SpringCloud Eureka安装和使用,SpringCloud使用Eureka作为服务注册中心


SpringCloud Eureka安装和使用,SpringCloud使用Eureka作为服务注册中心

================================

?Copyright 蕃薯耀 2021-03-08

https://www.cnblogs.com/fanshuyao/


一、Eureka功能点
server:Eureka Server(服务注册中心)
provider:Eureka Client(服务提供者)+Actuator(服务器监控)
consumer:Eureka Client(服务器消费者)+Actuator(服务器监控)+Ribbon(负载均衡)

二、Eureka server服务端
1、引入Pom依赖

<dependency>
<groupId>org.springframework.cloudgroupId>
<artifactId>spring-cloud-starter-netflix-eureka-serverartifactId>
<version>2.2.7.RELEASEversion>
dependency>

<dependency>
<groupId>cn.hutoolgroupId>
<artifactId>hutool-allartifactId>
<version>5.4.4version>
dependency>

2、application.properties文件配置

server.port=8501


spring.application.name=springCloud-eureka-server

#eureka服务端的实例名称,eureka8501.com需要修改host文件
eureka.instance.hostname=eureka8501.com
#客户端服务名
#eureka.instance.appname=${spring.application.name}
# 是否向注册中心注册自己,缺省:true
# 一般情况下,Eureka服务端是不需要再注册自己的,false表示不向注册中心注册自己
eureka.client.register-with-eureka=false
# 是否从Eureka获取注册信息,缺省:true
# 一般情况下,Eureka服务端是不需要的
eureka.client.fetch-registry=false
# Eureka服务器的地址,类型为HashMap,缺省的Key为 defaultZone;缺省的Value为 http://localhost:8761/eureka
#如果是单机,配置自己的地址:http://eureka8501.com:8501/eureka,同样可以配置成:http://${eureka.instance.hostname}:${server.port}/eureka
#如果是集群(服务端),在这里需要配置其他eureka server的地址,用逗号进行分隔,如http://192.168.170.11:7000/eureka,http://192.168.170.12:9000/eureka 
#格式为:http://${eureka.instance.hostname}:${server.port}/eureka
eureka.client.service-url.defaultZone=http://eureka8501.com:8501/eureka

#关闭自我保护机制,保证不可用服务被及时移除
eureka.server.enable-self-preservation=false
#3秒后移除
eureka.server.eviction-interval-timer-in-ms=3000


3、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 SpringCloudEurekaServer8501Application {

public static void main(String[] args) {
    SpringApplication.run(SpringCloudEurekaServer8501Application.class, args);
  }
}


三、Eureka provider - 服务提供者端
1、引入Pom依赖

<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-actuatorartifactId>
dependency>

<dependency> <groupId>org.springframework.cloudgroupId> <artifactId>spring-cloud-starter-netflix-eureka-clientartifactId> <version>2.2.7.RELEASEversion> dependency>

<dependency> <groupId>cn.hutoolgroupId> <artifactId>hutool-allartifactId> <version>5.4.4version> dependency>

2、application.properties文件配置

server.port=8601

spring.application.name=springCloud-eureka-server

#eureka实例名称
#eureka.instance.hostname=eureka8601.com
eureka.instance.instance-id=eureka8601
#路径显示IP地址
eureka.instance.prefer-ip-address=true
#eureka客户端向服务端发送心跳的时间间隔,单元为秒,默认为30秒
eureka.instance.lease-renewal-interval-in-seconds=2
#eureka服务端收到最后一次心跳等待的时间上限,超时将移除服务,单元为秒,默认为90秒
eureka.instance.lease-expiration-duration-in-seconds=5

#false表示向注册中心注册自己
eureka.client.register-with-eureka=true
#是否从Eureka抓取已有的注册信息,默认为true。单节点不用设置,集群必须设置为true,才能配置ribbon使用负载均衡
eureka.client.fetch-registry=true
#设置与Eureka server交互的地址查询服务和注册服务都需要依赖这个地址
eureka.client.service-url.defaultZone=http://eureka8501.com:8501/eureka
#集群配置
#eureka.client.service-url.defaultZone=http://eureka8501.com:8501/eureka,http://eureka8502.com:8501/eureka

3、启动类

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

@SpringBootApplication
@EnableEurekaClient
public class SpringCloudEurekaClient8601Application {

    public static void main(String[] args) {
        SpringApplication.run(SpringCloudEurekaClient8601Application.class, args);
    }

}

4、服务类

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class ClientController {

    @Value("${server.port}")
    private String serverPort;
    
    @Autowired
    private DiscoveryClient discoveryClient;
    
    @RequestMapping("/test")
    public Result test() {
        return Result.ok("端口:" + serverPort);
    }
    
    
    @RequestMapping("/discoveryClient")
    public Result discoveryClient() {
        List services = discoveryClient.getServices();
        for (String service : services) {
            System.out.println("===service = " + service);
            System.out.println("");
            
            List serviceInstances = discoveryClient.getInstances(service);
            for (ServiceInstance serviceInstance : serviceInstances) {
                System.out.println("+++getInstanceId = " + serviceInstance.getInstanceId());
                System.out.println("+++getHost = " + serviceInstance.getHost());
                System.out.println("+++getPort = " + serviceInstance.getPort());
                System.out.println("+++getUri = " + serviceInstance.getUri());
                System.out.println("");
            }
            System.out.println("-------------------------------------");
        }
        
        return Result.ok(discoveryClient);
    }    
}
import java.util.Date;

import cn.hutool.core.date.DateUtil;

public class Result {
    
    public static final String SUCCESS = "操作成功。";
    public static final String FAILURE = "操作失败!";
    
    private boolean result;
    private String timestamp;
    private String msg;
    private Object datas;
    
    private Result() {}
    
    public static Result ok() {
        return Result.ok(SUCCESS, null);
    }
    
    
    public static Result ok(Object datas) {
        return Result.ok(SUCCESS, datas);
    }
    
    
    public static Result okMsg(String msg) {
        return Result.ok(msg, null);
    }
    
    
    public static Result ok(String msg, Object datas) {
        Result result = new Result();
        result.setResult(true);
        result.setTimestamp(DateUtil.formatDateTime(new Date()));
        
        if(msg == null || msg == "" || msg.trim() == "") {
            result.setMsg(SUCCESS);
        }else {
            result.setMsg(msg);
        }
        
        result.setDatas(datas);
        return result;
    }
    
    public static Result fail() {
        return Result.fail(FAILURE, null);
    }
    
    
    public static Result failMsg(String msg) {
        return Result.fail(msg, null);
    }
    
    
    public static Result fail(Object datas) {
        return Result.fail(FAILURE, datas);
    }
    
    public static Result fail(String msg, Object datas) {
        Result result = new Result();
        result.setResult(false);
        result.setTimestamp(DateUtil.formatDateTime(new Date()));
        
        if(msg == null || msg == "" || msg.trim() == "") {
            result.setMsg(FAILURE);
        }else {
            result.setMsg(msg);
        }
        result.setDatas(datas);
        return result;
    }
    
    public boolean isResult() {
        return result;
    }
    public void setResult(boolean result) {
        this.result = result;
    }
    public String getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(String timestamp) {
        this.timestamp = timestamp;
    }

    public String getMsg() {
        return msg;
    }
    public void setMsg(String msg) {
        this.msg = msg;
    }
    public Object getDatas() {
        return datas;
    }
    public void setDatas(Object datas) {
        this.datas = datas;
    }
    

    public static void main(String[] args) {
        
    }
    
}


四、Eureka consumer - 服务消费者端
1、引入Pom依赖

<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-actuatorartifactId>
dependency>

<dependency>
    <groupId>org.springframework.cloudgroupId>
    <artifactId>spring-cloud-starter-netflix-eureka-clientartifactId>
    <version>2.2.7.RELEASEversion>
dependency>

<dependency>
    <groupId>cn.hutoolgroupId>
    <artifactId>hutool-allartifactId>
    <version>5.4.4version>
dependency>

2、application.properties文件配置

server.port=8701

spring.application.name=springCloud-eureka-web

#eureka服务端的实例名称
eureka.instance.hostname=eureka8701.com

#eureka实例名称
eureka.instance.instance-id=eureka8701
#路径显示IP地址
eureka.instance.prefer-ip-address=true
#eureka客户端向服务端发送心跳的时间间隔,单元为秒,默认为30秒
eureka.instance.lease-renewal-interval-in-seconds=2
#eureka服务端收到最后一次心跳等待的时间上限,超时将移除服务,单元为秒,默认为90秒
eureka.instance.lease-expiration-duration-in-seconds=5

#false表示向注册中心注册自己
eureka.client.register-with-eureka=false
#是否从Eureka抓取已有的注册信息,默认为true。单节点不用设置,集群必须设置为true,才能配置ribbon使用负载均衡
eureka.client.fetch-registry=true
#设置与Eureka server交互的地址查询服务和注册服务都需要依赖这个地址
eureka.client.service-url.defaultZone=http://eureka8501.com:8501/eureka

3、启动类

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

@SpringBootApplication
@EnableEurekaClient
public class SpringCloudEurekaWebApplication {

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

}

4、RestTemplate类

import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;

@Configuration
public class RestConfig {

    //@LoadBalanced实现负载均衡
    @Bean
    @LoadBalanced
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

5、服务请求类

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
@RequestMapping("/web")
public class TestController {

    //private String serviceUrl = "http://eureka8601.com:8601";
    //springCloud使用RestTemplate,如果使用了服务的地址,RestTemplate必须加上@LoadBalanced注解,不然会java.net.UnknownHostException
    private String serviceUrl = "http://SPRINGCLOUD-EUREKA-SERVER";
    
    @Autowired
    private RestTemplate restTemplate;
    
    @RequestMapping(value="/get", produces = MediaType.APPLICATION_JSON_VALUE)
    public Result get() {
        Result result = restTemplate.getForObject(serviceUrl + "/test", Result.class);
        return result;
    }
    
}

五、eureka配置项解析
1、eureka通用配置

# 应用名称,将会显示在Eureka界面的应用名称
spring.application.name=config-service
# 应用端口,Eureka服务端默认为:8761
server.port=3333

2、eureka.server前缀的配置项

# 是否允许开启自我保护模式,缺省:true
# 当Eureka服务器在短时间内丢失过多客户端时,自我保护模式可使服务端不再删除失去连接的客户端
eureka.server.enable-self-preservation = false

# Peer节点更新间隔,单位:毫秒
eureka.server.peer-eureka-nodes-update-interval-ms =

# Eureka服务器清理无效节点的时间间隔,单位:毫秒,缺省:60000,即60秒
eureka.server.eviction-interval-timer-in-ms = 60000


3、eureka.instance前缀的配置项

# 服务名,默认取 spring.application.name 配置值,如果没有则为 unknown
eureka.instance.appname = eureka-client

# 实例ID
eureka.instance.instance-id = eureka-client-instance1

# 应用实例主机名
eureka.instance.hostname = localhost

# 客户端在注册时使用自己的IP而不是主机名,缺省:false
eureka.instance.prefer-ip-address = false

# 应用实例IP
eureka.instance.ip-address = 127.0.0.1

# 服务失效时间,失效的服务将被剔除。单位:秒,默认:90
eureka.instance.lease-expiration-duration-in-seconds = 90

# 服务续约(心跳)频率,单位:秒,缺省30
eureka.instance.lease-renewal-interval-in-seconds = 30

# 状态页面的URL,相对路径,默认使用 HTTP 访问,如需使用 HTTPS则要使用绝对路径配置,缺省:/info
eureka.instance.status-page-url-path = /info

# 健康检查页面的URL,相对路径,默认使用 HTTP 访问,如需使用 HTTPS则要使用绝对路径配置,缺省:/health
eureka.instance.health-check-url-path = /health


4、eureka.client前缀的配置项

# Eureka服务器的地址,类型为HashMap,缺省的Key为 defaultZone;缺省的Value为 http://localhost:8761/eureka
# 如果服务注册中心为高可用集群时,多个注册中心地址以逗号分隔。 
eureka.client.service-url.defaultZone=http://${eureka.instance.hostname}:${server.port}/eureka

# 是否向注册中心注册自己,缺省:true
# 一般情况下,Eureka服务端是不需要再注册自己的
eureka.client.register-with-eureka = true

# 是否从Eureka获取注册信息,缺省:true
# 一般情况下,Eureka服务端是不需要的
eureka.client.fetch-registry = true

# 客户端拉取服务注册信息间隔,单位:秒,缺省:30
eureka.client.registry-fetch-interval-seconds = 30

# 是否启用客户端健康检查
eureka.client.health-check.enabled = true

# 
eureka.client.eureka-service-url-poll-interval-seconds = 60

# 连接Eureka服务器的超时时间,单位:秒,缺省:5
eureka.client.eureka-server-connect-timeout-seconds = 5

# 从Eureka服务器读取信息的超时时间,单位:秒,缺省:8
eureka.client.eureka-server-read-timeout-seconds = 8

# 获取实例时是否只保留状态为 UP 的实例,缺省:true
eureka.client.filter-only-up-instances = true

# Eureka服务端连接空闲时的关闭时间,单位:秒,缺省:30
eureka.client.eureka-connection-idle-timeout-seconds = 30

# 从Eureka客户端到所有Eureka服务端的连接总数,缺省:200
eureka.client.eureka-server-total-connections = 200

# 从Eureka客户端到每个Eureka服务主机的连接总数,缺省:50
eureka.client.eureka-server-total-connections-per-host = 50

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================================

?Copyright 蕃薯耀 2021-03-08

https://www.cnblogs.com/fanshuyao/