001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019package org.apache.hadoop.yarn.api.records;
020
021import org.apache.hadoop.classification.InterfaceAudience.Private;
022import org.apache.hadoop.classification.InterfaceAudience.Public;
023import org.apache.hadoop.classification.InterfaceStability.Stable;
024import org.apache.hadoop.classification.InterfaceStability.Unstable;
025
026/**
027 * <p><code>YarnClusterMetrics</code> represents cluster metrics.</p>
028 * 
029 * <p>Currently only number of <code>NodeManager</code>s is provided.</p>
030 */
031@Public
032@Stable
033public interface YarnClusterMetrics {
034  
035  /**
036   * Get the number of <code>NodeManager</code>s in the cluster.
037   * @return number of <code>NodeManager</code>s in the cluster
038   */
039  @Public
040  @Stable
041  public abstract int getNumNodeManagers();
042
043  @Private
044  @Unstable
045  public abstract void setNumNodeManagers(int numNodeManagers);
046
047}