kafka __consumer_offsets 主题的分区数过多

Question

我正在使用 Kafka 0.8.2，但我的消费者提示 "offset commit failed with ..." 时出现错误。在查看主题“__consumer_offsets”时。我看到它有 50 个分区数。那是正常的吗？我只能通过删除所有 Kafka 日志并重新启动我的 Kafka 服务器来解决这个问题。有没有办法在达到一定数量的分区时删除此主题，或者我是否提交了错误的偏移量？

这是我提交偏移量的方式：

 public void commitOffsets(BlockingChannel channel, String topic, String    groupid, int partition, String clientName, int corrilationid, long offset)   throws Exception{

    if (commitTryCount > 100){
        throw new Exception("Offset commit failed with " + channel.host());
    }

    long now = System.currentTimeMillis();
    Map<TopicAndPartition, OffsetAndMetadata> offsets = new LinkedHashMap<TopicAndPartition, OffsetAndMetadata>();
    //for (int i = 0; i < this.totalPartitions; i++){
        TopicAndPartition topicPartition = new TopicAndPartition(topic, partition);
        offsets.put(topicPartition, new OffsetAndMetadata(offset, topic, now));
    //}     

    //initialize offset commit
    OffsetCommitRequest commitRequest = new OffsetCommitRequest(groupid, offsets, corrilationid, clientName, (short) 1);
    channel.send(commitRequest.underlying());
    OffsetCommitResponse commitResponse = OffsetCommitResponse.readFrom(channel.receive().buffer());
    if (commitResponse.hasError()){         
        for (Object partitionErrorCode: commitResponse.errors().values()){
            if (Short.parseShort(partitionErrorCode.toString()) == ErrorMapping.OffsetMetadataTooLargeCode()){
                //reduce the size of the metadata and retry
                offset--;
                commitOffsets(channel, topic, groupid, partition, clientName, corrilationid, offset);
                commitTryCount++;
            } else if (Short.parseShort(partitionErrorCode.toString()) == ErrorMapping.NotCoordinatorForConsumerCode()
                    || Short.parseShort(partitionErrorCode.toString()) == ErrorMapping.ConsumerCoordinatorNotAvailableCode()) {
                //discover new coordinator and retry
                int newCorrilation = corrilationid;
                newCorrilation++;
                this.channel = discoverChannel(channel.host(), port, groupid, clientName, newCorrilation);
                commitOffsets(this.channel, topic, groupid, partition, clientName, newCorrilation, offset);
                commitTryCount++;
            } else{
                //retry
                commitOffsets(channel, topic, groupid, partition, clientName, corrilationid, offset);
                commitTryCount++;
            }//end of else              
        }//end of for
    }//end of if
}//end of method

Answer 1

我发布代码后就明白了。我忘记在提交成功时将变量 "commitTryCount" 设置为 0。我还在想 __consumer_offsets 主题有 50 个分区是否正常？

Answer 2

是的，默认 50 个消费者偏移分区。要更改，请设置 offsets.topic.num.partitions 属性.

kafka __consumer_offsets 主题的分区数过多

kafka __consumer_offsets topic has excessive partition count

apache-kafka

kafka-consumer-api