Github user HoustonPutman commented on a diff in the pull request: https://github.com/apache/lucene-solr/pull/313#discussion_r177865872 --- Diff: solr/solrj/src/java/org/apache/solr/common/cloud/CollectionSetWatcher.java --- @@ -0,0 +1,41 @@ +/* + * 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.common.cloud; + +import java.util.Set; + +/** + * Callback registered with {@link ZkStateReader#registerCollectionSetWatcher(CollectionSetWatcher)} + * and called whenever the cluster's collection set changes. + */ +public interface CollectionSetWatcher { + + /** + * Called when a collection is created, a collection is deleted or a watched collection's state changes. + * + * Note that, due to the way Zookeeper watchers are implemented, a single call may be + * the result of several collection set changes. Also, multiple calls to this method can be made + * with the same colllection set, ie. without any new updates. + * + * @param collections the set of collections + * + * @return true if the watcher should be removed --- End diff -- This follows the convention used in `CollectionStateWatcher`.
--- --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org