关于dubbo 自定义线程池的问题

spring.dubbo.protocol.threads = 2000
spring.dubbo.protocol.threadpool = cached
spring.dubbo.protocol.dispatcher = message

 <dubbo:protocol name="dubbo" threadpool="cached" dispatcher="message" threads="50" port="20880"/>

<dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.7.0</version>
        </dependency>

import org.apache.dubbo.common.URL;
import org.apache.dubbo.common.threadpool.support.fixed.FixedThreadPool;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Map;
import java.util.concurrent.*;

public class WatchingPool extends FixedThreadPool implements Runnable {

    private static final Logger LOGGER = LoggerFactory.getLogger(WatchingPool.class);

    // 线程池预警值【可以根据实际情况动态调整大小】
    private static final double ALARM_PERCENT = 0.70;

    private final Map<URL, ThreadPoolExecutor> theadPoolMap = new ConcurrentHashMap<>();

    public WatchingPool() {
        // 创建一个定时任务，每3秒执行一次【可以根据实际情况动态调整参数】
        Executors.newSingleThreadScheduledExecutor().scheduleWithFixedDelay(this, 1, 3, TimeUnit.SECONDS);
    }

    @Override
    public Executor getExecutor(URL url) {
        // 重写父类getExecutor, 如果executor是ThreadPoolExecutor，则放入theadPoolMap中
        Executor executor = super.getExecutor(url);
        if (executor instanceof ThreadPoolExecutor) {
            theadPoolMap.put(url, (ThreadPoolExecutor) executor);
        }

        return executor;

    public void run() {
        for (Map.Entry<URL, ThreadPoolExecutor> entry : theadPoolMap.entrySet()) {
            URL url = entry.getKey();
            ThreadPoolExecutor threadPoolExecutor = entry.getValue();
            // 获取正在活动的线程数
            int activeCount = threadPoolExecutor.getActiveCount();
            // 获取总的线程数  （继承的FixedThreadPool ， 所以这里获取核心的线程数就是总的线程数）
            int corePoolSize = threadPoolExecutor.getCorePoolSize();

            double percent = activeCount / (corePoolSize * 1.0);

            LOGGER.info("线程池状态：{}/{},: {}%", activeCount, corePoolSize, percent*100);
            if (percent > ALARM_PERCENT) {
                LOGGER.error("超出警戒线 : host:{}, 当前使用量 {}%, URL:{}", url.getHost(), percent*100, url);
            }

}

<dependency>
            <groupId>com.congge</groupId>
            <artifactId>common-pool</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

<dubbo:protocol name="dubbo" threadpool="watchingPool" threads="50" port="20880"/>

import com.congge.service.HelloService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.io.IOException;

public class ConsumerMain {
    public static void main(String[] args) throws Exception {

        ApplicationContext ac = new ClassPathXmlApplicationContext("spring-consumer.xml");
        HelloService service = (HelloService) ac.getBean("helloService");
        while (true){
            for(int i=0;i<1000;i++){
                Thread.sleep(6);
                new Thread( () ->{
                    String hello = service.hello("Hello Provider");
                    System.out.println(hello);
                }).start();
            }
        }
    }
}