@Override
  public void onRemove(LlapServiceInstance serviceInstance, int ephSeqVersion) {
    String workerIdentity = serviceInstance.getWorkerIdentity();
    llapClients.remove(workerIdentity);
    instanceStatisticsMap.remove(workerIdentity);
  }
Collect metrics from the llap daemons in every given milliseconds.
llap-tez/src/java/org/apache/hadoop/hive/llap/tezplugins/metrics/LlapMetricsCollector.java