Mastering Nacos: Dynamic Service Discovery and Configuration for Cloud‑Native Apps

Overview

Nacos is an open‑source project launched by Alibaba that provides a simple and easy‑to‑use feature set to help you quickly achieve dynamic service discovery, service configuration, service metadata, and traffic management. Nacos is pronounced /nɑ:kəʊs/, and its full name is:

Na me and Co nfig S ervice

The core function of Nacos is service registration and dynamic configuration.

In Spring Cloud terms, you can think of it as:

Nacos = Spring Cloud Eureka + Spring Cloud Config

Service Registration

Nacos provides service registration and discovery capabilities. Service instances register on startup and deregister on shutdown, while clients query the registry to find available instances.

The service registry can also invoke health‑check APIs of service instances to verify they can handle requests.

Nacos supports the AP side of the CAP model, similar to Eureka, and offers a management console that is more active than Eureka’s community.

Usage steps:

(1) Add dependency spring-cloud-starter-alibaba-nacos-discovery (2) Add annotation to the main class @EnableDiscoveryClient (3) Configure core settings: service name and Nacos server address.

Dynamic Configuration

Dynamic configuration eliminates the need to redeploy applications when configuration changes, making configuration management more efficient and agile.

Centralized configuration simplifies building stateless services and enables elastic scaling on demand.

Nacos provides a simple UI console to help manage all service and application configurations.

Usage steps:

(1) Add dependency spring-cloud-starter-alibaba-nacos-config (2) Add automatic refresh annotation @RefreshScope (3) Configure core settings: service name and Nacos server address.

(4) Publish configuration via Nacos API.

Other Features

Health Check

Nacos provides real‑time health checks for services, preventing requests from being sent to unhealthy hosts or instances.

It supports transport‑layer (PING or TCP) and application‑layer (e.g., HTTP, MySQL, custom) health checks.

Nacos offers both agent‑reporting and server‑initiated health‑check modes.

A unified health‑check dashboard helps you manage service availability and traffic based on health status.

Dynamic DNS

Supports weighted routing, making it easier to implement middle‑layer load balancing, flexible routing policies, traffic control, and simple DNS resolution within data‑center networks.

It also simplifies DNS‑based service discovery.

Metadata Management

Metadata includes service endpoints, tags, version numbers, instance weights, routing rules, security policies, and other descriptive data.

Nacos can manage all services and metadata from a micro‑service platform perspective, covering service descriptions, lifecycle, static dependency analysis, health status, traffic management, routing, security policies, SLA, and key metrics.

Summary

Nacos centers on service and supports almost all mainstream service types, such as:

k8s

gRPC

Dubbo

Spring Cloud

Docker

It also provides a convenient Open‑API for extensions, and its documentation is relatively rich:

Official site: https://nacos.io/zh-cn/index.html

Source code: https://github.com/alibaba/nacos