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    
019    package org.apache.hadoop.yarn.api.records;
020    
021    import org.apache.hadoop.classification.InterfaceAudience.Private;
022    import org.apache.hadoop.classification.InterfaceAudience.Public;
023    import org.apache.hadoop.classification.InterfaceStability.Stable;
024    import 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
033    public 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    }