总述
分布式暴露的问题
Hystrix的定义
Hystrix的三个重要概念
-
服务降级(fallback)
-
服务熔断(break)
-
服务限流(flowlimmit)
模块构建
新建模块:cloud-provider-hystrix-payment8001
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">
<parent>
<artifactId>cloud201230</artifactId>
<groupId>com.banana</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>cloud-provider-hystrix-payment8001</artifactId>
<dependencies>
<!--hystrix-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
</dependency>
<!--引入eureka客户端-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<!--引入自定义的api通用包,可以使用Payment支付Entity-->
<dependency>
<groupId>com.banana</groupId>
<artifactId>cloud-api-commons</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<!--热部署-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>cn.hutool</groupId>
<artifactId>hutool-all</artifactId>
<version>5.1.1</version>
</dependency>
</dependencies>
</project>
application.yml
server:
port: 8001
spring:
application:
name: cloud-provider-hystrix-payment
eureka:
client:
register-with-eureka: true #是否将自己注册到注册中心,集群必须设置为true配合ribbon
fetch-registry: true #是否从服务端抓取已有的注册信息
service-url:
defaultZone: http://localhost:7001/eureka
#defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka
PaymentHystrixMain8001 主启动类
package com.banana.springcloud;
import com.netflix.hystrix.contrib.metrics.eventstream.HystrixMetricsStreamServlet;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.context.annotation.Bean;
/**
* Hystrix演示类
* @author layman
* @date 2021/1/18
*/
@SpringBootApplication
@EnableEurekaClient
@EnableCircuitBreaker
public class PaymentHystrixMain8001 {
public static void main(String[] args) {
SpringApplication.run(PaymentHystrixMain8001.class,args);
}
/**
* 此配置是为了服务监控而配置,与服务器容错本身无关,springCloud升级后的坑
* ServletRegistrationBean因为springBoot的默认路径不是/hystrix.stream
* 只要在自己的项目里配置上下文的servlet就可以了
*/
@Bean
public ServletRegistrationBean getServlet() {
HystrixMetricsStreamServlet streamServlet = new HystrixMetricsStreamServlet();
ServletRegistrationBean<HystrixMetricsStreamServlet> registrationBean = new ServletRegistrationBean<>(streamServlet);
registrationBean.setLoadOnStartup(1);
registrationBean.addUrlMappings("/hystrix.stream");
registrationBean.setName("HystrixMetricsStreamServlet");
return registrationBean;
}
}
PaymentService
package com.banana.springcloud.service;
/**
* @author layman
* @date 2021/1/18
*/
public interface PaymentService {
String paymentSuccess(Integer id);
String paymentTimeOut(Integer id);
String paymentCircuitBreaker(Integer id);
}
PaymentServiceImpl
package com.banana.springcloud.service.impl;
import cn.hutool.core.util.IdUtil;
import com.banana.springcloud.service.PaymentService;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixProperty;
import org.springframework.stereotype.Service;
import org.springframework.web.bind.annotation.PathVariable;
import java.util.concurrent.TimeUnit;
/**
* @author layman
* @date 2021/1/18
*/
@Service
public class PaymentServiceImpl implements PaymentService {
/**
* 模拟正常访问
* @param id
* @return String
*/
@Override
public String paymentSuccess(Integer id) {
return "线程名称: " + Thread.currentThread().getName() +
",方法名:paymentSuccess, id: " + id + " O(∩_∩)O哈哈~";
}
/**
* 模拟超时操作
* fallbackMethod:服务降级后的回调方法(超时异常or运行异常都会触发)
* commandProperties:
* isolation.thread.timeoutInMilliseconds:配置HystrixCommand执行的超时时间,单位为毫秒。
* @param id
* @return String
*/
@Override
@HystrixCommand(fallbackMethod = "paymentTimeOutHandler", commandProperties = {
@HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds", value = "3000")
})
public String paymentTimeOut(Integer id) {
int timeNumber = 5000;
//timeNumber = 10/0;
try {
TimeUnit.MILLISECONDS.sleep(timeNumber);
} catch (InterruptedException e) {
e.printStackTrace();
}
return "线程名称: " + Thread.currentThread().getName() +
" ,方法名:paymentTimeOut, id: " + id + " ,超时了~ 耗时:" + timeNumber + "毫秒";
}
/**
* =========================== 服务降级 ===========================
* 服务降级的处理方法
* paymentTimeOutHandler与paymentTimeOut的参数列表要对应上,否则会报错
*/
public String paymentTimeOutHandler(Integer id) {
return "线程名称: " + Thread.currentThread().getName() +
" ,系统繁忙系统报错 ,paymentInfo_TimeOutHandler ,请稍后再试 ,id: " + id + "\t " + "o(╥﹏╥)o";
}
/**
* =========================== 服务熔断 ===========================
* 服务的降级->进而熔断->恢复调用链路
* 如果在10秒钟的时间窗口期内,8次请求失败率达到60%,触发熔断,5秒钟(默认)后,进入半开状态,尝试放行请求
*/
@Override
@HystrixCommand(fallbackMethod = "paymentCircuitBreakerFallback", commandProperties = {
@HystrixProperty(name = "circuitBreaker.enabled", value = "true"), //是否开启断路器
@HystrixProperty(name = "circuitBreaker.requestVolumeThreshold", value = "8"), //请求次数,默认为20
@HystrixProperty(name = "circuitBreaker.sleepWindowInMilliseconds", value = "10000"), //时间窗口期,默认为10秒
@HystrixProperty(name = "circuitBreaker.errorThresholdPercentage", value = "60"),//失败率达到多少后触发熔断,默认为50
})
public String paymentCircuitBreaker(Integer id) {
if (id < 0) {
throw new RuntimeException("******id 不能为负数");
}
String serialNumber = IdUtil.simpleUUID(); //不带-的UUID
return Thread.currentThread().getName() + "\t" + "调用成功,流水号:" + serialNumber;
}
public String paymentCircuitBreakerFallback(Integer id) {
return "id 不能为负数,请稍后再试,o(╥﹏╥)o, id:" + id;
}
@HystrixCommand(fallbackMethod = "xxx_method",
groupKey = "strGroupCommand",
commandKey = "strCommarld",
threadPoolKey = "strThreadPool",
commandProperties = {
//设置隔离策略,THREAD 表示线程她SEMAPHORE:信号他隔离
@HystrixProperty(name = "execution.isolation.strategy", value = "THREAD"),
//当隔离策略选择信号他隔离的时候,用来设置信号地的大小(最大并发数)
@HystrixProperty(name = "execution.isolation.semaphore.maxConcurrentRequests", value = "10"),
//配置命令执行的超时时间
@HystrixProperty(name = "execution.isolation.thread.timeoutinMilliseconds", value = "10"),
//是否启用超时时间
@HystrixProperty(name = "execution.timeout.enabled", value = "true"),
//执行超时的时候是否中断
@HystrixProperty(name = "execution.isolation.thread.interruptOnTimeout", value = "true"),
//执行被取消的时候是否中断
@HystrixProperty(name = "execution.isolation.thread.interruptOnCancel", value = "true"),
//允许回调方法执行的最大并发数
@HystrixProperty(name = "fallback.isolation.semaphore.maxConcurrentRequests", value = "10"),
//服务降级是否启用,是否执行回调函数
@HystrixProperty(name = "fallback.enabled", value = "true"),
@HystrixProperty(name = "circuitBreaker.enabled", value = "true"),
//该属性用来设置在滚动时间窗中,断路器熔断的最小请求数。例如,默认该值为20的时候,
//如果滚动时间窗(默认10秒)内仅收到了19个请求,即使这19个请求都失败了, 断路器也不会打开。
@HystrixProperty(name = "circuitBreaker.requestVolumeThreshold", value = "20"),
// 该属性用来设置在熔动时间窗中表示在滚动时间窗中,在请求数量超过
// circuitBreaker.requestVolumeThreshold 的情况下,如果错误请求数的百分比超过50,
//就把断路器设置为“打开”状态,否则就设置为“关闭”状态。
@HystrixProperty(name = "circuitBreaker.errorThresholdPercentage", value = "50"),
// 该属性用来设置当断路器打开之后的休眠时间窗。休眠时间窗结束之后,
//会将断路器置为"半开”状态,尝试熔断的请求命令,如果低然失败就将断路器继续设置为"打开”状态,
//如果成功就设置为"关闭”状态。
@HystrixProperty(name = "circuitBreaker.sleepWindowinMilliseconds", value = "5009"),
//断路器强制打开
@HystrixProperty(name = "circuitBreaker.force0pen", value = "false"),
// 断路器强制关闭
@HystrixProperty(name = "circuitBreaker.forceClosed", value = "false"),
//滚动时间窗设置,该时间用于断路器判断健康度时需要收集信息的持续时间
@HystrixProperty(name = "metrics.rollingStats.timeinMilliseconds", value = "10000"),
//该属性用来设置滚动时间窗统计指标信息时划分”桶"的数量,断路器在收集指标信息的时候会根据设置的时间窗长度拆分成多个"相"来累计各度量值,每个”桶"记录了-段时间内的采集指标。
//比如10秒内拆分成10个”桶"收集这样,所以timeinMilliseconds 必须能被numBuckets 整除。否则会抛异常
@HystrixProperty(name = "metrics.rollingStats.numBuckets", value = "10"),
//该属性用来设置对命令执行的延迟是否使用百分位数来跟踪和计算。如果设置为false,那么所有的概要统计都将返回-1.
@HystrixProperty(name = "metrics .rollingPercentile.enabled", value = "false"),
//该属性用来设置百分位统计的滚动窗口的持续时间, 单位为毫秒。
@HystrixProperty(name = "metrics.rollingPercentile.timeInMilliseconds", value = "60000"),
//该属性用来设置百分位统计演动窗口中使用“桶”的数量。
@HystrixProperty(name = "metrics.rollingPercentile.numBuckets", value = "60000"),
// 该属性用来设置在执行过程中每个 “桶”中保留的最大执行次数。如果在滚动时间窗内发生超过该设定值的执行次数,就从最初的位置开始重写。例如,将该值设置为100,燎动窗口为10秒, 若在10秒内一 一个“桶 ” 中发生7500次执行,
//那么该“桶”中只保留最后的100次执行的统计。另外,增加该值的大小将会增加内存量的消耗, 并增加排序百分位数所需的计算
@HystrixProperty(name = "metrics.rollingPercentile.bucketSize", value = "100"),
//该属性用来设置采集影响断路器状态的健康快照(请求的成功、错误百分比) 的间隔等待时间。
@HystrixProperty(name = "metrics.healthSnapshot.intervalinMilliseconds", value = "500"),
//是否开启请求缓存
@HystrixProperty(name = "requestCache.enabled", value = "true"),
// HystrixCommand的执行和时间是否打印日志到HystrixRequestLog中
@HystrixProperty(name = "requestLog.enabled", value = "true"),
},
threadPoolProperties = {
//该参数用来设置执行命令线程他的核心线程数,该值 也就是命令执行的最大并发量
@HystrixProperty(name = "coreSize", value = "10"),
//该参数用来设置线程她的最大队列大小。当设置为-1时,线程池将使用SynchronousQueue 实现的队列,
// 否则将使用LinkedBlocakingQueue实现队列
@HystrixProperty(name = "maxQueueSize", value = "-1"),
// 该参数用来为队列设置拒绝阀值。 通过该参数, 即使队列没有达到最大值也能拒绝请求。
//該参数主要是対linkedBlockingQueue 队列的朴充,因为linkedBlockingQueue
//队列不能动态修改它的对象大小,而通过该属性就可以调整拒绝请求的队列大小了。
@HystrixProperty(name = "queueSizeRejectionThreshold", value = "5"),
}
)
public String paymentCircuitBreakerAllConditionallback(@PathVariable("id") Integer id) {
return "id 不能负数,请稍后再试,o(╥﹏╥)o id:" + id;
}
}
PaymentController
package com.banana.springcloud.controller;
import com.banana.springcloud.service.PaymentService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
/**
* @author layman
* @date 2021/1/18
*/
@RestController
@Slf4j
@RequestMapping("/payment")
public class PaymentController {
@Resource
private PaymentService paymentService;
@Value("${server.port}")
private String serverPort;
/**
* 模拟正常访问
*/
@GetMapping("/hystrix/success/{id}")
public String paymentSuccess(@PathVariable("id")Integer id) {
String result = paymentService.paymentSuccess(id);
log.info("------result---------:"+result);
return result;
}
/**
* 模拟超时操作
*/
@GetMapping("/hystrix/timeout/{id}")
public String paymentTimeOut(@PathVariable("id")Integer id) {
String result = paymentService.paymentTimeOut(id);
log.info("------result---------:"+result);
return result;
}
/**
* 服务熔断
* @param id
* @return
*/
@GetMapping("/hystrix/circuit/{id}")
public String paymentCircuitBreaker(@PathVariable("id") Integer id) {
String result = paymentService.paymentCircuitBreaker(id);
log.info("------------result: " + result);
return result;
}
}