NameNode的基于JMX的度量系统与JVM暂停监控

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spbreak

发布于 2024-05-05 14:56:19

780

发布于 2024-05-05 14:56:19

文章被收录于专栏：HDFSHDFS

MetricsSystem-度量系统-指标系统

用于记录NameNode指标值
基于JMX存储
通过HttpServer或JMX暴露对外

http访问方式: http://{namenodeIP}:{namenodePort}/jmx

JVMPauseMonitor

基于JMX存储
创建守护进程在后台运行
Runnable循环运行, 以sleep方式测量NameNode程序的反应时间, 反应时间超过阈值进行记录与统计

// 开启守护thread-(低优先级, 不阻塞thread运行, 随同thread消失而消失, 开启另一thread去守护thread)
  public class Daemon extends Thread {

  {
    setDaemon(true);                              // always a daemon
  }

// 核心循环任务-通过程序反应时间来测量是否暂停
  private class Monitor implements Runnable {
    @Override
    public void run() {
      // 时间统计工具
      Stopwatch sw = new Stopwatch();
      Map<String, GcTimes> gcTimesBeforeSleep = getGcTimes();
      while (shouldRun) {
        sw.reset().start();
        try {
          Thread.sleep(SLEEP_INTERVAL_MS);
        } catch (InterruptedException ie) {
          return;
        }
        long extraSleepTime = sw.elapsedMillis() - SLEEP_INTERVAL_MS;
        Map<String, GcTimes> gcTimesAfterSleep = getGcTimes();

        if (extraSleepTime > warnThresholdMs) {
          ++numGcWarnThresholdExceeded;
          LOG.warn(formatMessage(
              extraSleepTime, gcTimesAfterSleep, gcTimesBeforeSleep));
        } else if (extraSleepTime > infoThresholdMs) {
          ++numGcInfoThresholdExceeded;
          LOG.info(formatMessage(
              extraSleepTime, gcTimesAfterSleep, gcTimesBeforeSleep));
        }
        totalGcExtraSleepTime += extraSleepTime;
        gcTimesBeforeSleep = gcTimesAfterSleep;
      }
    }
  }