开启四个事件处理队列：
private[scheduler] val SHARED_QUEUE = "shared"
private[scheduler] val APP_STATUS_QUEUE = "appStatus"
private[scheduler] val EXECUTOR_MANAGEMENT_QUEUE = "executorManagement"
private[scheduler] val EVENT_LOG_QUEUE = "eventLog"
每个队列单独一个线程处理。
转载于:https://www.jianshu.com/p/3449efbe7711