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.Public;
022    import org.apache.hadoop.classification.InterfaceStability.Unstable;
023    import org.apache.hadoop.yarn.api.protocolrecords.AllocateResponse;
024    
025    /**
026     * Command sent by the Resource Manager to the Application Master in the 
027     * AllocateResponse 
028     * @see AllocateResponse
029     */
030    @Public
031    @Unstable
032    public enum AMCommand {
033      /**
034       * Sent by Resource Manager when it is out of sync with the AM and wants the 
035       * AM get back in sync.
036       */
037      AM_RESYNC,
038      
039      /**
040       * Sent by Resource Manager when it wants the AM to shutdown. Eg. when the 
041       * node is going down for maintenance. The AM should save any state and 
042       * prepare to be restarted at a later time. 
043       */
044      AM_SHUTDOWN
045    }