cadonna commented on a change in pull request #10163: URL: https://github.com/apache/kafka/pull/10163#discussion_r585544243
########## File path: streams/src/main/java/org/apache/kafka/streams/processor/internals/ChangelogTopics.java ########## @@ -0,0 +1,132 @@ +/* + * 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.streams.processor.internals; + +import org.apache.kafka.common.TopicPartition; +import org.apache.kafka.common.utils.LogContext; +import org.apache.kafka.streams.processor.TaskId; +import org.apache.kafka.streams.processor.internals.InternalTopologyBuilder.TopicsInfo; +import org.slf4j.Logger; + +import java.util.Collections; +import java.util.HashMap; +import java.util.HashSet; +import java.util.Map; +import java.util.Set; +import java.util.stream.Collectors; + +import static org.apache.kafka.streams.processor.internals.assignment.StreamsAssignmentProtocolVersions.UNKNOWN; + +public class ChangelogTopics { + + private final InternalTopicManager internalTopicManager; + private final Map<Integer, TopicsInfo> topicGroups; + private final Map<Integer, Set<TaskId>> tasksForTopicGroup; + private final Map<TaskId, Set<TopicPartition>> changelogPartitionsForTask = new HashMap<>(); + private final Map<TaskId, Set<TopicPartition>> preExistingChangelogPartitionsForTask = new HashMap<>(); + private final Set<TopicPartition> preExistingNonSourceTopicBasedChangelogPartitions = new HashSet<>(); + private final Set<String> sourceTopicBasedChangelogTopics = new HashSet<>(); + private final Set<TopicPartition> sourceTopicBasedChangelogTopicPartitions = new HashSet<>(); + private final Logger log; + + public ChangelogTopics(final InternalTopicManager internalTopicManager, + final Map<Integer, TopicsInfo> topicGroups, + final Map<Integer, Set<TaskId>> tasksForTopicGroup, + final String logPrefix) { + this.internalTopicManager = internalTopicManager; + this.topicGroups = topicGroups; + this.tasksForTopicGroup = tasksForTopicGroup; + final LogContext logContext = new LogContext(logPrefix); + log = logContext.logger(getClass()); + } + + public void setup() { + // add tasks to state change log topic subscribers + final Map<String, InternalTopicConfig> changelogTopicMetadata = new HashMap<>(); + for (final Map.Entry<Integer, TopicsInfo> entry : topicGroups.entrySet()) { + final int topicGroupId = entry.getKey(); + final TopicsInfo topicsInfo = entry.getValue(); + + final Set<TaskId> topicGroupTasks = tasksForTopicGroup.get(topicGroupId); + if (topicGroupTasks == null) { + log.debug("No tasks found for topic group {}", topicGroupId); + continue; + } else if (topicsInfo.stateChangelogTopics.isEmpty()) { + continue; + } + + for (final TaskId task : topicGroupTasks) { + final Set<TopicPartition> changelogTopicPartitions = topicsInfo.stateChangelogTopics + .keySet() + .stream() + .map(topic -> new TopicPartition(topic, task.partition)) + .collect(Collectors.toSet()); + changelogPartitionsForTask.put(task, changelogTopicPartitions); + } + + for (final InternalTopicConfig topicConfig : topicsInfo.nonSourceChangelogTopics()) { + // the expected number of partitions is the max value of TaskId.partition + 1 + int numPartitions = UNKNOWN; + for (final TaskId task : topicGroupTasks) { + if (numPartitions < task.partition + 1) { + numPartitions = task.partition + 1; + } + } + topicConfig.setNumberOfPartitions(numPartitions); + changelogTopicMetadata.put(topicConfig.name(), topicConfig); + } + sourceTopicBasedChangelogTopics.addAll(topicsInfo.sourceTopicChangelogs()); + } + + final Set<String> newlyCreatedChangelogTopics = internalTopicManager.makeReady(changelogTopicMetadata); + log.debug("Created state changelog topics {} from the parsed topology.", changelogTopicMetadata.values()); + + for (final Map.Entry<TaskId, Set<TopicPartition>> entry : changelogPartitionsForTask.entrySet()) { + final TaskId taskId = entry.getKey(); + final Set<TopicPartition> topicPartitions = entry.getValue(); + for (final TopicPartition topicPartition : topicPartitions) { + if (!newlyCreatedChangelogTopics.contains(topicPartition.topic())) { + preExistingChangelogPartitionsForTask.computeIfAbsent(taskId, task -> new HashSet<>()).add(topicPartition); + if (!sourceTopicBasedChangelogTopics.contains(topicPartition.topic())) { + preExistingNonSourceTopicBasedChangelogPartitions.add(topicPartition); + } else { + sourceTopicBasedChangelogTopicPartitions.add(topicPartition); Review comment: Also here, if a changelog is source based it has to be pre-existing, because the `InternalTopicManager` will not setup source topics. However, making this clearer in the name does not harm. ---------------------------------------------------------------- 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: [email protected]
