netty 监控线程池队列的运行情况

 /**
  * 依赖jar包    metrics-core-4.1.9.jar
  * 
　* NettyServer.exec 对象的定义 见   https://www.cnblogs.com/xiaodu9499/p/14328906.html
　*/

public class MetricsUtils {

    /**
     * 监控堆外内存使用情况
     * 工作线程的队列情况
     */
    public static void start() {
        // 注册
        MetricRegistry metricRegistry = new MetricRegistry();

        metricRegistry.register("已使用直接内存", (Gauge<Long>) () -> PlatformDependent.usedDirectMemory());

        metricRegistry.register("最大直接内存", (Gauge<Long>) () -> PlatformDependent.maxDirectMemory());

        for (EventExecutor eventExecutor : NettyServer.exec) {
            metricRegistry.register("exec=======等待队列大小"+eventExecutor.hashCode(), (Gauge<Integer>) () ->((SingleThreadEventExecutor)eventExecutor).pendingTasks());
        }

        // 打印到控制台
        ConsoleReporter consoleReporter = ConsoleReporter.forRegistry(metricRegistry).build();
        // 每5秒打印一次
        consoleReporter.start(5, TimeUnit.SECONDS);
    }

}