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我的一项 samza 任务有一个令人费解的问题。除了一个分区上的消息外，它可以正常工作。我有 9 个关于该主题的分区。如果我发送 1000 条消息，我只会收到大约 890 条消息。

我已经检查了 kafka-console-consumer 的分区键，我知道我的 samza 作业不会处理这些分区键，并且控制台消费者确实看到了该消息，所以我知道它正在被写入主题，并且至少一个普通消费者可以看看就好了。

我在 samza 上启用了调试日志记录，并且有很多消息org.apache.samza.checkpoint.kafka.KafkaCheckpointManager说：

为 taskName Partition 4 添加检查点 Checkpoint [offsets={SystemStreamPartition [kafka, com.mycompany.indexing.document, 4]=448}]

分区 4 总是显示 448。分区 0 有类似的日志，但在显示 448 的地方，它是一个稳定增长的数字。

我很乐意分享任何有趣的配置信息来帮助缩小范围，但现在，我对我什至会分享什么感到有点迷惑。

我正在运行ThreadJobFactory：

  • samza-kafka_2.10 版本 0.9.1

  • 客户端上的kafka_2.10版本0.8.2.1

  • 卡夫卡经纪人 0.9.0.0

更新

我使用相同的分区键查看了上游 samza 作业，发现上游分区 4 存在问题。使用 kafkacat 检查 samza 检查点主题，我看到分区 4 的检查点没有推进。首先我看到：

{"SystemStreamPartition [kafka, resource.mutation, 6]":{"system":"kafka","partition":"6","offset":"96639","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 3]":{"system":"kafka","partition":"3","offset":"47135","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 0]":{"system":"kafka","partition":"0","offset":"49476","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 4]":{"system":"kafka","partition":"4","offset":"2556","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 8]":{"system":"kafka","partition":"8","offset":"62263","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 1]":{"system":"kafka","partition":"1","offset":"52151","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 7]":{"system":"kafka","partition":"7","offset":"58081","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 5]":{"system":"kafka","partition":"5","offset":"47712","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 2]":{"system":"kafka","partition":"2","offset":"45831","stream":"resource.mutation"}}
% Reached end of topic __samza_checkpoint_ver_1_for_resource-normalizer_1 [0] at offset 81713

然后一分钟后我看到：

{"SystemStreamPartition [kafka, resource.mutation, 6]":{"system":"kafka","partition":"6","offset":"96624","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 3]":{"system":"kafka","partition":"3","offset":"47115","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 0]":{"system":"kafka","partition":"0","offset":"49462","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 4]":{"system":"kafka","partition":"4","offset":"2556","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 8]":{"system":"kafka","partition":"8","offset":"62252","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 1]":{"system":"kafka","partition":"1","offset":"52134","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 7]":{"system":"kafka","partition":"7","offset":"58063","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 5]":{"system":"kafka","partition":"5","offset":"47696","stream":"resource.mutation"}}
{"SystemStreamPartition [kafka, resource.mutation, 2]":{"system":"kafka","partition":"2","offset":"45817","stream":"resource.mutation"}}
% Reached end of topic __samza_checkpoint_ver_1_for_resource-normalizer_1 [0] at offset 81722

该数字没有超过 2556。但是，查看resource.mutation分区 4 上的实际主题，最后一个偏移量的范围与其他偏移量相似，截至目前约为 61000 并且还在增长。

根本没有错误消息或警告消息。它只是停止从分区 4 消费。

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1 回答 1

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问题是有一条消息超出max.message.bytes了 kafka 消费者的默认值。但是，负责使用该分区的线程不会给出任何类型的错误消息，而是简单地挂在该消息上。其他分区线程将愉快地继续进行。

一旦我们配置systems.kafka.consumer.fetch.message.max.bytes到足够大的值来消耗分区上的每条消息并重新启动作业，它就会从中断的地方继续工作，一切都按预期开始工作。

于 2016-04-29T21:27:53.593 回答