spring cloud微服务分布式云架构--hystrix的使用

向右看齐 2022-03-02 02:40 209阅读 0赞

hystrix主要作用在服务消费者，进行应用的保护，当请求的服务请求超时时，做出相应的处理，避免客户端一直进行请求等待，避免在高并发的情况出现服务器死机（请求过多，内存不足）

接下来的通过一个案例对hystrix的使用进行说明，案例完成的功能：Spring Cloud大型企业分布式微服务云架构源码请加一七九一七四三三八零

服务消费者根据Id调用服务提供者的接口，获取User表单的对应的记录，若请求超时则返回id为-1的User记录

一、基于Ribbon

<parent>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-parent</artifactId>
          <version>1.5.2.RELEASE</version>
          <relativePath/> 
      </parent>
     
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.version>1.8</java.version>
        <mybatis-spring-boot.version>1.2.0</mybatis-spring-boot.version>
        <mysql-connector.version>5.1.39</mysql-connector.version>
    </properties>
     
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
    		<groupId>org.springframework.cloud</groupId>
    		<artifactId>spring-cloud-starter-eureka</artifactId>
    		<version>1.3.5.RELEASE</version>
    	</dependency>
    	<dependency>
    	    <groupId>org.springframework.cloud</groupId>
    	    <artifactId>spring-cloud-starter-hystrix</artifactId>
    	    <version>1.3.5.RELEASE</version>
    	</dependency>
    	
    </dependencies>

2、application.yml

server:
      port: 8089
    spring:
      application:
        name: customer-user
    eureka:
      client: 
        serviceUrl: 
          defaultZone: http://user:zj123@localhost:8761/eureka
      instance:
        prefer-ip-address: true
        instance-id: ${spring.application.name}:${spring.cloud.client.ipAddress}:${spring.application.instance_id:${server.port}}
    provider-user: 
      ribbon: 
        NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule

3、Controller调用类

import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.http.MediaType;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.client.RestTemplate;
     
    import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
    import com.zhuojing.bean.User;
     
    @RestController
    public class UserController {
     
    	@Autowired
    	private RestTemplate restTemplate;
    	
    	
    	@GetMapping(value="/simple/{id}",produces=MediaType.APPLICATION_JSON_VALUE+";charset=utf-8")
    	@HystrixCommand(fallbackMethod = "findByIdFallback")
    	public User findUserById(@PathVariable Long id){
    		//服务提供者地址 PROVIDER-USER
    		return this.restTemplate.getForObject("http://PROVIDER-USER/simple/"+id, User.class);
    	}
    	/**
    	 * 断路器模式，当请求的消费者provider-user超时的情况下，就会直接调用此方法，此方法的参数和返回类型必须和findUserById方法一致，请求超时时间为1秒
    	 * @param id
    	 * @return
    	 */
    	public User findByIdFallback(Long id){
    		User user = new User();
    		user.setId(0L);
    		return user;
    	}
    	
    }

hystrix的默认的超时时间为1秒，若自定hystrix超时时间有一下两种方式

a、@HystrixCommand注解配置

@HystrixCommand(fallbackMethod = "findByIdFallback",commandProperties = {
         @HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds",value = "3000")
    })

b、在application.yml配置

hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds: 5000

4、启动类

import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;
    import org.springframework.cloud.client.loadbalancer.LoadBalanced;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    import org.springframework.cloud.netflix.ribbon.RibbonClient;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.ComponentScan;
    import org.springframework.context.annotation.FilterType;
    import org.springframework.web.client.RestTemplate;
     
    @SpringBootApplication
    @EnableEurekaClient
    @EnableCircuitBreaker
    public class AppCusRibbonPropertiesTest {
     
    	@Bean
    	@LoadBalanced
    	public RestTemplate restTemplate(){
    		return new RestTemplate();
    	}
    	public static void main(String[] args) {
    		SpringApplication.run(AppCusRibbonPropertiesTest.class, args);
    	}
    }

二、dashboard的使用

1、pom.xml

<parent>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-parent</artifactId>
          <version>1.5.2.RELEASE</version>
          <relativePath/> 
      </parent>
      <dependencies>
    		<dependency>
    			<groupId>org.springframework.cloud</groupId>
    			<artifactId>spring-cloud-starter-hystrix-dashboard</artifactId>
    			<version>1.3.5.RELEASE</version>
    		</dependency>
      </dependencies>

2、application.yml

server:  
port: 8030

3、启动类

import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.hystrix.dashboard.EnableHystrixDashboard;
     
    @EnableHystrixDashboard
    @SpringBootApplication
    public class DashboardApplication {
      public static void main(String[] args) {
        SpringApplication.run(DashboardApplication.class, args);
      }
    }

启动后访问：http:/ /localhost:8030/hystrix 进入首页，在地址栏上输入http:/ /localhost:8089/hystrix.stream（hystrix.stream）进行监控，在使用了hystrix的服务调用后才有数据。

三、Turbine的使用，Turbine是对微服务集群的监听

1、pom.xml

<parent>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-parent</artifactId>
          <version>1.5.2.RELEASE</version>
          <relativePath/> 
      </parent>
      <dependencies>
    	<dependency>
    		<groupId>org.springframework.cloud</groupId>
    		<artifactId>spring-cloud-starter-turbine</artifactId>
    		<version>1.3.5.RELEASE</version>
    	</dependency>
      </dependencies>

2、application.yml

server:
      port: 8031
    spring:
      application:
        name: microservice-hystrix-turbine
    eureka:
      client:
        serviceUrl:
          defaultZone: http://user:zj123@localhost:8761/eureka
      instance:
        prefer-ip-address: true
    turbine:
      aggregator:
        clusterConfig: default  #默认defualt，只有一个服务时候可以写服务名称的大写CUSTOMER-USER
      appConfig: customer-user
      clusterNameExpression: "'default'"

3、启动类

import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.turbine.EnableTurbine;
     
    @EnableTurbine
    @SpringBootApplication
    public class TurbineApplication {
      public static void main(String[] args) {
        SpringApplication.run(TurbineApplication.class, args);
      }
    }

hystrix 主页面中将localhost:8031/turbine.stream?cluster=CUSTOMER-USER填入，便可进行数据的图像化。