murblanc commented on a change in pull request #1684: URL: https://github.com/apache/lucene-solr/pull/1684#discussion_r469452206
########## File path: solr/core/src/java/org/apache/solr/cluster/placement/Cluster.java ########## @@ -0,0 +1,53 @@ +/* + * 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.io.IOException; +import java.util.Optional; +import java.util.Set; + +/** + * <p>A representation of the (initial) cluster state, providing information on which nodes are part of the cluster and a way + * to get to more detailed info. + * + * <p>This instance can also be used as a {@link PropertyValueSource} if {@link PropertyKey}'s need to be specified with + * a global cluster target. + */ +public interface Cluster extends PropertyValueSource { + /** + * @return current set of live nodes. Never <code>null</code>, never empty (Solr wouldn't call the plugin if empty + * since no useful work could then be done). + */ + Set<Node> getLiveNodes(); + + /** + * <p>Returns info about the given collection if one exists. Because it is not expected for plugins to request info about + * a large number of collections, requests can only be made one by one. + * + * <p>This is also the reason we do not return a {@link java.util.Map} or {@link Set} of {@link SolrCollection}'s here: it would be + * wasteful to fetch all data and fill such a map when plugin code likely needs info about at most one or two collections. + */ + Optional<SolrCollection> getCollection(String collectionName) throws IOException; + + /** + * <p>Allows getting all {@link SolrCollection} present in the cluster. + * + * <p><b>WARNING:</b> this call might be extremely inefficient on large clusters. Usage is discouraged. + */ + Set<SolrCollection> getAllCollections(); Review comment: Ok. Can return names here. Still didn’t get what’s the use case for this method though. I’d assume if we need to fetch collection names we don’t know, we might want to fetch names that verify a given pattern. Maybe make this method accept some form of filtering? (Something that can be implemented efficiently if we ever want to, not an “accept” function that forces iterating over all collection names anyway). ---------------------------------------------------------------- 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
