Spring Cloud 服务注册，负载均衡
程序员文章站
2022-07-15 10:50:43
...
Eureka：注册中心（类似于Zookeeper）
Ribbon: 负载均衡，通过RestTemplate来发起url的请求。比如：restTemplate.getForEntity("http://COMPUTE-SERVICE/add?a=10&b=20", String.class).getBody();
Fegin: 负载均衡，通过接口来发起请求。类似于dubbo的那种调用方式
先启动Eureka注册中心，然后再启动一个提供者服务（COMPUTE-SERVICE），然后就可以通过Ribbon或者Fegin来调用COMPUTE-SERVICE了。
当用户发起客户端的请求时，请求到Ribbon后，它会通过RestTemplate来发起url的请求（请求COMPUTE-SERVICE）。
当用户发起客户端的请求时，请求到Fegin后，它会通过接口来发起请求（请求COMPUTE-SERVICE）。
工程结构如下图：
1. 启动Eureka
eureka-server工程源码
package com.didispace;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@EnableEurekaServer
@SpringBootApplication
public class Application {
public static void main(String[] args) {
new SpringApplicationBuilder(Application.class).web(true).run(args);
}
}application.properties
server.port=1111
#eureka.instance.hostname=localhost
eureka.client.register-with-eureka=false
eureka.client.fetch-registry=false
eureka.client.serviceUrl.defaultZone=http://localhost:${server.port}/eureka/pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.didispace</groupId>
<artifactId>eureka-server</artifactId>
<version>1.0.0</version>
<packaging>jar</packaging>
<name>eureka-server</name>
<description>Spring Cloud project</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.3.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka-server</artifactId>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Brixton.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
2. 启动服务compute-service
compute-service工程源码如下：
package com.didispace;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
@EnableDiscoveryClient
@SpringBootApplication
public class ComputeServiceApplication {
public static void main(String[] args) {
new SpringApplicationBuilder(ComputeServiceApplication.class).web(true).run(args);
}
}package com.didispace.web;
import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
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.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class ComputeController {
private final Logger logger = Logger.getLogger(getClass());
@Autowired
private DiscoveryClient client;
/**
* localhost:2222/add?a=1&b=1
* @param a
* @param b
* @return
*/
@RequestMapping(value = "/add" ,method = RequestMethod.GET)
public Integer add(@RequestParam Integer a, @RequestParam Integer b) {
ServiceInstance instance = client.getLocalServiceInstance();
Integer r = a + b;
logger.info("/add, host:" + instance.getHost() + ", service_id:" + instance.getServiceId() + ", result:" + r);
return r;
}
}application.properties
spring.application.name=compute-service
server.port=2222
eureka.client.serviceUrl.defaultZone=http://localhost:1111/eureka/
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.didispace</groupId>
<artifactId>compute-service</artifactId>
<version>1.0.0</version>
<packaging>jar</packaging>
<name>compute-service</name>
<description>Spring Cloud project</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.3.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Brixton.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
3. 启动Ribbon
eureka-ribbon工程源码：
package com.didispace;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
@SpringBootApplication
@EnableDiscoveryClient
@EnableCircuitBreaker
public class RibbonApplication {
@Bean
@LoadBalanced
RestTemplate restTemplate() {
return new RestTemplate();
}
public static void main(String[] args) {
SpringApplication.run(RibbonApplication.class, args);
}
}
package com.didispace.service;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;
@Service
public class ComputeService {
@Autowired
RestTemplate restTemplate;
@HystrixCommand(fallbackMethod = "addServiceFallback")
public String addService() {
return restTemplate.getForEntity("http://COMPUTE-SERVICE/add?a=10&b=20", String.class).getBody();
}
public String addServiceFallback() {
return "error";
}
}
package com.didispace.web;
import com.didispace.service.ComputeService;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import java.util.Map;
@RestController
public class ConsumerController {
@Autowired
private ComputeService computeService;
@RequestMapping(value = "/add", method = RequestMethod.GET)
public String add() {
return computeService.addService();
}
}application.properties
spring.application.name=ribbon-consumer
server.port=3333
eureka.client.serviceUrl.defaultZone=http://localhost:1111/eureka/
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.didispace</groupId>
<artifactId>eureka-ribbon</artifactId>
<version>1.0.0</version>
<packaging>jar</packaging>
<name>eureka-ribbon</name>
<description>Spring Cloud project</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.3.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-hystrix</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-ribbon</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</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>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Brixton.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
4. 查看服务注册情况：http://localhost:1111/
5. 发起请求http://localhost:3333/add
推荐阅读
-
Spring Cloud Alibaba | Sentinel: 服务限流高级篇
-
Spring Cloud第七篇 | 声明式服务调用Feign
-
[Spring cloud 一步步实现广告系统] 11. 使用Feign实现微服务调用
-
Nginx+Tomcat+Https 服务器负载均衡配置实践方案详解
-
详解基于Centos7+Nginx+Tomcat8的负载均衡服务器的搭建
-
微服务架构下使用Spring Cloud Zuul作为网关将多个微服务整合到一个Swagger服务上
-
Nginx配置实例-负载均衡实例：平均访问多台服务器
-
Nginx实现负载均衡时常用的分配服务器策略
-
Spring Cloud Alibaba | Nacos服务中心初探
-
spring cloud 入门系列八：使用spring cloud sleuth整合zipkin进行服务链路追踪