Armeria is a battle-tested microservice framework created by Trustin Lee, the original author of Netty, and maintained by engineers at LINE Corporation. It uniquely supports serving gRPC, Thrift, REST, and GraphQL endpoints on a single server instance sharing the same port, with or without TLS. This multi-protocol capability eliminates the need for separate server processes or reverse proxies when a service needs to expose different API styles to different consumers.
Cross-cutting concerns that typically require custom middleware in other frameworks are handled through Armeria's decorator system. Metrics collection, distributed tracing via Zipkin or Brave, client-side load balancing, authentication, rate limiting, circuit breaking, and automatic retries are all available as composable decorators that can be layered onto any service or client. The framework also auto-generates interactive API documentation with sample payloads, enabling ad-hoc testing of gRPC and Thrift endpoints directly from a browser.
Armeria integrates cleanly with Spring Boot and Dropwizard, allowing teams to adopt it incrementally by serving gRPC traffic through Armeria while leaving REST endpoints to the existing framework. Built on top of Netty's event-driven architecture, it delivers high throughput and low latency even under heavy concurrent load. The framework supports Kotlin coroutines and Reactive Streams for modern asynchronous programming patterns, making it a strong choice for teams building polyglot microservice architectures at scale.
