murblanc commented on a change in pull request #1684: URL: https://github.com/apache/lucene-solr/pull/1684#discussion_r466721386
########## File path: solr/core/src/java/org/apache/solr/cluster/placement/AddReplicasRequest.java ########## @@ -0,0 +1,62 @@ +/* + * 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; + +/** + * <p>Request for creating one or more {@link Replica}'s for one or more {@link Shard}'s of an existing {@link SolrCollection}. + * The shard might or might not already exist, plugin code can easily find out by using {@link SolrCollection#getShards()} + * and verifying if the shard name(s) from {@link #getShardNames()} are there. + * + * <p>As opposed to {@link CreateNewCollectionRequest}, the set of {@link Node}s on which the replicas should be placed + * is specified (defaults to being equal to the set returned by {@link Cluster#getLiveNodes()}). + * + * <p>There is no extension between this interface and {@link CreateNewCollectionRequest} in either direction + * or from a common ancestor for readability. An ancestor could make sense and would be an "abstract interface" not intended + * to be implemented directly, but this does not exist in Java. + * + * <p>Plugin code would likely treat the two types of requests differently since here existing {@link Replica}'s must be taken + * into account for placement whereas in {@link CreateNewCollectionRequest} no {@link Replica}'s are assumed to exist. + */ +public interface AddReplicasRequest extends Request { + /** + * The {@link SolrCollection} to add {@link Replica}(s) to. The replicas are to be added to a shard that might or might + * not yet exist when the plugin's {@link PlacementPlugin#computePlacement} is called. + */ + SolrCollection getCollection(); + + /** + * <p>Shard name(s) for which new replicas placement should be computed. The shard(s) might exist or not (that's why this + * method returns a {@link Set} of {@link String}'s and not directly a set of {@link Shard} instances). + * + * <p>Note the Collection API allows specifying the shard name or a {@code _route_} parameter. The Solr implementation will + * convert either specification into the relevant shard name so the plugin code doesn't have to worry about this. + */ + Set<String> getShardNames(); + + /** Replicas should only be placed on nodes from the set returned by this method. */ + Set<Node> getTargetNodes(); Review comment: My motivation here was to not have the plugin worry about it and if no specific set of subnodes was passed, just make this set equivalent to all live nodes. That way no specific logic on the plugin side for dealing with this. ---------------------------------------------------------------- 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
