apoorvmittal10 commented on code in PR #18651: URL: https://github.com/apache/kafka/pull/18651#discussion_r1930867148
########## server/src/main/java/org/apache/kafka/server/share/fetch/PartitionRotateStrategy.java: ########## @@ -0,0 +1,106 @@ +/* + * 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.kafka.server.share.fetch; + +import org.apache.kafka.common.TopicIdPartition; + +import java.util.LinkedHashMap; +import java.util.Locale; +import java.util.Map; + +/** + * The PartitionRotateStrategy is used to rotate the partitions based on the respective strategy. + * The share-partitions are rotated to ensure no share-partitions are starved from records being fetched. + */ +public interface PartitionRotateStrategy { + + /** + * The strategy type to rotate the partitions. + */ + enum StrategyType { + ROUND_ROBIN; + + @Override + public String toString() { + return super.toString().toLowerCase(Locale.ROOT); + } + } + + /** + * Rotate the partitions based on the strategy. + * + * @param topicIdPartitions the topicIdPartitions to rotate + * @param metadata the metadata to rotate + * + * @return the rotated topicIdPartitions + */ + LinkedHashMap<TopicIdPartition, Integer> rotate(LinkedHashMap<TopicIdPartition, Integer> topicIdPartitions, PartitionRotateMetadata metadata); + + static PartitionRotateStrategy type(StrategyType type) { + return switch (type) { + case ROUND_ROBIN -> PartitionRotateStrategy::rotateRoundRobin; + }; + } + + /** + * Rotate the partitions based on the round-robin strategy. + * + * @param topicIdPartitions the topicIdPartitions to rotate + * @param metadata the metadata to rotate + * + * @return the rotated topicIdPartitions + */ + static LinkedHashMap<TopicIdPartition, Integer> rotateRoundRobin( + LinkedHashMap<TopicIdPartition, Integer> topicIdPartitions, + PartitionRotateMetadata metadata + ) { + if (topicIdPartitions.isEmpty() || topicIdPartitions.size() == 1 || metadata.sessionEpoch < 1) { + // No need to rotate the partitions if there are no partitions, only one partition or the + // session epoch is initial or final. + return topicIdPartitions; + } + + int rotateAt = metadata.sessionEpoch % topicIdPartitions.size(); + if (rotateAt == 0) { + // No need to rotate the partitions if the rotateAt is 0. + return topicIdPartitions; + } + + // Once the partition max bytes is removed then the partition will be a linked list and rotation Review Comment: Done. -- 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: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
