Map<NodePort, List<Integer>> keepAssigned =null;
if (!isScratch && allTaskIds!= null) {
//��ȡ���־����nodeport��task�ķ�����Ϣ
if (customAssignment != null) {
keepAssigned=customAssignment.keeperSlots(aliveAssigned, allTaskIds.size(),totalSlotsToUse);
}else{
keepAssigned = keeperSlots(aliveAssigned, allTaskIds.size(),totalSlotsToUse);// <NodePort, List>
}
}
//���·�����