/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.hadoop.yarn.server.resourcemanager.scheduler;

import org.apache.hadoop.classification.InterfaceAudience.Private;
import org.apache.hadoop.classification.InterfaceStability.Unstable;
import org.apache.hadoop.yarn.api.records.Resource;

/**
 * Represents a YARN Cluster Node from the viewpoint of the scheduler.
 */
@Private
@Unstable
public abstract class SchedulerNode {

  /**
   * Get hostname.
   * @return hostname
   */
  public abstract String getHostName();
  
  /**
   * Get rackname.
   * @return rackname
   */
  public abstract String getRackName();
  
  /**
   * Get used resources on the node.
   * @return used resources on the node
   */
  public abstract Resource getUsedResource();

  /**
   * Get available resources on the node.
   * @return available resources on the node
   */
  public abstract Resource getAvailableResource();

  /**
   * Get number of active containers on the node.
   * @return number of active containers on the node
   */
  public abstract int getNumContainers();

}
