vigyasharma commented on code in PR #15015: URL: https://github.com/apache/lucene/pull/15015#discussion_r2253329820
########## lucene/core/src/java/org/apache/lucene/index/MultiIndexMergeScheduler.java: ########## @@ -0,0 +1,203 @@ +/* + * 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.lucene.index; + +import java.io.IOException; +import org.apache.lucene.store.Directory; +import org.apache.lucene.util.InfoStream; + +class MultiIndexMergeScheduler extends MergeScheduler { + private final Directory directory; + private final CombinedMergeScheduler combinedMergeScheduler; + + /** The main MultiIndexMergeScheduler constructor -- use this one. */ + public MultiIndexMergeScheduler(Directory directory) { + this.directory = directory; + this.combinedMergeScheduler = CombinedMergeScheduler.singleton; + } + + /** Alternate MultiIndexMergeScheduler constructor for unit testing or tenant grouping. */ + public MultiIndexMergeScheduler( + Directory directory, CombinedMergeScheduler combinedMergeScheduler) { + this.directory = directory; + this.combinedMergeScheduler = combinedMergeScheduler; + } + + public Directory getDirectory() { + return directory; + } + + public CombinedMergeScheduler getCombinedMergeScheduler() { + return combinedMergeScheduler; + } + + @Override + public void merge(MergeSource mergeSource, MergeTrigger trigger) throws IOException { + var taggedMergeSource = + new CombinedMergeScheduler.TaggedMergeSource(mergeSource, this.directory); + this.combinedMergeScheduler.merge(taggedMergeSource, trigger); + } + + @Override + public Directory wrapForMerge(MergePolicy.OneMerge merge, Directory in) { + return this.combinedMergeScheduler.wrapForMerge(merge, in); + } + + /** Close this scheduler for one directory/index. Called automatically by IndexWriter. */ + @Override + public void close() throws IOException { + this.combinedMergeScheduler.close(this.directory); + } + + // We created this method because we cannot easily override the initialize() method + // in ConcurrentMergeScheduler. We don't need the initDynamicDefaults() part in the + // initialize() method, and only need the setInfoStream(). + public void setInfoStream(InfoStream infoStream) { + this.combinedMergeScheduler.setInfoStream(infoStream); + } + + /** + * CombinedMergeScheduler is used internally by MultiIndexMergeScheduler to balance resources + * across multiple indices. Normally you don't need to use this. + * + * <p>For testing purposes, or if partitioning of tenants into groups is needed for some reason, a + * CombinedMergeScheduler can be provided to the MultiIndexMergeScheduler constructor. + * + * <p>CombinedMergeScheduler should <b><i>not</i></b> be passed directly to IndexWriter. Review Comment: Setting max threads and merges is a common requirement, I think. We override it for the CMS in Amazon Search, and I suspect many other Lucene users do as well. Static setters don't fit well with CMS which is created per IW. Adding them to CombinedMS wouldn't work for users who setup index groups that share a CMS, by passing CombinedMS in the ctor. I think it is okay to let users directly work with public APIs for the underlying CMS. We can keep them informed via doc strings and mark the getter as a "expert" functionality. -- 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. To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org 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
