public void processConfigMessages(){
  List<String> keysToProcess=new LinkedList<>();
  keysToProcess.add(YARN_CONTAINER_COUNT_OPT);
  keysToProcess.add(SERVER_URL_OPT);
  processConfigMessages(keysToProcess);
}

public void processConfigMessages ( ) { List < String > keysToProcess = new LinkedList < > ( ) ; keysToProcess . add ( YARN_CONTAINER_COUNT_OPT ) ; keysToProcess . add ( SERVER_URL_OPT ) ; processConfigMessages ( keysToProcess ) ; }
this function reads all the messages with " set - config " type added to the coordinator stream since the last time the method was invoked
