Spring Cloud eureka 高可用-优快云博客

本文详细介绍如何使用Spring Cloud Eureka搭建服务发现与注册中心，包括服务端和客户端的配置，以及如何在本地模拟运行两个Eureka Server实现集群搭建。

服务端配置

pom.xml文件如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.neo</groupId>
	<artifactId>spring-cloud-eureka-two</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>spring-cloud-eureka-two</name>
	<description>Demo project for Spring cloud eureka</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.5.3.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
		<spring-cloud.version>Dalston.RELEASE</spring-cloud.version>
	</properties>

	<dependencies>
		<!--<dependency>-->
			<!--<groupId>org.springframework.cloud</groupId>-->
			<!--<artifactId>spring-cloud-starter</artifactId>-->
		<!--</dependency>-->
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-eureka-server</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-dependencies</artifactId>
				<version>${spring-cloud.version}</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
	</dependencyManagement>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>


</project>
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application.properties如下：

spring.application.name=spring-cloud-eureka

application-peer1.properties如下：

server.port=8000
eureka.instance.hostname=server1
eureka.client.register-with-eureka=true
eureka.client.fetch-registry=true
eureka.client.serviceUrl.defaultZone=http://server2:8001/eureka/
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application-peer2.properties如下：

server.port=8001
eureka.instance.hostname=server2

eureka.client.register-with-eureka=true
eureka.client.fetch-registry=true
eureka.client.serviceUrl.defaultZone=http://server1:8000/eureka/
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启动类增加@EnableEurekaServer注解即可

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@SpringBootApplication
@EnableEurekaServer
public class SpringCloudEurekaApplication {

	public static void main(String[] args) {
		SpringApplication.run(SpringCloudEurekaApplication.class, args);
	}
}
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客户端配置

pom文件如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.didispace</groupId>
	<artifactId>eureka-client</artifactId>
	<version>1.0.0</version>
	<packaging>jar</packaging>

	<name>eureka-client</name>
	<description>Spring Cloud In Action</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.5.4.RELEASE</version>
		<relativePath/>
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-eureka</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<!--<dependency>-->
			<!--<groupId>org.springframework.boot</groupId>-->
			<!--<artifactId>spring-boot-starter-actuator</artifactId>-->
		<!--</dependency>-->
	</dependencies>

	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-dependencies</artifactId>
				<version>Dalston.SR1</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
	</dependencyManagement>
	
	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>
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application.properties配置如下：

spring.application.name=eureka-client
server.port=2001

eureka.client.serviceUrl.defaultZone=http://localhost:8000/eureka/,http://localhost:8001/eureka
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启动类增加@EnableDiscoveryClient注解即可。

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@EnableDiscoveryClient
@SpringBootApplication
public class EurekaClientApplication {

	public static void main(String[] args) {
		new SpringApplicationBuilder(EurekaClientApplication.class).web(true).run(args);
	}

}
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Controller层

@RestController
public class DcController {

    @Autowired
    DiscoveryClient discoveryClient;

    @GetMapping("/dc")
    public String dc() {
        String services = "Services: " + discoveryClient.getServices();
        System.out.println(services);
        return services;
    }

}
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本机模拟运行2个Server，需要在hosts文件增加：

127.0.0.1 server1

127.0.0.1 server2

通过设置Program arguments参数启动2个Server端

启动后server1注册结果如下：

server2类似，通过Client端能够正常访问。

停止server1后，server2控制台报错Connect to server1:8000 timed out，但依然能够提供服务，是由于注册信息已经同步server2.