Why Choose Nacos Over Eureka? A Hands‑On Guide to Service Discovery, Config, and Cluster Setup

1. Nacos Advantages

Nacos provides a new choice for service registration and discovery beyond Eureka and Consul, offering out‑of‑the‑box simplicity and ease of use.

1.1 Comparison with Eureka

1. Eureka 2.0 source code is closed. 2. Nacos registers more instances than Eureka according to the official site. 3. Nacos uses the Raft protocol, giving its cluster stronger consistency than Eureka.

Raft, a distributed consensus algorithm published in 2013, is praised for its simplicity and ease of implementation compared to other algorithms.

Raft Data Consistency Strategy

Raft relies on a Leader node to ensure cluster data consistency. Clients send data to the Leader, which marks it as uncommitted, replicates it to Followers, waits for a majority response, then marks it as committed and acknowledges the client.

1.2 Comparison with Spring Cloud Config

Three major advantages

Spring Cloud Config often requires Git and Spring Cloud Bus for dynamic updates.

Spring Cloud Config lacks a visual interface.

Nacos Config uses long‑living connections for rapid configuration updates, outperforming Spring Cloud Config.

2. Spring Cloud Alibaba Suite

The suite includes three main components:

Nacos – dynamic service discovery, configuration, and service management platform.

Sentinel – traffic‑based flow control, circuit breaking, and system load protection.

AliCloud OSS – scalable, secure, low‑cost object storage.

Component mapping with Spring Cloud Netflix:

Nacos = Eureka/Consul + Config + Admin

Sentinel = Hystrix + Dashboard + Turbine

Dubbo = Ribbon + Feign

RocketMQ = RabbitMQ

Schedulerx = Quartz

3. Nacos Architecture and Installation

3.1 Architecture

Nacos combines service registry, configuration center, and service management, similar to a fusion of Eureka/Consul, Config, and Admin.

3.2 Server Download and Installation

Installation tutorial: https://www.cnblogs.com/crazymakercircle/p/11992539.html

4. Running Nacos Server

4.1 Two Modes

standalone

cluster

4.2 Standalone Mode

Used for demos and testing; run without configuration changes: sh bin/startup.sh -m standalone On Windows: cmd bin/startup.cmd -m standalone Access the console at http://cdh1:8848/nacos/index.html (default username/password: nacos nacos).

4.3 Cluster Mode

Suitable for production; requires MySQL and two configuration files ( conf/cluster.conf and conf/application.properties).

conf/cluster.conf<br/>conf/application.properties

Example cluster.conf:

# IP list<br/>10.10.109.214<br/>11.16.128.34<br/>11.16.128.36

MySQL configuration in application.properties:

db.num=1<br/>db.url.0=jdbc:mysql://localhost:3306/nacos_config?characterEncoding=utf8&connectTimeout=1000&socketTimeout=3000&autoReconnect=true<br/>db.user=root<br/>db.password=root

Cluster mode stores data in MySQL; standalone mode stores data in an embedded Derby database located at NACOS_PATH/data/derby-data.

Note: MySQL 8.0 is not supported.

5. Practical Demo 1 – Using Nacos as a Service Registry

5.1 Project Structure

Two modules: service-provider-demo and service-consumer-demo.

5.2 Adding Nacos Client Dependency

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>

5.3 Provider Service

Enable discovery with @EnableDiscoveryClient and expose a simple REST endpoint:

package com.crazymaker.cloud.nacos.demo.controller;

@RestController
@RequestMapping("/echo")
public class EchoController {
    @RequestMapping(value="/{string}", method=RequestMethod.GET)
    public String echo(@PathVariable String string) {
        return "echo: " + string;
    }
}

Configuration (application.yml):

spring:
  application:
    name: service-provider-demo
  cloud:
    nacos:
      discovery:
        server-addr: ${NACOS_SERVER:cdh1:8848}
server:
  port: 18080

5.4 Consumer Service

Use Feign client to call the provider:

@FeignClient(name="service-provider-demo")
public interface EchoClient {
    @GetMapping("/echo/{string}")
    String echo(@PathVariable("string") String string);
}

Controller:

@RestController
@RequestMapping("/echo")
public class EchoConsumerController {
    @Resource
    EchoClient echoClient;
    @GetMapping("/{string}")
    public String echoRemoteEcho(@PathVariable String string) {
        return "provider echo is:" + echoClient.echo(string);
    }
}

Configuration (application.yml):

spring:
  application:
    name: sevice-consumer-demo
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
server:
  port: 18081

Access via Swagger UI at http://localhost:18080/provider/swagger-ui.html and http://localhost:18081/consumer/swagger-ui.html.

6. Practical Demo 2 – Using Nacos as a Configuration Center

6.1 Core Concepts

Profile : environment‑specific configuration (dev, test, prod).

Data ID : each profile maps to a Data ID in Nacos (format: ${prefix}-${spring.profiles.active}.${file-extension}).

Group : default DEFAULT_GROUP, can be customized for organization.

6.2 Adding Config Dependency

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
</dependency>

6.3 Bootstrap Configuration (bootstrap.yml)

spring:
  application:
    name: nacos-config-demo-provider
  profiles:
    active: dev
  cloud:
    nacos:
      discovery:
        server-addr: ${NACOS_SERVER:cdh1:8848}
      config:
        server-addr: ${NACOS_SERVER:cdh1:8848}
        prefix: nacos-config-demo
        group: DEFAULT_GROUP
        file-extension: yaml
server:
  port: 18083
  servlet:
    context-path: /config

6.4 Sample Controller

@RestController
@RequestMapping("/config")
public class ConfigGetController {
    @Value("${foo.bar:empty}")
    private String bar;
    @Value("${spring.datasource.username:empty}")
    private String dbusername;
    @GetMapping("/bar")
    public String getBar() { return "bar is :" + bar; }
    @GetMapping("/dbusername")
    public String getDbusername() { return "db username is :" + dbusername; }
}

Access via Swagger UI at http://localhost:18083/config/swagger-ui.html to view configuration values retrieved from Nacos.

7. Configuration Isolation

Isolation can be achieved via Nacos server address, namespace ID, and group name, allowing separation by environment, project, or module.

8. Nacos Cluster Deployment

IP Planning

Deploy three instances locally (nacos, nacos1, nacos2) with ports 8848, 8847, 8846 and configure MySQL as the data source in conf/application.properties.

spring.datasource.platform=mysql
db.num=1
db.url.0=jdbc:mysql://localhost:3306/nacos?characterEncoding=utf8&connectTimeout=1000&socketTimeout=3000&autoReconnect=true
db.user=root
db.password=123456

Cluster Configuration

Create conf/cluster.conf with the three node addresses:

127.0.0.1:8848
127.0.0.1:8847
127.0.0.1:8846

Start each instance with ./startup.sh; the default mode is cluster.

Reverse Proxy (Nginx) for High Availability

upstream nacos_server {
  server 127.0.0.1:8848;
  server 127.0.0.1:8847;
  server 127.0.0.1:8846;
}
server {
  listen 8648;
  location / {
    proxy_pass http://nacos_server;
  }
}

Access the clustered console via http://localhost:8648/nacos/#/clusterManagement.

Conclusion

Nacos offers a unified solution for service discovery and configuration management in cloud‑native microservice architectures, supporting both standalone and clustered deployments, with flexible isolation mechanisms and easy integration into Spring Cloud Alibaba projects.