solr/core/src/java/org/apache/solr/cluster/placement/impl/PlacementPluginAssignStrategy.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.solr.cluster.placement.impl;

import java.io.IOException;
import java.util.List;
import java.util.Set;

import org.apache.solr.client.solrj.cloud.SolrCloudManager;
import org.apache.solr.cloud.api.collections.Assign;
import org.apache.solr.cluster.SolrCollection;
import org.apache.solr.cluster.placement.DeleteCollectionRequest;
import org.apache.solr.cluster.placement.DeleteReplicasRequest;
import org.apache.solr.cluster.placement.PlacementContext;
import org.apache.solr.cluster.placement.PlacementException;
import org.apache.solr.cluster.placement.PlacementPlugin;
import org.apache.solr.cluster.placement.PlacementPlan;
import org.apache.solr.common.cloud.DocCollection;
import org.apache.solr.common.cloud.Replica;
import org.apache.solr.common.cloud.ReplicaPosition;

/**
 * This assign strategy delegates placement computation to "plugin" code.
 */
public class PlacementPluginAssignStrategy implements Assign.AssignStrategy {

  private final PlacementPlugin plugin;
  private final DocCollection collection;

  /**
   * @param collection the collection for which this assign request is done. In theory would be better to pass it into the
   *                   {@link #assign} call below (which would allow reusing instances of {@link PlacementPluginAssignStrategy},
   *                   but for now doing it here in order not to change the other Assign.AssignStrategy implementations.
   */
  public PlacementPluginAssignStrategy(DocCollection collection, PlacementPlugin plugin) {
    this.collection = collection;
    this.plugin = plugin;
  }

  public List<ReplicaPosition> assign(SolrCloudManager solrCloudManager, Assign.AssignRequest assignRequest)
      throws Assign.AssignmentException, IOException, InterruptedException {

    PlacementContext placementContext = new SimplePlacementContextImpl(solrCloudManager);
    SolrCollection solrCollection = placementContext.getCluster().getCollection(collection.getName());

    PlacementRequestImpl placementRequest = PlacementRequestImpl.toPlacementRequest(placementContext.getCluster(), solrCollection, assignRequest);

    final PlacementPlan placementPlan;
    try {
      placementPlan = plugin.computePlacement(placementRequest, placementContext);
    } catch (PlacementException pe) {
      throw new Assign.AssignmentException(pe);
    }

    return ReplicaPlacementImpl.toReplicaPositions(placementPlan.getReplicaPlacements());
  }

  @Override
  public void verifyDeleteCollection(SolrCloudManager solrCloudManager, DocCollection collection) throws Assign.AssignmentException, IOException, InterruptedException {
    PlacementContext placementContext = new SimplePlacementContextImpl(solrCloudManager);
    DeleteCollectionRequest modificationRequest = ModificationRequestImpl.createDeleteCollectionRequest(collection);
    try {
      plugin.verifyAllowedModification(modificationRequest, placementContext);
    } catch (PlacementException pe) {
      throw new Assign.AssignmentException(pe);
    }
  }

  @Override
  public void verifyDeleteReplicas(SolrCloudManager solrCloudManager, DocCollection collection, String shardId, Set<Replica> replicas) throws Assign.AssignmentException, IOException, InterruptedException {
    PlacementContext placementContext = new SimplePlacementContextImpl(solrCloudManager);
    DeleteReplicasRequest modificationRequest = ModificationRequestImpl.createDeleteReplicasRequest(collection, shardId, replicas);
    try {
      plugin.verifyAllowedModification(modificationRequest, placementContext);
    } catch (PlacementException pe) {
      throw new Assign.AssignmentException(pe);
    }
  }
}