/**
 * 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.hadoop.yarn.server.federation.policies.manager;

import org.apache.commons.lang3.NotImplementedException;
import org.apache.hadoop.yarn.server.federation.policies.amrmproxy.BroadcastAMRMProxyPolicy;
import org.apache.hadoop.yarn.server.federation.policies.dao.WeightedPolicyInfo;
import org.apache.hadoop.yarn.server.federation.policies.router.UniformRandomRouterPolicy;

/**
 * This class represents a simple implementation of a {@code
 * FederationPolicyManager}.
 *
 * It combines the basic policies: {@link UniformRandomRouterPolicy} and
 * {@link BroadcastAMRMProxyPolicy}, which are designed to work together and
 * "spread" the load among sub-clusters uniformly.
 *
 * This simple policy might impose heavy load on the RMs and return more
 * containers than a job requested as all requests are (replicated and)
 * broadcasted.
 */
public class UniformBroadcastPolicyManager extends AbstractPolicyManager {

  public UniformBroadcastPolicyManager() {
    // this structurally hard-codes two compatible policies for Router and
    // AMRMProxy.
    routerFederationPolicy = UniformRandomRouterPolicy.class;
    amrmProxyFederationPolicy = BroadcastAMRMProxyPolicy.class;
  }

  @Override
  public WeightedPolicyInfo getWeightedPolicyInfo() {
    throw new NotImplementedException(
        "UniformBroadcastPolicyManager does not implement getWeightedPolicyInfo.");
  }

  @Override
  public void setWeightedPolicyInfo(WeightedPolicyInfo weightedPolicyInfo) {
    throw new NotImplementedException(
        "UniformBroadcastPolicyManager does not implement setWeightedPolicyInfo.");
  }

  @Override
  public boolean isSupportWeightedPolicyInfo() {
    return false;
  }
}
