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    package org.apache.hadoop.yarn.api.records;
019    
020    import java.util.Set;
021    
022    import org.apache.hadoop.classification.InterfaceAudience.Private;
023    import org.apache.hadoop.classification.InterfaceAudience.Public;
024    import org.apache.hadoop.classification.InterfaceStability.Evolving;
025    import org.apache.hadoop.classification.InterfaceStability.Unstable;
026    import org.apache.hadoop.yarn.util.Records;
027    
028    /**
029     * Enumeration of particular allocations to be reclaimed. The platform will
030     * reclaim exactly these resources, so the <code>ApplicationMaster</code> (AM)
031     * may attempt to checkpoint work or adjust its execution plan to accommodate
032     * it. In contrast to {@link PreemptionContract}, the AM has no flexibility in
033     * selecting which resources to return to the cluster.
034     * @see PreemptionMessage
035     */
036    @Public
037    @Evolving
038    public abstract class StrictPreemptionContract {
039    
040      @Private
041      @Unstable
042      public static StrictPreemptionContract newInstance(Set<PreemptionContainer> containers) {
043        StrictPreemptionContract contract =
044            Records.newRecord(StrictPreemptionContract.class);
045        contract.setContainers(containers);
046        return contract;
047      }
048    
049      /**
050       * Get the set of {@link PreemptionContainer} specifying containers owned by
051       * the <code>ApplicationMaster</code> that may be reclaimed by the
052       * <code>ResourceManager</code>.
053       * @return the set of {@link ContainerId} to be preempted.
054       */
055      @Public
056      @Evolving
057      public abstract Set<PreemptionContainer> getContainers();
058    
059      @Private
060      @Unstable
061      public abstract void setContainers(Set<PreemptionContainer> containers);
062    
063    }