跳到主要内容
  1. 核心api
  2. 基于Euraka的注册中心

Spring Cloud服务注册与服务发现

版本信息

Spring Cloud : Hoxton.SR1

Spring Boot : 2.2.2.RELEASE

Zookeeper : 3.5.6

Consul : 1.6.3

Nacos: 1.1.4

核心api​

  • org.springframework.cloud.client.serviceregistry.ServiceRegistry 服务注册

    • org.springframework.cloud.client.serviceregistry.Registration 注册信息
      • org.springframework.cloud.client.ServiceInstance 服务实例信息

    服务注册只能单注册中心，不能多注册中心

  • org.springframework.cloud.client.discovery.DiscoveryClient 服务发现

    • org.springframework.cloud.client.ServiceInstance 服务实例信息

    默认实现：org.springframework.cloud.client.discovery.composite.CompositeDiscoveryClient，可以多种服务发现并行

基于Euraka的注册中心以及服务发现​

服务端​

应用​

  1. 添加pom依赖

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

    <!--eureka注册中心-->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>

  2. 配置文件application.yml

    spring:
      application:
        name: euraka-server
    server:
      port: 9090

    eureka:
      client:
        service-url:
          defaultZone: http://127.0.0.1:${server.port}/eureka/

  3. 启动类EurekaDiscoveryServerApplication

/**
 * Eureka 服务发现注册中心
 *
 * @author FelixFly <chenglinxu@yeah.net>
 * @date 2020/2/1
 */
@SpringBootApplication
@EnableEurekaServer
public class EurekaDiscoveryServerApplication {

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

Eureka 服务端访问地址： http://127.0.0.1:9090/

Spring Cloud Eureka 服务端配置类：org.springframework.cloud.netflix.eureka.server.EurekaServerConfigBean

Eureka 服务端端点: https://github.com/Netflix/eureka/wiki/Eureka-REST-operations

Spring Cloud Eureka 服务端 端点去掉版本信息即可，比如/eureka/v2/apps改成/eureka/apps

源码分析​

  • 分析@EnableEurekaServer

    @Target(ElementType.TYPE)
    @Retention(RetentionPolicy.RUNTIME)
    @Documented
    @Import(EurekaServerMarkerConfiguration.class)
    public @interface EnableEurekaServer {

    }

    @Configuration(proxyBeanMethods = false)
    public class EurekaServerMarkerConfiguration {

    	@Bean
    	public Marker eurekaServerMarkerBean() {
    		return new Marker();
    	}

    	class Marker {

    	}

    }

    导入了EurekaServerMarkerConfiguration配置信息，该配置注册了Marker的Bean，由前面的@EnableConfigServer得知，这个Marker的Bean是一个类EurekaServerAutoConfiguration的自动装配条件

  • 分析EurekaServerAutoConfiguration

    @Configuration(proxyBeanMethods = false)
    @Import(EurekaServerInitializerConfiguration.class)
    @ConditionalOnBean(EurekaServerMarkerConfiguration.Marker.class)
    @EnableConfigurationProperties({ EurekaDashboardProperties.class,
    		InstanceRegistryProperties.class })
    @PropertySource("classpath:/eureka/server.properties")
    public class EurekaServerAutoConfiguration implements WebMvcConfigurer{
        ...
    }

    导入了EurekaServerInitializerConfiguration配置信息

客户端​

  1. 添加pom依赖

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

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

  2. 配置文件application.yml(由于采用多个客户端，客户端采用profile进行区分)

    spring:
      application:
        name: discovery-client
    eureka:
      client:
        enabled: false
    --- # eureka profile
    spring:
      profiles: eureka
    server:
      port: 8090
    eureka:
      client:
        enabled: true
        service-url:
          defaultZone: http://127.0.0.1:9090/eureka/

  3. 启动类DiscoveryClientApplication

    /**
     * 服务发现客户端程序
     *
     * @author FelixFly <chenglinxu@yeah.net>
     * @date 2020/2/1
     */
    @SpringBootApplication
    //@EnableDiscoveryClient // 这个注解可以去掉
    public class DiscoveryClientApplication {

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

  4. 配置服务发现端点

    /**
     * {@link DiscoveryClient} 端点
     *
     * @author FelixFly <chenglinxu@yeah.net>
     * @date 2020/2/1
     */
    @RestController
    public class DiscoveryClientController {

        @Autowired
        private DiscoveryClient discoveryClient;


        @GetMapping("/services")
        public List<String> getServices() {
            return this.discoveryClient.getServices();
        }

        @GetMapping("/services/{serviceId}")
        public List<ServiceInstance> getInstances(@PathVariable String serviceId) {
            return this.discoveryClient.getInstances(serviceId);
        }


        @GetMapping("/services/{serviceId}/{instanceId}")
        public ServiceInstance getInstance(@PathVariable String serviceId,
                                           @PathVariable String instanceId) {
            return this.discoveryClient.getInstances(serviceId).stream()
                    .filter(serviceInstance -> serviceInstance.getInstanceId().equals(instanceId))
                    .findAny()
                    .orElseThrow(() -> new RuntimeException("无此[" + instanceId + "]对应的实例服务"));
        }
    }

    配置项目运行参数--spring.profiles.active=eureka进行启动

    端点访问：

    • http://127.0.0.1:8090/services 所有服务

      [
          "euraka-server",
          "discovery-client"
      ]

    • http://127.0.0.1:8090/services/discovery-client discovery-client服务下所有实例

      [{
              "host": "LAPTOP-DC0GJVN9",
              "port": 8090,
              "metadata": {
                  "management.port": "8090"
              },
              "secure": false,
              "instanceId": "LAPTOP-DC0GJVN9:discovery-client:8090",
              "uri": "http://LAPTOP-DC0GJVN9:8090",
              "serviceId": "DISCOVERY-CLIENT",
              "instanceInfo": {
                  "instanceId": "LAPTOP-DC0GJVN9:discovery-client:8090",
                  "app": "DISCOVERY-CLIENT",
                  "appGroupName": null,
                  "ipAddr": "192.168.43.160",
                  "sid": "na",
                  "homePageUrl": "http://LAPTOP-DC0GJVN9:8090/",
                  "statusPageUrl": "http://LAPTOP-DC0GJVN9:8090/actuator/info",
                  "healthCheckUrl": "http://LAPTOP-DC0GJVN9:8090/actuator/health",
                  "secureHealthCheckUrl": null,
                  "vipAddress": "discovery-client",
                  "secureVipAddress": "discovery-client",
                  "countryId": 1,
                  "dataCenterInfo": {
                      "@class": "com.netflix.appinfo.InstanceInfo$DefaultDataCenterInfo",
                      "name": "MyOwn"
                  },
                  "hostName": "LAPTOP-DC0GJVN9",
                  "status": "UP",
                  "overriddenStatus": "UNKNOWN",
                  "leaseInfo": {
                      "renewalIntervalInSecs": 30,
                      "durationInSecs": 90,
                      "registrationTimestamp": 1580651487603,
                      "lastRenewalTimestamp": 1580651487603,
                      "evictionTimestamp": 0,
                      "serviceUpTimestamp": 1580651487094
                  },
                  "isCoordinatingDiscoveryServer": false,
                  "metadata": {
                      "management.port": "8090"
                  },
                  "lastUpdatedTimestamp": 1580651487603,
                  "lastDirtyTimestamp": 1580651487044,
                  "actionType": "ADDED",
                  "asgName": null
              },
              "scheme": null
          }
      ]

    • http://127.0.0.1:8090/services/discovery-client/LAPTOP-DC0GJVN9:discovery-client:8090 discovery-client服务下LAPTOP-DC0GJVN9:discovery-client:8090实例具体信息

      {
          "host": "LAPTOP-DC0GJVN9",
          "port": 8090,
          "metadata": {
              "management.port": "8090"
          },
          "secure": false,
          "instanceId": "LAPTOP-DC0GJVN9:discovery-client:8090",
          "uri": "http://LAPTOP-DC0GJVN9:8090",
          "serviceId": "DISCOVERY-CLIENT",
          "instanceInfo": {
              "instanceId": "LAPTOP-DC0GJVN9:discovery-client:8090",
              "app": "DISCOVERY-CLIENT",
              "appGroupName": null,
              "ipAddr": "192.168.43.160",
              "sid": "na",
              "homePageUrl": "http://LAPTOP-DC0GJVN9:8090/",
              "statusPageUrl": "http://LAPTOP-DC0GJVN9:8090/actuator/info",
              "healthCheckUrl": "http://LAPTOP-DC0GJVN9:8090/actuator/health",
              "secureHealthCheckUrl": null,
              "vipAddress": "discovery-client",
              "secureVipAddress": "discovery-client",
              "countryId": 1,
              "dataCenterInfo": {
                  "@class": "com.netflix.appinfo.InstanceInfo$DefaultDataCenterInfo",
                  "name": "MyOwn"
              },
              "hostName": "LAPTOP-DC0GJVN9",
              "status": "UP",
              "overriddenStatus": "UNKNOWN",
              "leaseInfo": {
                  "renewalIntervalInSecs": 30,
                  "durationInSecs": 90,
                  "registrationTimestamp": 1580651487603,
                  "lastRenewalTimestamp": 1580651487603,
                  "evictionTimestamp": 0,
                  "serviceUpTimestamp": 1580651487094
              },
              "isCoordinatingDiscoveryServer": false,
              "metadata": {
                  "management.port": "8090"
              },
              "lastUpdatedTimestamp": 1580651487603,
              "lastDirtyTimestamp": 1580651487044,
              "actionType": "ADDED",
              "asgName": null
          },
          "scheme": null
      }

关于@EnableDiscoveryClient说明

Spring Cloud Commons provides the @EnableDiscoveryClient annotation. This looks for implementations of the DiscoveryClient and ReactiveDiscoveryClient interfaces with META-INF/ spring.factories. Implementations of the discovery client add a configuration class to spring.factories under the org.springframework.cloud.client.discovery.EnableDiscoveryClient key.

Spring Cloud基础提供@EnableDiscoveryClient,该注解查找META-INF/spring.factories下DiscoveryClient 和ReactiveDiscoveryClient接口的实现。服务发现的配置和实现在spring.factories中org.springframework.cloud.client.discovery.EnableDiscoveryClientkey下面。

@EnableDiscoveryClient is no longer required. You can put a DiscoveryClient implementation on the classpath to cause the Spring Boot application to register with the service discovery server.

@EnableDiscoveryClient不再是必须的。你可以将DiscoveryClient实现放到目录下来影响Spring Boot应用注册服务发现服务。

To enable the Sidecar, create a Spring Boot application with @EnableSidecar. This annotation includes @EnableCircuitBreaker, @EnableDiscoveryClient, and @EnableZuulProxy. Run the resulting application on the same host as the non-JVM application.

为了启用边车模式，创建Spring Boot 应用使用@EnableSidecar。该注解包含@EnableCircuitBreaker、@EnableDiscoveryClient和@EnableZuulProxy。在同一主机启动应用作为非JVM应用。

基于Zookeeper的注册中心以及服务发现​

服务端​

  1. 下载地址
  2. 解压并修改conf/zoo.cfg文件名
  3. 在bin/zkServer进行启动

客户端​

应用代码部分跟Eureka客户端相同

  1. 添加pom依赖

    <!--zookeeper 客户端-->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
    </dependency>

  2. 配置文件application.yml(由于采用多个客户端，客户端采用profile进行区分)

    spring:
      application:
        name: discovery-client
      cloud:
        zookeeper: # 关闭 zookeeper 服务发现
          enabled: false # 关闭zookeeper
          discovery:
            enabled: false
    eureka:
      client:
        enabled: false
    --- # eureka profile
    spring:
      profiles: eureka
    server:
      port: 8090
    eureka:
      client:
        enabled: true
        service-url:
          defaultZone: http://127.0.0.1:9090/eureka/

    --- # zookeeper profile
    spring:
      profiles: zookeeper
      cloud:
        zookeeper:
          connect-string: 127.0.0.1:2181
          enabled: true
          discovery:
            enabled: true
    server:
      port: 0

    配置项目运行参数--spring.profiles.active=zookeeper进行启动,由于配置采用server.port=0随机端口，根据启动日志来甄别启动端口（本机随机到的端口是57189）

    端点访问：

    • http://127.0.0.1:57189/services 所有服务

      [
          "discovery-client"
      ]

    • http://127.0.0.1:57189/services/discovery-client discovery-client服务下所有实例

      [{
              "serviceId": "discovery-client",
              "host": "LAPTOP-DC0GJVN9",
              "port": 57189,
              "secure": false,
              "uri": "http://LAPTOP-DC0GJVN9:57189",
              "metadata": {},
              "serviceInstance": {
                  "name": "discovery-client",
                  "id": "d6475c0a-e0ee-4deb-9c03-454c3186f264",
                  "address": "LAPTOP-DC0GJVN9",
                  "port": 57189,
                  "sslPort": null,
                  "payload": {
                      "id": "application-1",
                      "name": "discovery-client",
                      "metadata": {}
                  },
                  "registrationTimeUTC": 1580654720186,
                  "serviceType": "DYNAMIC",
                  "uriSpec": {
                      "parts": [{
                              "value": "scheme",
                              "variable": true
                          }, {
                              "value": "://",
                              "variable": false
                          }, {
                              "value": "address",
                              "variable": true
                          }, {
                              "value": ":",
                              "variable": false
                          }, {
                              "value": "port",
                              "variable": true
                          }
                      ]
                  },
                  "enabled": true
              },
              "instanceId": "d6475c0a-e0ee-4deb-9c03-454c3186f264",
              "scheme": null
          }
      ]

    • http://127.0.0.1:57189/services/discovery-client/d6475c0a-e0ee-4deb-9c03-454c3186f264 discovery-client服务下d6475c0a-e0ee-4deb-9c03-454c3186f264实例具体信息

      {
          "serviceId": "discovery-client",
          "host": "LAPTOP-DC0GJVN9",
          "port": 57189,
          "secure": false,
          "uri": "http://LAPTOP-DC0GJVN9:57189",
          "metadata": {},
          "serviceInstance": {
              "name": "discovery-client",
              "id": "d6475c0a-e0ee-4deb-9c03-454c3186f264",
              "address": "LAPTOP-DC0GJVN9",
              "port": 57189,
              "sslPort": null,
              "payload": {
                  "id": "application-1",
                  "name": "discovery-client",
                  "metadata": {}
              },
              "registrationTimeUTC": 1580654720186,
              "serviceType": "DYNAMIC",
              "uriSpec": {
                  "parts": [{
                          "value": "scheme",
                          "variable": true
                      }, {
                          "value": "://",
                          "variable": false
                      }, {
                          "value": "address",
                          "variable": true
                      }, {
                          "value": ":",
                          "variable": false
                      }, {
                          "value": "port",
                          "variable": true
                      }
                  ]
              },
              "enabled": true
          },
          "instanceId": "d6475c0a-e0ee-4deb-9c03-454c3186f264",
          "scheme": null
      }

    基于Consul的注册中心以及服务发现​

    服务端​

    1. 下载地址

    2. 解压

    3. 在Consul目录下执行consul agent -dev

      windows下是.\consul.exe agent -dev

    客户端​

    应用代码部分跟Eureka客户端相同

    1. 添加pom依赖

      <!--consul 客户端-->
      <dependency>
       <groupId>org.springframework.cloud</groupId>
          <artifactId>spring-cloud-starter-consul-discovery</artifactId>
      </dependency>

    2. 配置文件application.yml(由于采用多个客户端，客户端采用profile进行区分)

      spring:
        application:
          name: discovery-client
        cloud:
          zookeeper: # 关闭 zookeeper 服务发现
            enabled: false # 关闭zookeeper
            discovery:
              enabled: false
          consul: # 关闭 consul 服务发现
            discovery:
              register: false
              enabled: false
            enabled: false
      eureka:
        client:
          enabled: false
      --- # eureka profile
      spring:
        profiles: eureka
      server:
        port: 8090
      eureka:
        client:
          enabled: true
          service-url:
            defaultZone: http://127.0.0.1:9090/eureka/

      --- # zookeeper profile
      spring:
        profiles: zookeeper
        cloud:
          zookeeper:
            connect-string: 127.0.0.1:2181
            enabled: true
         discovery:
              enabled: true
      server:
        port: 0
      --- # consul profile
      spring:
       profiles: consul
        cloud:
          consul:
            enabled: true
            host: 127.0.0.1
            port: 8500
         discovery:
              register: true
           enabled: true
      server:
        port: 8191

      配置项目运行参数--spring.profiles.active=consul进行启动

      端点访问：

      • http://127.0.0.1:8191/services 所有服务

        [
            "consul",
            "discovery-client"
        ]

      • http://127.0.0.1:8191/services/discovery-client discovery-client服务下所有实例

        [{
                "instanceId": "discovery-client-8191",
                "serviceId": "discovery-client",
                "host": "LAPTOP-DC0GJVN9",
                "port": 8191,
                "secure": false,
                "metadata": {
                    "secure": "false"
                },
                "uri": "http://LAPTOP-DC0GJVN9:8191",
                "scheme": null
            }
        ]

      • http://127.0.0.1:8191/services/discovery-client/discovery-client-8191 discovery-client服务下discovery-client-8191实例具体信息

        {
            "instanceId": "discovery-client-8191",
            "serviceId": "discovery-client",
            "host": "LAPTOP-DC0GJVN9",
            "port": 8191,
            "secure": false,
            "metadata": {
                "secure": "false"
         },
            "uri": "http://LAPTOP-DC0GJVN9:8191",
         "scheme": null
        }

基于Nacos的注册中心以及服务发现​

服务端​

  1. 下载地址
  2. 解压
  3. 在bin/startup进行启动

客户端​

应用代码部分跟Eureka客户端相同

  1. 添加pom依赖

    <!--nacos 客户端-->
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        <version>2.1.1.RELEASE</version>
    </dependency>

  2. 配置文件application.yml(由于采用多个客户端，客户端采用profile进行区分)

    spring:
      application:
        name: discovery-client
      cloud:
        zookeeper: # 关闭 zookeeper 服务发现
          enabled: false # 关闭zookeeper
          discovery:
            enabled: false
        consul: # 关闭 consul 服务发现
          discovery:
            register: false
            enabled: false
          enabled: false
        nacos: # 关闭 nacos 服务发现
          discovery:
            enabled: false
    # 暴露所有端点
    management:
      endpoints:
        web:
          exposure:
            include: '*'
    eureka:
      client:
        enabled: false
    --- # eureka profile
    spring:
      profiles: eureka
    server:
      port: 8090
    eureka:
      client:
        enabled: true
        service-url:
       defaultZone: http://127.0.0.1:9090/eureka/
       --- # zookeeper profile
       spring:
      profiles: zookeeper
         cloud:
        zookeeper:
             connect-string: 127.0.0.1:2181
             enabled: true
             discovery:
               enabled: true
       server:
      port: 0
       --- # consul profile
    spring:
         profiles: consul
         cloud:
           consul:
             enabled: true
             host: 127.0.0.1
             port: 8500
             discovery:
               register: true
               enabled: true
       server:
         port: 8191
       --- # nacos profile
       spring:
         profiles: nacos
         cloud:
           nacos:
             discovery:
               enabled: true
               server-addr: http://127.0.0.1:8848/
       server:
         port: 0

配置项目运行参数--spring.profiles.active=nacos进行启动,由于配置采用server.port=0随机端口，根据启动日志来甄别启动端口（本机随机到的端口是57785）

端点访问：

  • http://127.0.0.1:57785/services 所有服务

    [
        "discovery-client"
    ]

  • http://127.0.0.1:57785/services/discovery-client discovery-client服务下所有实例

    [{
            "serviceId": "discovery-client",
            "host": "192.168.43.160",
            "port": 57785,
            "secure": false,
            "metadata": {
                "nacos.instanceId": "192.168.43.160#57785#DEFAULT#DEFAULT_GROUP@@discovery-client",
                "nacos.weight": "1.0",
                "nacos.cluster": "DEFAULT",
             "nacos.healthy": "true",
                "preserved.register.source": "SPRING_CLOUD"
         },
            "uri": "http://192.168.43.160:57785",
            "scheme": null,
            "instanceId": null
        }
    ]

    nacos的这个instanceId没有值，没办法获取单个的实例具体信息

注册中心总结​

特性\注册中心EurkaConsulZookeeperNacos
server.port随机端口默认不支持默认不支持支持支持
适用规模5K-10K<3K10K-20K100K-1000K
CAP模型AP（最终一致性）AP（最终一致性）CP未知待测定

server.port随机端口默认不支持说明：可以调整instanceId来支持，默认是应用名称、端口以及其他信息组成