slider-core/src/main/java/org/apache/slider/server/appmaster/state/ContainerReleaseSelector.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.slider.server.appmaster.state;

import java.util.List;

/**
 * Interface implemented by anything that must choose containers to release
 * 
 */
public interface ContainerReleaseSelector {

  /**
   * Given a list of candidate containers, return a sorted version of the priority
   * in which they should be released. 
   * @param candidates candidate list ... everything considered suitable
   * @return
   */
  List<RoleInstance> sortCandidates(int roleId,
      List<RoleInstance> candidates,
      int minimumToSelect);
}