public void awake() {
    synchronized (wakeupSyncObject) {
      activeAwakeRequest = true;
      wakeupSyncObject.notify();
    }
  }
Should be called from another thread when we want scheduler to
make a run ASAP (for example, to process desired configs of SCHs).
The method is guaranteed to return quickly.
ambari-server/src/main/java/org/apache/ambari/server/actionmanager/ActionScheduler.java