murblanc commented on a change in pull request #1684: URL: https://github.com/apache/lucene-solr/pull/1684#discussion_r468403391
########## File path: solr/core/src/java/org/apache/solr/cluster/placement/PlacementPlanFactory.java ########## @@ -0,0 +1,52 @@ +/* + * 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; + +import java.util.Set; + +/** + * Allows plugins to create {@link PlacementPlan}s telling the Solr layer where to create replicas following the processing of + * a {@link PlacementRequest}. The Solr layer can (and will) check that the {@link PlacementPlan} conforms to the {@link PlacementRequest} (and + * if it does not, the requested operation will fail). + */ +public interface PlacementPlanFactory { + /** + * <p>Creates a {@link PlacementPlan} for adding a new collection and its replicas. + * + * <p>This is in support of {@link org.apache.solr.cloud.api.collections.CreateCollectionCmd}. + */ + PlacementPlan createPlacementPlanNewCollection(CreateNewCollectionPlacementRequest request, String CollectionName, Set<ReplicaPlacement> replicaPlacements); + + /** + * <p>Creates a {@link PlacementPlan} for adding replicas to a given shard of an existing collection. + * + * <p>This is in support (directly or indirectly) of {@link org.apache.solr.cloud.api.collections.AddReplicaCmd}, + * {@link org.apache.solr.cloud.api.collections.CreateShardCmd}, {@link org.apache.solr.cloud.api.collections.ReplaceNodeCmd}, + * {@link org.apache.solr.cloud.api.collections.MoveReplicaCmd}, {@link org.apache.solr.cloud.api.collections.SplitShardCmd}, + * {@link org.apache.solr.cloud.api.collections.RestoreCmd} and {@link org.apache.solr.cloud.api.collections.MigrateCmd}. + * (as well as of {@link org.apache.solr.cloud.api.collections.CreateCollectionCmd} in the specific case of + * {@link org.apache.solr.common.params.CollectionAdminParams#WITH_COLLECTION} but this should be removed shortly and + * the section in parentheses of this comment should be removed when the {@code withCollection} javadoc link appears broken). + */ + PlacementPlan createPlacementPlanAddReplicas(AddReplicasPlacementRequest request, String CollectionName, Set<ReplicaPlacement> replicaPlacements); Review comment: That was my initial intention but then I switched to the factory approach. We can expose all accessors in PlacementPlan and let the plug-in build instances of it as it wishes. Maybe we should expose all accessors anyway, but I thought rather than letting each plug-in implement these interfaces again it's simpler to provide a factory. Also I saw no real added value from the plug-in perspective to have its own instance type. A provided factory allows to introduce constraints on acceptable parameters in a programmer friendly way (what a method accepts, different method names), if Solr side accepts any instance it would have to do some checks at runtime. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For additional commands, e-mail: issues-h...@lucene.apache.org
