NestJSNestJS Microservices là pattern giao tiếp giữa services dùng message-passing thay vì HTTP. NestFactory.createMicroservice() tạo microservice với transport layer được chọn.
Transport layers: TCP cho internal services latency thấp, Redis cho Pub/Sub và simple messaging, NATS cho lightweight cloud-native messaging, Kafka cho high-throughput event streaming, RabbitMQ cho complex routing với dead-letter queues, gRPC cho strongly-typed high-performance calls.
Hai pattern messaging: @MessagePattern('event') cho Request/Response (sender chờ reply), @EventPattern('event') cho Fire-and-forget (không chờ reply). API Gateway dùng ClientsModule.register() inject ClientProxy, gọi client.send('pattern', data) cho request/response trả về Observable, client.emit('pattern', data) cho fire-and-forget. Hybrid app có thể serve cả HTTP và Microservices cùng lúc với app.connectMicroservice().
NestJS Microservices use message-passing instead of HTTP for inter-service communication. NestFactory.createMicroservice() creates a microservice with the chosen transport layer.
Transport layers: TCP for low-latency internal services, Redis for Pub/Sub and simple messaging, NATS for lightweight cloud-native messaging, Kafka for high-throughput event streaming, RabbitMQ for complex routing with dead-letter queues, gRPC for strongly-typed high-performance calls.
Two messaging patterns: @MessagePattern('event') for Request/Response (sender waits for reply), @EventPattern('event') for Fire-and-forget (no reply expected). API Gateways use ClientsModule.register() to inject a ClientProxy, calling client.send('pattern', data) for request/response (returns Observable) or client.emit('pattern', data) for fire-and-forget. Hybrid apps can serve both HTTP and Microservices simultaneously with app.connectMicroservice().