via Watermill using message brokers like Kafka or RabbitMQ.
  • Workflow:
  1. OrderService publishes a message to the order_created topic after a customer places an order.
  2. PaymentService subscribes to the order_created topic and processes payments.
  3. InventoryService updates stock based on the order_processed event.

Example: 

msg := message.NewMessage(watermill.NewUUID(), []byte(`{"order_id":123}`))
err := publisher.Publish("order_created", msg)