hystrix_circuit_bug.java

package hystrix;

import com.netflix.hystrix.*;
import rx.Observable;

import java.io.IOException;
import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadPoolExecutor;

public class CommandHelloWorld extends HystrixCommand<String> {

    private String name;
    public int i;

    protected CommandHelloWorld(String name) {
        super(Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey("ThreadPoolTestGroup"))
                        .andCommandKey(HystrixCommandKey.Factory.asKey("testCommandKey"))
                        .andThreadPoolKey(HystrixThreadPoolKey.Factory.asKey(name))
                        .andCommandPropertiesDefaults(
                                HystrixCommandProperties.Setter()
                                        .withCircuitBreakerEnabled(true)//默认是true，本例中为了展现该参数
                                        .withCircuitBreakerForceOpen(false)//默认是false，本例中为了展现该参数
                                        .withCircuitBreakerForceClosed(false)//默认是false，本例中为了展现该参数
                                        .withCircuitBreakerErrorThresholdPercentage(10)//(1)错误百分比超过5%
                                        .withCircuitBreakerRequestVolumeThreshold(10)//(2)10s以内调用次数10次，同时满足(1)(2)熔断器打开
                                        .withCircuitBreakerSleepWindowInMilliseconds(999)//隔2s之后，熔断器会尝试半开(关闭)，重新放进来请求
//                                .withExecutionTimeoutInMilliseconds(1000)
                        )
                        .andThreadPoolPropertiesDefaults(
                                HystrixThreadPoolProperties.Setter()
                                        .withMaxQueueSize(60)   //配置队列大小
                                        .withCoreSize(2)    // 配置线程池里的线程数
                        )
        );
        this.name = name;
    }

    @Override
    protected String run() throws Exception {
        Random rand = new Random();
        //模拟错误百分比(方式比较粗鲁但可以证明问题)
        if (0 == rand.nextInt(2)) {
            throw new Exception("make exception");
        }
        return "ok";
    }

    @Override
    protected String getFallback() {
//        System.out.println("FAILBACK");
        return "fallback";
    }


    public static void main(String[] args) {
        int numThread = 50;
        ExecutorService exec = Executors.newFixedThreadPool(numThread);
        for (int t = 0; t < numThread; t++)
            exec.submit(new Runnable() {
                @Override
                public void run() {

                    for (int i = 0; i < 30; i++) {
                        CommandHelloWorld helloWorld = new CommandHelloWorld("LC");
                        try {
                            Thread.sleep(50);

                            String s = helloWorld.execute();
                            System.out.println(String.format("tid[%s] call times: %s, result: %s, circuitBreakerOpen: %s", Thread.currentThread().getName(), i, s, helloWorld.circuitBreaker.isOpen())
                            );

                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                }
            });

    }
}

0 == rand.nextInt(2)

这里有 50% 的概率失败，那就一直不能满足 1, 2 两个条件，所以 open 是正常的？