findingrish commented on code in PR #15817: URL: https://github.com/apache/druid/pull/15817#discussion_r1568601214
########## server/src/main/java/org/apache/druid/segment/metadata/SegmentSchemaManager.java: ########## @@ -0,0 +1,456 @@ +/* + * 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.druid.segment.metadata; + +import com.fasterxml.jackson.core.JsonProcessingException; +import com.fasterxml.jackson.databind.ObjectMapper; +import com.google.common.collect.Lists; +import com.google.common.collect.Sets; +import com.google.inject.Inject; +import org.apache.commons.lang.StringEscapeUtils; +import org.apache.druid.guice.LazySingleton; +import org.apache.druid.java.util.common.DateTimes; +import org.apache.druid.java.util.common.ISE; +import org.apache.druid.java.util.common.Pair; +import org.apache.druid.java.util.common.StringUtils; +import org.apache.druid.java.util.emitter.EmittingLogger; +import org.apache.druid.metadata.MetadataStorageTablesConfig; +import org.apache.druid.metadata.SQLMetadataConnector; +import org.apache.druid.segment.SchemaPayload; +import org.apache.druid.segment.SchemaPayloadPlus; +import org.apache.druid.timeline.SegmentId; +import org.skife.jdbi.v2.Handle; +import org.skife.jdbi.v2.PreparedBatch; +import org.skife.jdbi.v2.TransactionCallback; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.HashMap; +import java.util.HashSet; +import java.util.List; +import java.util.Map; +import java.util.Set; +import java.util.stream.Collectors; +import java.util.stream.IntStream; + +/** + * Handles segment schema persistence and cleanup. + */ +@LazySingleton +public class SegmentSchemaManager +{ + private static final EmittingLogger log = new EmittingLogger(SegmentSchemaManager.class); + private static final int DB_ACTION_PARTITION_SIZE = 100; + private final MetadataStorageTablesConfig dbTables; + private final ObjectMapper jsonMapper; + private final SQLMetadataConnector connector; + private final FingerprintGenerator fingerprintGenerator; + + @Inject + public SegmentSchemaManager( + MetadataStorageTablesConfig dbTables, + ObjectMapper jsonMapper, + SQLMetadataConnector connector, + FingerprintGenerator fingerprintGenerator + ) + { + this.dbTables = dbTables; + this.jsonMapper = jsonMapper; + this.connector = connector; + this.fingerprintGenerator = fingerprintGenerator; + } + + public List<Long> identifyReferencedUnusedSchema() + { + return connector.retryWithHandle( + handle -> + handle.createQuery( + StringUtils.format( + "SELECT DISTINCT(schema_id) FROM %s WHERE used = true AND schema_id IN (SELECT id FROM %s WHERE used = false)", Review Comment: The initial deletion logic didn't delete schema for unused segments, but in the latest refactor we changed that logic. Now we delete schema both unreferenced schema and schema referenced by unused segments. If a segment is marked as used at a later point, the backfill job will populate its schema. This would probably save us some memory on the Coordinator, as we don't have to store schema for unused segments. However, the downside is that we loose schema which might be required at a later point. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
