spring cloud微服务分布式云架构--hystrix的使用

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


      org.springframework.boot
      spring-boot-starter-parent
      1.5.2.RELEASE
       
  
 

    UTF-8
    1.8
    1.2.0
    5.1.39

 

    
        org.springframework.boot
        spring-boot-starter-web
    
    
		org.springframework.cloud
		spring-cloud-starter-eureka
		1.3.5.RELEASE
	
	
	    org.springframework.cloud
	    spring-cloud-starter-hystrix
	    1.3.5.RELEASE
	
	


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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

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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;
	}
	
}

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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")
})

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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);
	}
}

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二、dashboard的使用

1、pom.xml


      org.springframework.boot
      spring-boot-starter-parent
      1.5.2.RELEASE
       
  
  
		
			org.springframework.cloud
			spring-cloud-starter-hystrix-dashboard
			1.3.5.RELEASE
		
  

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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);
  }
}

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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


      org.springframework.boot
      spring-boot-starter-parent
      1.5.2.RELEASE
       
  
  
	
		org.springframework.cloud
		spring-cloud-starter-turbine
		1.3.5.RELEASE
	
  

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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'"

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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);
  }
}

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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。

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