Spring Cloud Eureka動態擴容
阿新 • • 發佈：2018-11-04
前言
本文心得包括案例基於《重新定義》，動態擴容Eureka是為了不影響已執行服務的情況下進行擴容。
正文
利用了config進行統一管理了eureka服務的配置，首先建立一個父module，主要就是把web工程依賴的jar包含在內，pom如下
<groupId>cn.springcloud.book</groupId> <artifactId>ch3-1</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>pom</packaging> <name>ch3-1</name> <description>ch3-1</description> <modules> <module>ch3-1-config-server</module> <module>ch3-1-eureka-server</module> <module>ch3-1-eureka-client</module> </modules> <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> <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> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</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-test</artifactId> <scope>test</scope> </dependency> </dependencies>
然後在這個父module下建立ConfigServer 名為：ch3-1-config-server，pom如下
<parent> <groupId>cn.springcloud.book</groupId> <artifactId>ch3-1</artifactId> <version>0.0.1-SNAPSHOT</version> <relativePath>../pom.xml</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.cloud</groupId> <artifactId>spring-cloud-config-server</artifactId> </dependency> </dependencies>
當前configserver的main方法及配置檔案
@SpringBootApplication
@EnableConfigServer
public class Ch31ConfigServerApplication {
public static void main(String[] args) {
SpringApplication.run(Ch31ConfigServerApplication.class, args);
}
}spring: application: name: config-server profiles: active: native server: port: 8888
在resources下建立一個目錄叫 config，裡面建立三個yml檔案，這裡為了方便，我建了三個配置檔案。程式碼如下
第一個是eureka的客戶端配置檔案
server:
port: 8081
spring:
application:
name: eureka-client1
eureka:
client:
serviceUrl:
# defaultZone: http://localhost:8761/eureka/ # one eureka server
# defaultZone: http://localhost:8761/eureka/,http://localhost:8762/eureka/ # two eureka server
defaultZone: http://localhost:8761/eureka/,http://localhost:8762/eureka/,http://localhost:8763/eureka/ # three eureka server第二個是eureka服務的peer1檔案
server:
port: 8761
spring:
application:
name: eureka-server
eureka:
instance:
hostname: localhost
preferIpAddress: true
client:
registerWithEureka: true
fetchRegistry: true
serviceUrl:
# defaultZone: http://localhost:8761/eureka/ # one eureka server
# defaultZone: http://localhost:8762/eureka/ # two eureka server
defaultZone: http://localhost:8762/eureka/,http://localhost:8763/eureka/ # three eureka server
server:
waitTimeInMsWhenSyncEmpty: 0
enableSelfPreservation: false第三個是eureka服務的peer2檔案
server:
port: 8762
eureka:
instance:
hostname: localhost
preferIpAddress: true
client:
registerWithEureka: true
fetchRegistry: true
serviceUrl:
# defaultZone: http://localhost:8761/eureka/ # two eureka server
defaultZone: http://localhost:8761/eureka/,http://localhost:8763/eureka/ # three eureka server
server:
waitTimeInMsWhenSyncEmpty: 0
enableSelfPreservation: false建立EurekaServer 工程名：ch3-1-eureka-server
pom檔案
<groupId>cn.springcloud.book</groupId>
<artifactId>ch3-1-eureka-server</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>ch3-1-eureka-server</name>
<description>ch3-1-eureka-server</description>
<parent>
<groupId>cn.springcloud.book</groupId>
<artifactId>ch3-1</artifactId>
<version>0.0.1-SNAPSHOT</version>
<relativePath>../pom.xml</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.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
</dependencies>eureka服務的兩個配置檔案如下，分別是bootstrap.yml 和application.yml
spring:
application:
name: eureka-server
cloud:
config:
uri: http://localhost:8888
management:
endpoints:
web:
exposure:
include: '*'eureka:
server:
peer-eureka-nodes-update-interval-ms: 10000 #預設是10分鐘即600000，這裡為了驗證改為10秒main方法啟動類
@SpringBootApplication
@EnableEurekaServer
public class Ch31EurekaServerApplication {
public static void main(String[] args) {
SpringApplication.run(Ch31EurekaServerApplication.class, args);
}
}最後一個就是建立eurakaClient
他的配置檔案和eureka服務的兩個配置檔案都一樣分別是bootstrap.yml 和application.yml ，區別是
spring:
application:
name: eureka-client
eurekaClient 的啟動類
@SpringBootApplication
@EnableDiscoveryClient
public class Ch31EurekaClientApplication {
public static void main(String[] args) {
SpringApplication.run(Ch31EurekaClientApplication.class, args);
}
}現在所有程式碼都準備好了，我們來首先啟動configServer
然後，下面的操作很關鍵，大家一定跟上，我會說的很清楚的
啟動時會有報錯資訊，不要管，最後的結果是啟動成功就ok
訪問 http://localhost:8761/，可以看到註冊成功
下面就開始進行對eureka-server進行動態擴容了
我們來修改peer1檔案
然後修改peer2檔案
然後我們重啟config-server，使配置生效。然後用如下命令分別重新整理eureka-client以及eureka-server-peer1
分別訪問http://localhost:8761/ ，和http://localhost:8762/，這裡只截一個圖了。
動態擴容成功
注：對本文有異議或不明白的地方微信探討，wx：15524579896