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;
020
021import org.apache.hadoop.classification.InterfaceAudience.Public;
022import org.apache.hadoop.classification.InterfaceStability.Stable;
023import org.apache.hadoop.yarn.api.protocolrecords.AllocateRequest;
024import org.apache.hadoop.yarn.api.protocolrecords.AllocateResponse;
025import org.apache.hadoop.yarn.api.protocolrecords.FinishApplicationMasterRequest;
026import org.apache.hadoop.yarn.api.protocolrecords.FinishApplicationMasterResponse;
027import org.apache.hadoop.yarn.api.protocolrecords.RegisterApplicationMasterRequest;
028import org.apache.hadoop.yarn.api.protocolrecords.RegisterApplicationMasterResponse;
029import org.apache.hadoop.yarn.api.records.Container;
030import org.apache.hadoop.yarn.api.records.ResourceRequest;
031import org.apache.hadoop.yarn.exceptions.YarnRemoteException;
032
033/**
034 * <p>The protocol between a live instance of <code>ApplicationMaster</code> 
035 * and the <code>ResourceManager</code>.</p>
036 * 
037 * <p>This is used by the <code>ApplicationMaster</code> to register/unregister
038 * and to request and obtain resources in the cluster from the
039 * <code>ResourceManager</code>.</p>
040 */
041@Public
042@Stable
043public interface AMRMProtocol {
044  
045  /**
046   * <p>The interface used by a new <code>ApplicationMaster</code> to register 
047   * with the <code>ResourceManager</code>.</p> 
048   * 
049   * <p>The <code>ApplicationMaster</code> needs to provide details such
050   * as RPC Port, HTTP tracking url etc. as specified in 
051   * {@link RegisterApplicationMasterRequest}.</p>
052   * 
053   * <p>The <code>ResourceManager</code> responds with critical details such 
054   * as minimum and maximum resource capabilities in the cluster as specified in
055   * {@link RegisterApplicationMasterResponse}.</p>
056   *  
057   * @param request registration request
058   * @return registration respose
059   * @throws YarnRemoteException
060   */
061  public RegisterApplicationMasterResponse registerApplicationMaster(
062      RegisterApplicationMasterRequest request) 
063  throws YarnRemoteException;
064  
065  /**
066   * <p>The interface used by an <code>ApplicationMaster</code> to notify the 
067   * <code>ResourceManager</code> about its completion (success or failed).</p>
068   * 
069   * <p>The <code>ApplicationMaster</code> has to provide details such as 
070   * final state, diagnostics (in case of failures) etc. as specified in 
071   * {@link FinishApplicationMasterRequest}.</p>
072   * 
073   * <p>The <code>ResourceManager</code> responds with 
074   * {@link FinishApplicationMasterResponse}.</p>
075   * 
076   * @param request completion request
077   * @return completion response
078   * @throws YarnRemoteException
079   */
080  public FinishApplicationMasterResponse finishApplicationMaster(
081      FinishApplicationMasterRequest request) 
082  throws YarnRemoteException;
083  
084  /**
085   * <p>The main interface between an <code>ApplicationMaster</code> 
086   * and the <code>ResourceManager</code>.</p>
087   * 
088   * <p>The <code>ApplicationMaster</code> uses this interface to provide a list  
089   * of {@link ResourceRequest} and returns unused {@link Container} allocated 
090   * to it via {@link AllocateRequest}.</p>
091   * 
092   * <p>This also doubles up as a <em>heartbeat</em> to let the 
093   * <code>ResourceManager</code> know that the <code>ApplicationMaster</code>
094   * is alive. Thus, applications should periodically make this call to be kept
095   * alive. The frequency depends on ??</p>
096   * 
097   * <p>The <code>ResourceManager</code> responds with list of allocated 
098   * {@link Container}, status of completed containers and headroom information 
099   * for the application.</p> 
100   * 
101   * <p>The <code>ApplicationMaster</code> can use the available headroom 
102   * (resources) to decide how to utilized allocated resources and make 
103   * informed decisions about future resource requests.</p>
104   * 
105   * @param request allocation request
106   * @return allocation response
107   * @throws YarnRemoteException
108   */
109  public AllocateResponse allocate(AllocateRequest request) 
110  throws YarnRemoteException;
111}