Eureka實戰-2【構建Multi Zone Eureka Server】

工程pom中公共依賴 1、Eureka Server工程啟動4個實例，配置兩個zone，即zone1、zone2，每個zone都要2個eureka server實例，這個2個zone配置在同一個region上，即region-east。 1.1、eureka-server工程pom文件： 1.2、 ...

工程pom中公共依賴

<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>

<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>

1、Eureka Server工程

啟動4個實例，配置兩個zone，即zone1、zone2，每個zone都要2個eureka server實例，這個2個zone配置在同一個region上，即region-east。

1.1、eureka-server工程pom文件：

<!--加上文章頭部的公共依賴-->

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

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

1.2、eureka-server工程啟動類

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

@SpringBootApplication
@EnableEurekaServer
public class EurekaServerApplication {

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

1.3、eureka-server工程配置文件，路徑：eureka-server\src\main\resources\，分別有5個文件：application-zone1a.yml，application-zone1b.yml，application-zone2a.yml，application-zone2b.yml，application.yml

application-zone1a.yml：

server:
  port: 8761
spring:
  application:
    name: eureka-server
eureka:
  instance:
    hostname: localhost
    preferIpAddress: true
    metadataMap.zone: zone1
  client:
    register-with-eureka: true
    fetch-registry: true
    region: region-east
    service-url:
      zone1: http://localhost:8761/eureka/,http://localhost:8762/eureka/
      zone2: http://localhost:8763/eureka/,http://localhost:8764/eureka/
    availability-zones:
      region-east: zone1,zone2
  server:
      waitTimeInMsWhenSyncEmpty: 0
      enableSelfPreservation: false

application-zone1b.yml

server:
  port: 8762
spring:
  application:
    name: eureka-server
eureka:
  instance:
    hostname: localhost
    preferIpAddress: true
    metadataMap.zone: zone1
  client:
    register-with-eureka: true
    fetch-registry: true
    region: region-east
    service-url:
      zone1: http://localhost:8761/eureka/,http://localhost:8762/eureka/
      zone2: http://localhost:8763/eureka/,http://localhost:8764/eureka/
    availability-zones:
      region-east: zone1,zone2
  server:
      waitTimeInMsWhenSyncEmpty: 0
      enableSelfPreservation: false

application-zone2a.yml

server:
  port: 8763
spring:
  application:
    name: eureka-server
eureka:
  instance:
    hostname: localhost
    preferIpAddress: true
    metadataMap.zone: zone2
  client:
    register-with-eureka: true
    fetch-registry: true
    region: region-east
    service-url:
      zone1: http://localhost:8761/eureka/,http://localhost:8762/eureka/
      zone2: http://localhost:8763/eureka/,http://localhost:8764/eureka/
    availability-zones:
      region-east: zone1,zone2
  server:
      waitTimeInMsWhenSyncEmpty: 0
      enableSelfPreservation: false

application-zone2b.yml

server:
  port: 8764
spring:
  application:
    name: eureka-server
eureka:
  instance:
    hostname: localhost
    preferIpAddress: true
    metadataMap.zone: zone2
  client:
    register-with-eureka: true
    fetch-registry: true
    region: region-east
    service-url:
      zone1: http://localhost:8761/eureka/,http://localhost:8762/eureka/
      zone2: http://localhost:8763/eureka/,http://localhost:8764/eureka/
    availability-zones:
      region-east: zone1,zone2
  server:
      waitTimeInMsWhenSyncEmpty: 0
      enableSelfPreservation: false

application.yml

eureka:
  server:
    use-read-only-response-cache: false
    response-cache-auto-expiration-in-seconds: 10
management:
  endpoints:
    web:
      exposure:
        include: '*'

從上面的4個配置文件可以看出，我們通過eureka.instance.metadataMap.zone設置了每個實例所屬的zone，接下來使用這4個配置啟動4個eureka server實例：

//啟動命令
mvn spring-boot:run -Dspring.profiles.active=zone1a
mvn spring-boot:run -Dspring.profiles.active=zone1b
mvn spring-boot:run -Dspring.profiles.active=zone2a
mvn spring-boot:run -Dspring.profiles.active=zone2b

2、Eureka Client工程

這裡配置2個eureka clent，分別屬於zone1和zone2。

2.1、eureka-client工程pom文件

<!--加上文章頭部公共配置-->

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

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

2.1、eureka-client工程啟動類

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

@SpringBootApplication
@EnableDiscoveryClient
public class EurekaClientApplication {

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

2.2、eureka-client工程配置文件，路徑：eureka-client\src\main\resources\，共3個文件：application.yml，application-zone1.yml，application-zone2.yml

application.yml：

#這裡暴露所有的endpoints，便於後面驗證
management:
  endpoints:
    web:
      exposure:
        include: '*'

application-zone1.yml：

server:
  port: 8081
spring:
  application:
    name: client
eureka:
  instance:
    metadataMap.zone: zone1
  client:
    register-with-eureka: true
    fetch-registry: true
    region: region-east
    service-url:
      zone1: http://localhost:8761/eureka/,http://localhost:8762/eureka/
      zone2: http://localhost:8763/eureka/,http://localhost:8764/eureka/
    availability-zones:
      region-east: zone1,zone2

application-zone2.yml：

server:
  port: 8082
spring:
  application:
    name: client
eureka:
  instance:
    metadataMap.zone: zone2
  client:
    register-with-eureka: true
    fetch-registry: true
    region: region-east
    service-url:
      zone1: http://localhost:8761/eureka/,http://localhost:8762/eureka/
      zone2: http://localhost:8763/eureka/,http://localhost:8764/eureka/
    availability-zones:
      region-east: zone1,zone2

2.3、啟動eureka client，執行命令，啟動2個實例：

mvn spring-boot:run -Dspring.profiles.active=zone1
mvn spring-boot:run -Dspring.profiles.active=zone2

3、Zuul Gateway工程

這裡新建一個zuul網關工程，來演示metadataMap的zone屬性中ZoneAffinity特性。

3.1、zuul gateway工程，pom文件：

<!--加上文章頭部的公共依賴-->

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

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

3.2、zuul gateway工程啟動類：

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

@SpringBootApplication
@EnableDiscoveryClient
@EnableZuulProxy
public class ZuulGatewayApplication {

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

3.3、zuul gateway工程配置文件，路徑：zuul-gateway\src\main\resources\，一共3個文件：application.yml，application-zone1.yml，application-zone2.yml

application.yml：

spring:
  application:
    name: zuul-gateway
management:
  endpoints:
    web:
      exposure:
        include: '*'

application-zone1.yml：

server:
  port: 10001
eureka:
  instance:
    metadataMap.zone: zone1
  client:
    register-with-eureka: true
    fetch-registry: true
    region: region-east
    service-url:
      zone1: http://localhost:8761/eureka/,http://localhost:8762/eureka/
      zone2: http://localhost:8763/eureka/,http://localhost:8764/eureka/
    availability-zones:
      region-east: zone1,zone2

application-zone2.yml：

server:
  port: 10002
eureka:
  instance:
    metadataMap.zone: zone2
  client:
    register-with-eureka: true
    fetch-registry: true
    region: region-east
    service-url:
      zone1: http://localhost:8761/eureka/,http://localhost:8762/eureka/
      zone2: http://localhost:8763/eureka/,http://localhost:8764/eureka/
    availability-zones:
      region-east: zone1,zone2

3.4、啟動zuul gateway工程，一共2個實例，執行命令：

mvn spring-boot:run -Dspring.profiles.active=zone1
mvn spring-boot:run -Dspring.profiles.active=zone2

驗證ZoneAffinity，訪問：localhost:10001/client/actuator/env，結果：

訪問：localhost:10002/client/actuator/env，結果：

可以看出請求網關/client/actuator/env，訪問的是eureka client實例的/actuator/env介面，處於zone1的Gateway返回的activeProfiles為zone1，處於zone2的Gateway返回的activeProfiles是zone2。