Spring Cloud Eureka 部署高可用注册中心

两个 Eureka 注册中心部署在同一台主机上，每个注册中心监听不同的端口。

节点一：

节点1的 java 项目名称是 Eureka,使用了 Maven 管理项目。

<?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.example</groupId>
	<artifactId>Eureka</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>Eureka</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.3.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>Finchley.RELEASE</spring-cloud.version>
	</properties>

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

src/main/resources/application.properties:

spring.application.name=eureka-server
server.port = 1111
eureka.instance.prefer-ip-address=true
eureka.instance.ipAddress=127.0.0.1
eureka.instance.hostname=localhost
eureka.client.register-with-eureka=true
eureka.client.fetch-registry=true
#eureka.client.service-url.defaultZone=http://${eureka.instance.hostname}:${server.port}/eureka/,http://localhost:1112/eureka/
eureka.client.service-url.defaultZone=http://localhost:1112/eureka/,http://127.0.0.1:1111/eureka/
#eureka.instance.lease-renewal-interval-in-seconds=5
#eureka.instance.lease-expiration-duration-in-seconds=5
eureka.client.registry-fetch-interval-seconds=5

注意：

两个注册中心的主机名不能一样（我的理解是标示注册中心的主机或IP不能一致），如果主机名一样会导致两个注册中心通信出问题无法同步服务清单。由于两个注册中心在同一个主机上，所以第一个节点使用IP地址配置，第二个节点使用主机名配置。

EurekaApplication.java

package com.example.Eureka;

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

@EnableEurekaServer
@SpringBootApplication
public class EurekaApplication {

	public static void main(String[] args) {
		SpringApplication.run(EurekaApplication.class, args);
	}
}

节点二：

节点2的 java 项目名称是 Eurek2。

pom.xml

<?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.example</groupId>
	<artifactId>Eureka2</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>Eureka2</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.3.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>Finchley.RELEASE</spring-cloud.version>
	</properties>

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

src/main/resources/application.properties:

spring.application.name=eureka-server
server.port = 1112
#eureka.instance.prefer-ip-address=true
#eureka.instance.ipAddress=127.0.0.1
eureka.instance.hostname=localhost
eureka.client.register-with-eureka=true
eureka.client.fetch-registry=true
#eureka.client.service-url.defaultZone=http://${eureka.instance.hostname}:${server.port}/eureka/,http://localhost:1111/eureka/
eureka.client.service-url.defaultZone=http://127.0.0.1:1111/eureka/,http://localhost:1112/eureka/
#eureka.instance.lease-renewal-interval-in-seconds=5
#eureka.instance.lease-expiration-duration-in-seconds=5
eureka.client.registry-fetch-interval-seconds=5

EurekaApplication2:

package com.example.Eureka;

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

@EnableEurekaServer
@SpringBootApplication
public class EurekaApplication2 {

	public static void main(String[] args) {
		SpringApplication.run(EurekaApplication2.class, args);
	}
}

服务提供方：

pom.xml

<?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.example</groupId>
    <artifactId>server1</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>server1</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.13.RELEASE</version>  <!-- sprong boot 版本不能高于 1.5.13 否则会与spring-cloud-starter-eureka 1.4.4 版本不兼容 -->
        <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>
    </properties>

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

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

         
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
            <version>1.4.4.RELEASE</version>
        </dependency> 
        
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            <version>1.4.4.RELEASE</version>
       </dependency>
            
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <!--  <version>${log4j.version}</version>  -->
        </dependency>
        
     
    <dependency>
       <groupId>com.fasterxml.jackson.core</groupId>
       <artifactId>jackson-annotations</artifactId>
       <version>2.9.6</version>
    </dependency>
    
    <dependency>
       <groupId>com.fasterxml.jackson.core</groupId>
       <artifactId>jackson-core</artifactId>
       <version>2.9.6</version>
    </dependency>
    
    <dependency>
       <groupId>com.fasterxml.jackson.core</groupId>
       <artifactId>jackson-databind</artifactId>
       <version>2.9.6</version>
    </dependency>

    
    </dependencies>
    
    <dependencyManagement>
       <dependencies>
          <dependency>
             <groupId>org.springframework.cloud</groupId>
             <artifactId>spring-cloud-dependencies</artifactId>
             <version>Brixton.SR5</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>

src/main/resources/application.properties:

spring.application.name=hello-service
eureka.client.serviceUrl.defaultZone=http://localhost:1112/eureka/,http://localhost:1111/eureka/
eureka.client.registry-fetch-interval-seconds=5

HellApplication.java

package com.example.server1;

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

@EnableDiscoveryClient
@SpringBootApplication
public class HellApplication {
	public static void main(String[] args) {
		SpringApplication.run(HellApplication.class, args);
		System.out.println("Hell word");
	}
}

HelloController.java

package com.example.server1;


import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;


@RestController
public class HelloController {
	private final Logger logger = Logger.getLogger(HelloController.class);
	
	@Autowired
	private DiscoveryClient client;
	
	@RequestMapping(value="/hello",method = RequestMethod.GET)
	public String index() {
		ServiceInstance instance = client.getLocalServiceInstance();
		logger.info("/hello,host:" + instance.getHost() +", service_id:"
				+ instance.getServiceId());
		return "Hello World";
	}
	

}

 启动两个注册中心节点，然后启动服务提供者。通过  http://localhost:1111/ 或 http://localhost:1112/访问两个服务注册中心，都可以看到服务注册信息。