alibaba/nacos

Nacos is a platform built by Alibaba for managing the infrastructure of distributed systems, specifically the three problems that arise when you have many services running independently and communicating with each other: how do services find each other, how do they share configuration settings, and how does the system track which services are healthy. In a microservices architecture, where an application is split into many small, independently deployable services, each service needs to know where to send requests to other services. Nacos acts as a central registry where services announce themselves when they start up, and look up the addresses of other services they need. This is called service discovery. When a service instance goes down or becomes unhealthy, Nacos detects it through health checks and removes it from the registry so traffic is not sent to it. Nacos also handles configuration management. Instead of each service having its own configuration files that require a redeployment to change, teams store configuration centrally in Nacos. When settings change, such as feature flags, database URLs, or timeout values, services pick up the new values in real time without restarting. This is particularly valuable in large deployments where redeploying dozens of services to change one setting is impractical. A third feature is DNS-based routing, allowing services to be discovered via DNS addresses rather than direct registry lookups, which can integrate with existing infrastructure patterns. You would use Nacos when building or operating a backend system composed of multiple services, especially in Java-heavy environments using frameworks like Dubbo or Spring Cloud. It integrates directly with Kubernetes and Istio for cloud-native deployments. The server runs as a standalone Java application and includes a web dashboard for managing services and configurations. It is widely used in Chinese tech companies and is an Alibaba open-source project.