快速开始demo

demo-统计20秒内，10个请求有70%超时，则熔断

import com.netflix.hystrix.*;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/hystrix")
public class HystrixDemoController {

    /**
     * 模拟超时场景
     * @return
     * @throws Exception
     */
    @GetMapping("/timeout")
    public String timeout() throws Exception{
        // 20秒内，10个请求有70%超时，则熔断
        // 模拟调用15个请求，按理说调用到第11个请求(接收10个请求后，统计出70%超时)的时候，应该熔断，返回fallback结果
        for(int i=0; i<15; i++ ) {
            // 执行command
            try {
                RemoteCallTimeoutService remoteCallTimeoutService = new RemoteCallTimeoutService();
                System.out.println(i+"-"+remoteCallTimeoutService.execute());
            } catch (Exception e) {
                System.out.println(i+"-"+e.getMessage());
                if(i == 5 || i == 10){
                    Thread.sleep(1000);
                    commandStatus();
                }
            }
        }
        return "done";
    }

    /**
     * 获取Hystrix的监控信息
     * @return
     */
    @GetMapping("/commandStatus")
    public String commandStatus(){
        HystrixCommandGroupKey groupKey = HystrixCommandGroupKey.Factory.asKey("DemoGroup");
        HystrixCommandKey commandKey = HystrixCommandKey.Factory.asKey("RemoteCallTimeout");
        HystrixCircuitBreaker breaker = HystrixCircuitBreaker.Factory.getInstance(commandKey);
        HystrixCommandMetrics metrics = HystrixCommandMetrics.getInstance(commandKey);
        System.out.println("commandStatus=========================start");
        System.out.println("breaker.isOpen()=" + breaker.isOpen());
        System.out.println("metrics.getCommandGroup()=" + metrics.getCommandGroup());
        System.out.println("metrics.getCommandKey()=" + metrics.getCommandKey());
        System.out.println("metrics.getProperties().circuitBreakerEnabled()=" + metrics.getProperties().circuitBreakerEnabled().get());
        System.out.println("metrics.getProperties().metricsRollingStatisticalWindowInMilliseconds())=" + metrics.getProperties().metricsRollingStatisticalWindowInMilliseconds().get());
        System.out.println("metrics.getProperties().circuitBreakerRequestVolumeThreshold()=" + metrics.getProperties().circuitBreakerRequestVolumeThreshold().get());
        System.out.println("metrics.getProperties().circuitBreakerErrorThresholdPercentage()=" + metrics.getProperties().circuitBreakerErrorThresholdPercentage().get());
        System.out.println("metrics.getProperties().executionTimeoutInMilliseconds()=" + metrics.getProperties().executionTimeoutInMilliseconds().get());
        //Retrieve a snapshot of total requests, error count and error percentage.
        System.out.println("metrics.getHealthCounts()=total requests, error count and error percentage " + metrics.getHealthCounts());
        System.out.println("commandStatus=========================end");
        return "done";
    }

    /**
     * 20秒内，10个请求有70%超时，则熔断
     */
    private class RemoteCallTimeoutService extends HystrixCommand<String>{
        protected RemoteCallTimeoutService() {
            //super(HystrixCommandGroupKey.Factory.asKey("DemoGroup"), 5000);
            super(Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey("DemoGroup"))
                    .andCommandKey(HystrixCommandKey.Factory.asKey("RemoteCallTimeout"))
                    .andCommandPropertiesDefaults(HystrixCommandProperties.defaultSetter()
                            .withCircuitBreakerEnabled(true)
                            .withMetricsRollingStatisticalWindowInMilliseconds(20000)   //统计最近20s内的数据
                            .withCircuitBreakerRequestVolumeThreshold(10)   //最少10个请求才开始计算是否熔断
                            .withCircuitBreakerErrorThresholdPercentage(70) //错误率70%则熔断
                            .withExecutionTimeoutInMilliseconds(1000)   //设置1秒超时
                    ));
        }
        @Override
        protected String run() throws Exception {
            // a real example would do work like a network call here
            Thread.sleep(1200); //模拟执行远程调用超时
            return "run return";
            //throw new Exception("invoke error"); //模拟执行远程调用抛异常
        }

        /*@Override
        protected String getFallback() {
            return "invoke fallback method";
        }*/
    }
}

• 执行超时场景/hystrix/timeout
• 输出结果如下：

• 调用每次都超时
• 在第6次的时候打印断路器状态，发现是未打开
• 在第11次的时候打印断路器状态，发现已打开

0-RemoteCallTimeout timed-out and no fallback available.
1-RemoteCallTimeout timed-out and no fallback available.
2-RemoteCallTimeout timed-out and no fallback available.
3-RemoteCallTimeout timed-out and no fallback available.
4-RemoteCallTimeout timed-out and no fallback available.
5-RemoteCallTimeout timed-out and no fallback available.
commandStatus=========================start
breaker.isOpen()=false
metrics.getCommandGroup()=DemoGroup
metrics.getCommandKey()=RemoteCallTimeout
metrics.getProperties().circuitBreakerEnabled()=true
metrics.getProperties().metricsRollingStatisticalWindowInMilliseconds())=20000
metrics.getProperties().circuitBreakerRequestVolumeThreshold()=10
metrics.getProperties().circuitBreakerErrorThresholdPercentage()=70
metrics.getProperties().executionTimeoutInMilliseconds()=1000
metrics.getHealthCounts()=total requests, error count and error percentage HealthCounts[6 / 6 : 100%]
commandStatus=========================end
6-RemoteCallTimeout timed-out and no fallback available.
7-RemoteCallTimeout timed-out and no fallback available.
8-RemoteCallTimeout timed-out and no fallback available.
9-RemoteCallTimeout timed-out and no fallback available.
10-RemoteCallTimeout timed-out and no fallback available.
commandStatus=========================start
breaker.isOpen()=true
metrics.getCommandGroup()=DemoGroup
metrics.getCommandKey()=RemoteCallTimeout
metrics.getProperties().circuitBreakerEnabled()=true
metrics.getProperties().metricsRollingStatisticalWindowInMilliseconds())=20000
metrics.getProperties().circuitBreakerRequestVolumeThreshold()=10
metrics.getProperties().circuitBreakerErrorThresholdPercentage()=70
metrics.getProperties().executionTimeoutInMilliseconds()=1000
metrics.getHealthCounts()=total requests, error count and error percentage HealthCounts[11 / 11 : 100%]
commandStatus=========================end
11-RemoteCallTimeout short-circuited and no fallback available.
12-RemoteCallTimeout short-circuited and no fallback available.
13-RemoteCallTimeout short-circuited and no fallback available.
14-RemoteCallTimeout short-circuited and no fallback available.