Eureka实战-1【Eureka Server在线扩容】
1、准备工作
PS：为了偷懒，每个pom文件都要依赖的公共依赖配置放在下面：
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.RELEASE</version>
<relativePath/>
</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>
1.1、由于需要动态修改配置，这里需要创建config-server工程，pom依赖如下：
<!-- 加上上面的公共依赖配置 -->
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-server</artifactId>
</dependency>
</dependencies> <build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
1.2、config-server工程启动类如下：
import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.config.server.EnableConfigServer; /** * 程序入口 */ @SpringBootApplication @EnableConfigServer public class ConfigServerApplication { public static void main(String[] args) { SpringApplication.run(ConfigServerApplication.class, args); } }
1.3、添加项目配置文件，资源路径：config-server\src\main\resources\bootstrap.yml
spring: application: name: config-server profiles: active: native server: port: 8888
这里如果不明白bootstrap.yml/properties与application.yml/properties的文件区别，这里推荐看一下这篇文章：https://blog.csdn.net/ThinkWon/article/details/100007093
为了便于演示效果，这里使用native的profile，即使用文件来存储配置，默认存放位置是resources\config目录下。另外为了演示eureka server的动态扩容，还需要创建eureka-server工程和eureka-client工程。
1.4、eureka-server工程，pom配置如下：
<!-- 加上上面的公共依赖配置 -->
<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>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
1.4.1、eureka-server工程启动类：
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); } }
1.4.2、eureka-server工程配置文件，路径：eureka-server\src\main\resources\bootstrap.yml，eureka-server\src\main\resources\application.yml
bootstrap.yml：
spring: application: name: eureka-server cloud: config: uri: http://localhost:8888 management: endpoints: web: exposure: include: '*'
application.yml：
eureka: server: peer-eureka-nodes-update-interval-ms: 10000 #默认是10分钟即600000，这里为了验证改为10秒， # 指定peerUpdateTask调度的时间间隔，用于从配置文件刷新peerEurekaNodes节点的配置信息
1.5、eureka-client工程，pom文件配置如下：
<!-- 加上上面的公共依赖配置 -->
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
1.5.1、eureka-client工程启动类：
import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.client.discovery.EnableDiscoveryClient; import org.springframework.cloud.netflix.eureka.EurekaClientConfigBean; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController @RequestMapping("/query") @SpringBootApplication @EnableDiscoveryClient public class EurekaClientApplication { public static void main(String[] args) { SpringApplication.run(EurekaClientApplication.class, args); } @Autowired private EurekaClientConfigBean eurekaClientConfigBean; @GetMapping("/eureka-server") public Object getEurekaServerUrl() { return eurekaClientConfigBean.getServiceUrl(); } }
1.5.2、eureka-client工程配置文件，路径：eureka-client\src\main\resources\bootstrap.yml，eureka-client\src\main\resources\application.yml
bootstrap.yml：
spring: application: name: eureka-client cloud: config: uri: http://localhost:8888 management: endpoints: web: exposure: include: '*'
application.yml：
eureka:
client:
eureka-service-url-poll-interval-seconds: 10 #默认为300秒，这里为了验证改为10秒
2、添加config-server配置文件
2.1、添加eureka-client配置文件，路径：config-server\src\main\resources\config\eureka-client.yml
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
2.2、添加eureka-server配置文件，路径：config-server\src\main\resources\config\eureka-server-peer1.yml，config-server\src\main\resources\config\eureka-server-peer2yml，config-server\src\main\resources\config\eureka-server-peer3.yml
config-server\src\main\resources\config\eureka-server-peer1.yml：
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
config-server\src\main\resources\config\eureka-server-peer2.yml：
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
config-server\src\main\resources\config\eureka-server-peer3.yml：
server: port: 8763 eureka: instance: hostname: localhost preferIpAddress: true client: registerWithEureka: true fetchRegistry: true serviceUrl: defaultZone: http://localhost:8761/eureka/,http://localhost:8762/eureka/ # three eureka server server: waitTimeInMsWhenSyncEmpty: 0 enableSelfPreservation: false
从配置文件可以看出，eureka-server一共有三个实例，都是两两互相注册，1-2、2-3、1-3。
3、启动工程
分别启动工程：config-server，eureka-server，eureka-client。
启动config-server命令：
mvn spring-boot:run
启动eureka-server命令：
mvn spring-boot:run -Dspring.profiles.active=peer1
mvn spring-boot:run -Dspring.profiles.active=peer2
mvn spring-boot:run -Dspring.profiles.active=peer3
按照profiles启动的时候会报错
2019-10-03 17:10:07.519 ERROR 15853 --- [ main] com.netflix.discovery.DiscoveryClient : DiscoveryClient_EUREKA-SERVER/10.2.240.30:eureka-server:8761 - was unable to refresh its cache! status = Cannot execute request on any known server com.netflix.discovery.shared.transport.TransportException: Cannot execute request on any known server at com.netflix.discovery.shared.transport.decorator.RetryableEurekaHttpClient.execute(RetryableEurekaHttpClient.java:112) ~[eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.getApplications(EurekaHttpClientDecorator.java:134) ~[eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator$6.execute(EurekaHttpClientDecorator.java:137) ~[eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.SessionedEurekaHttpClient.execute(SessionedEurekaHttpClient.java:77) ~[eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.getApplications(EurekaHttpClientDecorator.java:134) ~[eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.DiscoveryClient.getAndStoreFullRegistry(DiscoveryClient.java:1051) [eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.DiscoveryClient.fetchRegistry(DiscoveryClient.java:965) [eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.DiscoveryClient.<init>(DiscoveryClient.java:414) [eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.DiscoveryClient.<init>(DiscoveryClient.java:269) [eureka-client-1.9.2.jar:1.9.2] at org.springframework.cloud.netflix.eureka.CloudEurekaClient.<init>(CloudEurekaClient.java:63) [spring-cloud-netflix-eureka-client-2.0.0.RELEASE.jar:2.0.0.RELEASE] at org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration$RefreshableEurekaClientConfiguration.eurekaClient(EurekaClientAutoConfiguration.java:269) [spring-cloud-netflix-eureka-client-2.0.0.RELEASE.jar:2.0.0.RELEASE] at org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration$RefreshableEurekaClientConfiguration$$EnhancerBySpringCGLIB$$ee9298f0.CGLIB$eurekaClient$0(<generated>) [spring-cloud-netflix-eureka-client-2.0.0.RELEASE.jar:2.0.0.RELEASE] at org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration$RefreshableEurekaClientConfiguration$$EnhancerBySpringCGLIB$$ee9298f0$$FastClassBySpringCGLIB$$c9690964.invoke(<generated>) [spring-cloud-netflix-eureka-client-2.0.0.RELEASE.jar:2.0.0.RELEASE] at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) [spring-core-5.0.7.RELEASE.jar:5.0.7.RELEASE] at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:361) [spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE] at org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration$RefreshableEurekaClientConfiguration$$EnhancerBySpringCGLIB$$ee9298f0.eurekaClient(<generated>) [spring-cloud-netflix-eureka-client-2.0.0.RELEASE.jar:2.0.0.RELEASE] 2019-10-03 17:10:12.759 ERROR 15853 --- [nfoReplicator-0] c.n.d.s.t.d.RedirectingEurekaHttpClient : Request execution error com.sun.jersey.api.client.ClientHandlerException: java.net.ConnectException: Connection refused (Connection refused) at com.sun.jersey.client.apache4.ApacheHttpClient4Handler.handle(ApacheHttpClient4Handler.java:187) ~[jersey-apache-client4-1.19.1.jar:1.19.1] at com.sun.jersey.api.client.filter.GZIPContentEncodingFilter.handle(GZIPContentEncodingFilter.java:123) ~[jersey-client-1.19.1.jar:1.19.1] at com.netflix.discovery.EurekaIdentityHeaderFilter.handle(EurekaIdentityHeaderFilter.java:27) ~[eureka-client-1.9.2.jar:1.9.2] at com.sun.jersey.api.client.Client.handle(Client.java:652) ~[jersey-client-1.19.1.jar:1.19.1] at com.sun.jersey.api.client.WebResource.handle(WebResource.java:682) ~[jersey-client-1.19.1.jar:1.19.1] at com.sun.jersey.api.client.WebResource.access$200(WebResource.java:74) ~[jersey-client-1.19.1.jar:1.19.1] at com.sun.jersey.api.client.WebResource$Builder.post(WebResource.java:570) ~[jersey-client-1.19.1.jar:1.19.1] at com.netflix.discovery.shared.transport.jersey.AbstractJerseyEurekaHttpClient.register(AbstractJerseyEurekaHttpClient.java:56) ~[eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator$1.execute(EurekaHttpClientDecorator.java:59) [eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.MetricsCollectingEurekaHttpClient.execute(MetricsCollectingEurekaHttpClient.java:73) ~[eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.register(EurekaHttpClientDecorator.java:56) [eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator$1.execute(EurekaHttpClientDecorator.java:59) [eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.RedirectingEurekaHttpClient.executeOnNewServer(RedirectingEurekaHttpClient.java:118) ~[eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.RedirectingEurekaHttpClient.execute(RedirectingEurekaHttpClient.java:79) ~[eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.register(EurekaHttpClientDecorator.java:56) [eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator$1.execute(EurekaHttpClientDecorator.java:59) [eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.RetryableEurekaHttpClient.execute(RetryableEurekaHttpClient.java:120) [eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.register(EurekaHttpClientDecorator.java:56) [eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator$1.execute(EurekaHttpClientDecorator.java:59) [eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.SessionedEurekaHttpClient.execute(SessionedEurekaHttpClient.java:77) [eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.shared.transport.decorator.EurekaHttpClientDecorator.register(EurekaHttpClientDecorator.java:56) [eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.DiscoveryClient.register(DiscoveryClient.java:829) [eureka-client-1.9.2.jar:1.9.2] at com.netflix.discovery.InstanceInfoReplicator.run(InstanceInfoReplicator.java:121) [eureka-client-1.9.2.jar:1.9.2] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_151] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_151] at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) [na:1.8.0_151] at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) [na:1.8.0_151] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_151] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_151] at java.lang.Thread.run(Thread.java:748) [na:1.8.0_151]
这是因为这里为了后续演示扩容方便，peer1的fetchRegistry及fetchRegistry的属性设置为true的缘故，如果是standalone的eureka server，不想看到这个错误，可以自行设置为false。
访问：localhost:8761
可以看到，此时eureka-server已经有了三个实例。
启动eureka-client命令：
mvn spring-boot:run
访问：localhost:8081/query/eureka-server/
可以看到，得到是三个server实例，为了方便这里使用的是native的profile，如果有修改文件，需要重启后才能生效，如果使用的是git仓库或者是GitHub仓库，则无需重启config-server。
原文作者：KingJames、
原文地址: https://www.cnblogs.com/idoljames/p/11620140.html
本文转自网络文章，转载此文章仅为分享知识，如有侵权，请联系博主进行删除。
原文地址: https://www.cnblogs.com/idoljames/p/11620140.html
本文转自网络文章，转载此文章仅为分享知识，如有侵权，请联系博主进行删除。
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