kafka ConsumerManager 源码

  • 2022-10-20
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kafka ConsumerManager 代码


 * 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,
 * See the License for the specific language governing permissions and
 * limitations under the License.
package org.apache.kafka.server.log.remote.metadata.storage;

import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.clients.producer.RecordMetadata;
import org.apache.kafka.common.KafkaException;
import org.apache.kafka.common.TopicIdPartition;
import org.apache.kafka.common.utils.KafkaThread;
import org.apache.kafka.common.utils.Time;
import org.apache.kafka.common.utils.Utils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Closeable;
import java.io.File;
import java.io.IOException;
import java.nio.file.Path;
import java.util.Optional;
import java.util.Set;
import java.util.concurrent.TimeoutException;

 * This class manages the consumer thread viz {@link ConsumerTask} that polls messages from the assigned metadata topic partitions.
 * It also provides a way to wait until the given record is received by the consumer before it is timed out with an interval of
 * {@link TopicBasedRemoteLogMetadataManagerConfig#consumeWaitMs()}.
public class ConsumerManager implements Closeable {

    public static final String COMMITTED_OFFSETS_FILE_NAME = "_rlmm_committed_offsets";

    private static final Logger log = LoggerFactory.getLogger(ConsumerManager.class);
    private static final long CONSUME_RECHECK_INTERVAL_MS = 50L;

    private final TopicBasedRemoteLogMetadataManagerConfig rlmmConfig;
    private final Time time;
    private final ConsumerTask consumerTask;
    private final Thread consumerTaskThread;

    public ConsumerManager(TopicBasedRemoteLogMetadataManagerConfig rlmmConfig,
                           RemotePartitionMetadataEventHandler remotePartitionMetadataEventHandler,
                           RemoteLogMetadataTopicPartitioner topicPartitioner,
                           Time time) {
        this.rlmmConfig = rlmmConfig;
        this.time = time;

        //Create a task to consume messages and submit the respective events to RemotePartitionMetadataEventHandler.
        KafkaConsumer<byte[], byte[]> consumer = new KafkaConsumer<>(rlmmConfig.consumerProperties());
        Path committedOffsetsPath = new File(rlmmConfig.logDir(), COMMITTED_OFFSETS_FILE_NAME).toPath();
        consumerTask = new ConsumerTask(consumer, remotePartitionMetadataEventHandler, topicPartitioner, committedOffsetsPath, time, 60_000L);
        consumerTaskThread = KafkaThread.nonDaemon("RLMMConsumerTask", consumerTask);

    public void startConsumerThread() {
        try {
            // Start a thread to continuously consume records from topic partitions.
            log.info("RLMM Consumer task thread is started");
        } catch (Exception e) {
            throw new KafkaException("Error encountered while initializing and scheduling ConsumerTask thread", e);

     * Waits if necessary for the consumption to reach the offset of the given {@code recordMetadata}.
     * @param recordMetadata record metadata to be checked for consumption.
     * @throws TimeoutException if this method execution did not complete with in the wait time configured with
     *                          property {@code TopicBasedRemoteLogMetadataManagerConfig#REMOTE_LOG_METADATA_CONSUME_WAIT_MS_PROP}.
    public void waitTillConsumptionCatchesUp(RecordMetadata recordMetadata) throws TimeoutException {
        waitTillConsumptionCatchesUp(recordMetadata, rlmmConfig.consumeWaitMs());

     * Waits if necessary for the consumption to reach the offset of the given {@code recordMetadata}.
     * @param recordMetadata record metadata to be checked for consumption.
     * @param timeoutMs      wait timeout in milli seconds
     * @throws TimeoutException if this method execution did not complete with in the given {@code timeoutMs}.
    public void waitTillConsumptionCatchesUp(RecordMetadata recordMetadata,
                                             long timeoutMs) throws TimeoutException {
        final int partition = recordMetadata.partition();
        final long consumeCheckIntervalMs = Math.min(CONSUME_RECHECK_INTERVAL_MS, timeoutMs);

        // If the current assignment does not have the subscription for this partition then return immediately.
        if (!consumerTask.isPartitionAssigned(partition)) {
            throw new KafkaException("This consumer is not subscribed to the target partition " + partition + " on which message is produced.");

        final long offset = recordMetadata.offset();
        long startTimeMs = time.milliseconds();
        while (true) {
            long receivedOffset = consumerTask.receivedOffsetForPartition(partition).orElse(-1L);
            if (receivedOffset >= offset) {

            log.debug("Committed offset [{}] for partition [{}], but the target offset: [{}],  Sleeping for [{}] to retry again",
                      offset, partition, receivedOffset, consumeCheckIntervalMs);

            if (time.milliseconds() - startTimeMs > timeoutMs) {
                log.warn("Committed offset for partition:[{}] is : [{}], but the target offset: [{}] ",
                         partition, receivedOffset, offset);
                throw new TimeoutException("Timed out in catching up with the expected offset by consumer.");


    public void close() throws IOException {
        // Consumer task will close the task and it internally closes all the resources including the consumer.
        Utils.closeQuietly(consumerTask, "ConsumerTask");

        // Wait until the consumer thread finishes.
        try {
        } catch (Exception e) {
            log.error("Encountered error while waiting for consumerTaskThread to finish.", e);

    public void addAssignmentsForPartitions(Set<TopicIdPartition> partitions) {

    public void removeAssignmentsForPartitions(Set<TopicIdPartition> partitions) {

    public Optional<Long> receivedOffsetForPartition(int metadataPartition) {
        return consumerTask.receivedOffsetForPartition(metadataPartition);


kafka 源码目录


kafka CommittedOffsetsFile 源码

kafka ConsumerTask 源码

kafka FileBasedRemoteLogMetadataCache 源码

kafka ProducerManager 源码

kafka RemoteLogLeaderEpochState 源码

kafka RemoteLogMetadataCache 源码

kafka RemoteLogMetadataSnapshotFile 源码

kafka RemoteLogMetadataTopicPartitioner 源码

kafka RemoteLogSegmentMetadataSnapshot 源码

kafka RemotePartitionMetadataEventHandler 源码

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