springcloud整合Hystrix

作用

1、服务降级
触发情况：程序运行异常、超时、服务熔断触发服务降级、线程池/信号量打满也会触发服务降级
2、服务熔断
直接拒绝访问，即使有正确的访问也会短路
3、服务限流
排队有序进行

构建服务

1、建module
provider-hystrix-payment8001
2、改pom

<?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>cloud2020</artifactId>
        <groupId>com.atguigu.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-provider-hystrix-payment8001</artifactId>


    <dependencies>
        <!--新增hystrix-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        </dependency>


        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>

        <dependency>
            <groupId>com.atguigu.springcloud</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>${project.version}</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>

        <!--        <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>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

</project>

3、配yml

server:
  port: 8001

spring:
  application:
    name: cloud-provider-hystrix-payment

eureka:
  client:
    register-with-eureka: true
    fetch-registry: true
    service-url:
      #defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka
      defaultZone: http://eureka7001.com:7001/eureka

4、主启动

@SpringBootApplication
@EnableEurekaClient
//注解开启断路器功能
@EnableCircuitBreaker
public class CloudProviderHystrixPayment8001Application {
    public static void main(String[] args) {
        SpringApplication.run(CloudProviderHystrixPayment8001Application.class, args);
        System.out.println("启动成功");
    }
}

5、service

@Service
public class PaymentService {
    /**
     * 正常访问，肯定OK
     *
     * @param id
     * @return
     */
    public String paymentInfoOK(Integer id) {
        return "线程池:  " + Thread.currentThread().getName() + "  paymentInfoOK,id:  " + id + "\t"
                + "O(∩_∩)O哈哈~";
    }


    /**
     * 超时访问，设置自身调用超时的峰值，峰值内正常运行，超过了峰值需要服务降级 自动调用fallbackMethod 指定的方法
     * 超时异常或者运行异常 都会进行服务降级
     *
     * @param id
     * @return
     */
    @HystrixCommand(fallbackMethod = "paymentInfoTimeOutHandler", commandProperties = {
            @HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds", value = "5000")
    })
    public String paymentInfoTimeOut(Integer id) {
//        int age = 10/0;
        int second = 3;
        long start = System.currentTimeMillis();
        try {
            TimeUnit.SECONDS.sleep(second);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        long end = System.currentTimeMillis();
        System.out.println(end - start);
        return "线程池:  " + Thread.currentThread().getName() + " paymentInfoTimeOut,id:  " + id + "\t"
                + "O(∩_∩)O哈哈~" + "  耗时(秒): " + second;
    }
}

6、controller

@RestController
@RequestMapping("payment")
@Slf4j
public class PaymentController {
    /**
     * 服务对象
     */
    @Resource
    private PaymentService paymentService;

    @Value("${server.port}")
    private String serverPort;


    /**
     * 正常访问
     *
     * @param id
     * @return
     */
    @GetMapping("/hystrix/ok/{id}")
    public String paymentInfoOK(@PathVariable("id") Integer id) {
        String result = paymentService.paymentInfoOK(id);
        log.info("result: " + result);
        return result;
    }


    /**
     * 超时或者异常
     *
     * @param id
     * @return
     */
    @GetMapping("/hystrix/timeout/{id}")
    public String paymentInfoTimeOut(@PathVariable("id") Integer id) {
        String result = paymentService.paymentInfoTimeOut(id);
        log.info("result: " + result);
        return result;
    }
}

7、测试
正常访问：http://localhost:8001/payment/hystrix/ok/31
5s返回：http://localhost:8001/payment/hystrix/timeout/31

高并发测试

1、jmeter压力测试
开启Jmeter，来20000个并发压死8001，20000个请求都去访问paymentInfo_TimeOut服务
2、访问上面的测试地址发现两个地址都加载不出或者卡死：tomcat默认的工作线程满了，没有多余的线程来来处理访问
3、加入order服务来调用payment生产者接口
4、建module
cloud-consumer-hystrix-order80
5、改pom

<?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>cloud2020</artifactId>
        <groupId>com.atguigu.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-consumer-feign-hystrix-order80</artifactId>

    <dependencies>
        <!--新增hystrix-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>com.atguigu.springcloud</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>${project.version}</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>

        <!--        <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>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>


</project>

6、配yml

server:
  port: 80

eureka:
  client:
    register-with-eureka: false
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka/

7、主启动

@SpringBootApplication
@EnableFeignClients // 启动 feign
@EnableHystrix // 启动 hystrix
public class CloudConsumerFeignHystrixOrder80Application {

    public static void main(String[] args) {
        SpringApplication.run(CloudConsumerFeignHystrixOrder80Application.class, args);
        System.out.println("启动成功");

    }

}

8、service

@Component
// FeignFallback 客户端的服务降级 针对 CLOUD-PROVIDER-HYSTRIX-PAYMENT 该服务 提供了一个 对应的服务降级类
@FeignClient(value = "CLOUD-PROVIDER-HYSTRIX-PAYMENT", fallback = PaymentFallbackServiceImpl.class)
//@FeignClient(value = "CLOUD-PROVIDER-HYSTRIX-PAYMENT")
public interface PaymentHystrixService {
    @GetMapping("/payment/hystrix/ok/{id}")
    String paymentInfoOK(@PathVariable("id") Integer id);

    @GetMapping("/payment/hystrix/timeout/{id}")
    String paymentInfoTimeOut(@PathVariable("id") Integer id);
}

9、controller

@RestController
@RequestMapping("consumer")
@Slf4j
public class OrderHystrixController {
    @Resource
    private PaymentHystrixService paymentHystrixService;

    @GetMapping("/payment/hystrix/ok/{id}")
    public String paymentInfoOK(@PathVariable("id") Integer id) {
        String result = paymentHystrixService.paymentInfoOK(id);
        return result;
    }


    @GetMapping("/payment/hystrix/timeout/{id}")
//    @HystrixCommand(fallbackMethod = "paymentTimeOutFallbackMethod", commandProperties = {
//            @HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds", value = "5000")
//    })
    @HystrixCommand
    public String paymentInfoTimeOut(@PathVariable("id") Integer id) {
        int age = 10 / 0;
        String result = paymentHystrixService.paymentInfoTimeOut(id);
        return result;
    }
}

10、测试
http://localhost/consumer/payment/hystrix/ok/31
11、高并发测试
2w个线程压8001，发现order服务访问一直转圈，或者报超时错误
结论：我们需要有降级、熔断、限流等策略解决问题

8001服务端自身调用fallback

1、主启动修改
@EnableCircuitBreaker
2、接口注解添加

@HystrixCommand(fallbackMethod = "paymentInfoTimeOutHandler", commandProperties = {
            @HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds", value = "5000")
    })

3、添加fallback方法

    /**
     * paymentInfoTimeOut 方法失败后 自动调用此方法 实现服务降级 告知调用者 paymentInfoTimeOut 目前无法正常调用
     *
     * @param id
     * @return
     */
    public String paymentInfoTimeOutHandler(Integer id) {
        return "线程池:  " + Thread.currentThread().getName() + "  paymentInfoTimeOutHandler8001系统繁忙或者运行报错，请稍后再试,id:  " + id + "\t"
                + "o(╥﹏╥)o";
    }

4、测试

order80端fallback

1、修改yml

feign:
  hystrix:
    enabled: true #如果处理自身的容错就开启。开启方式与生产端不一样。

2、修改主启动
@EnableHystrix
3、业务类

@HystrixCommand(fallbackMethod = "paymentTimeOutFallbackMethod", commandProperties = {
            @HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds", value = "5000")

4、测试

问题

1、每个业务接口都需要有一个兜底的fallback方法，代码膨胀
2、统一的fallback方法如何和自定义的fallback方法分开

解决问题

1、 controller添加统一的fallback

@DefaultProperties(defaultFallback = "payment_Global_FallbackMethod")// hystrix 全局fallback方法

2、为接口方法进行统一的异常处理
PaymentFallbackService类实现PaymentFeignClientService接口

@Component
public class PaymentFallbackServiceImpl implements PaymentHystrixService {

    @Override
    public String paymentInfoOK(Integer id) {
        return "-----PaymentFallbackService fall back-paymentInfo_OK ,o(╥﹏╥)o";
    }

    @Override
    public String paymentInfoTimeOut(Integer id) {
        return "-----PaymentFallbackService fall back-paymentInfo_TimeOut ,o(╥﹏╥)o";
    }

}

3、修改yml

feign:
  hystrix:
    enabled: true #如果处理自身的容错就开启。开启方式与生产端不一样。

4、修改PaymentHystrixService接口，添加统一的fallback

@FeignClient(value = "CLOUD-PROVIDER-HYSTRIX-PAYMENT", fallback = PaymentFallbackServiceImpl.class)

5、测试
1、正常访问：http://localhost/consumer/payment/hystrix/ok/31
2、异常访问：关闭provider，访问降级

服务熔断

是什么

熔断机制是一种应对雪崩效应的微服务链路保护机制

实操

1、修改provider-hystrix-payment8001

   /**
     * 服务熔断 超时、异常、都会触发熔断
     * 1、默认是最近10秒内收到不小于10个请求，<br/>
     * 2、并且有60%是失败的<br/>
     * 3、就开启断路器<br/>
     * 4、开启后所有请求不再转发，降级逻辑自动切换为主逻辑，减小调用方的响应时间<br/>
     * 5、经过一段时间（时间窗口期，默认是5秒），断路器变为半开状态，会让其中一个请求进行转发。<br/>
     * &nbsp;&nbsp;5.1、如果成功，断路器会关闭，<br/>
     * &nbsp;&nbsp;5.2、若失败，继续开启。重复4和5<br/>
     *
     * @param id
     * @return
     */
    @HystrixCommand(fallbackMethod = "paymentCircuitBreakerFallback", commandProperties = {
            @HystrixProperty(name = "circuitBreaker.enabled", value = "true"),/* 是否开启断路器*/
            @HystrixProperty(name = "circuitBreaker.requestVolumeThreshold", value = "10"),// 请求次数
            @HystrixProperty(name = "circuitBreaker.sleepWindowInMilliseconds", value = "10000"), // 时间窗口期
            @HystrixProperty(name = "circuitBreaker.errorThresholdPercentage", value = "60"),// 失败率达到多少后跳闸
//            @HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds", value = "5000")// 超时处理
    })
    public String paymentCircuitBreaker(Integer id) {
        if (id < 0) {
            throw new RuntimeException("******id 不能负数");
        }
        //测试异常
//        int age = 10 / 0;
//        int second = 3;
//        try {
//            TimeUnit.SECONDS.sleep(second);
//        } catch (InterruptedException e) {
//            e.printStackTrace();
//        }


        String serialNumber = IdUtil.simpleUUID();
        return Thread.currentThread().getName() + "\t" + "调用成功，流水号: " + serialNumber;
    }


    /**
     * paymentCircuitBreaker 方法的 fallback，<br/>
     * 当断路器开启时，主逻辑熔断降级，该 fallback 方法就会替换原 paymentCircuitBreaker 方法，处理请求
     *
     * @param id
     * @return
     */
    public String paymentCircuitBreakerFallback(Integer id) {
        return Thread.currentThread().getName() + "\t" + "id 不能负数或超时或自身错误，请稍后再试，/(ㄒoㄒ)/~~   id: " + id;
    }

2、修改paymentController

/**
     * 服务熔断
     *
     * @param id
     * @return
     */
    @GetMapping("/circuit/{id}")
    public String paymentCircuitBreaker(@PathVariable("id") Integer id) {
        String result = paymentService.paymentCircuitBreaker(id);
        log.info("****result: " + result);
        return result;
    }

3、测试
正确：http://localhost:8001/payment/circuit/31
错误：http://localhost:8001/payment/circuit/-31
重点测试：多次错误,然后慢慢正确，发现刚开始不满足条件，就算是正确的访问地址也不能进行访问，需要慢慢的恢复链路

服务限流

后面总结sentinel再讲

HystrixDashboard

记录通过Hystrix链路访问的成功和失败数量的统计，图表等
1、建module
consumer-hystrix-dashboard9001
2、改pom

<?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>cloud2020</artifactId>
        <groupId>com.atguigu.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-consumer-hystrix-dashboard9001</artifactId>


    <dependencies>
        <!--新增hystrix dashboard-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

        <!--        <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>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

</project>

3、配置yml

server:
  port: 9001

4、主启动配置注解@EnableHystrixDashboard

@SpringBootApplication
@EnableHystrixDashboard
public class CloudConsumerHystrixDashboard9001Application {

    public static void main(String[] args) {
        SpringApplication.run(CloudConsumerHystrixDashboard9001Application.class, args);
        System.out.println("启动成功");

    }

}

5、所有Provider微服务提供类（8001/8002/8003）都需要监控依赖配置

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

6、启动服务访问
http://localhost:9001/hystrix

演示

1、修改provider-hystrix-payment8001
注意：新版本Hystrix需要在主启动类MainAppHystrix8001中指定监控路径

    /**
     * 注意：新版本Hystrix需要在主启动类中指定监控路径
     * 此配置是为了服务监控而配置，与服务容错本身无关，spring cloud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面的servlet就可以了
     *
     * @return ServletRegistrationBean
     */
    @Bean
    public ServletRegistrationBean getServlet() {
        HystrixMetricsStreamServlet streamServlet = new HystrixMetricsStreamServlet();
        ServletRegistrationBean registrationBean = new ServletRegistrationBean(streamServlet);

        // 一启动就加载
        registrationBean.setLoadOnStartup(1);
        // 添加url
        registrationBean.addUrlMappings("/hystrix.stream");
        // 设置名称
        registrationBean.setName("HystrixMetricsStreamServlet");
        return registrationBean;
    }

2、9001监控8001
在这里插入图片描述
监控地址：http://localhost:8001/hystrix.stream
3、测试地址
正确：http://localhost:8001/payment/circuit/31
错误：http://localhost:8001/payment/circuit/-31
查看dashboard