[jira] [Commented] (SPARK-17147) Spark Streaming Kafka 0.10 Consumer Can't Handle Non-consecutive Offsets (i.e. Log Compaction)

["chao.wu (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/SPARK-17147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16337027#comment-16337027 ] 

chao.wu commented on SPARK-17147:
---------------------------------

While the  topic clean config is delete "cleanup.policy=delete",  the offset  is also  non-consecutive. And it cause the spark streaming failure.
h1.  

> Spark Streaming Kafka 0.10 Consumer Can't Handle Non-consecutive Offsets (i.e. Log Compaction)
> ----------------------------------------------------------------------------------------------
>
>                 Key: SPARK-17147
>                 URL: https://issues.apache.org/jira/browse/SPARK-17147
>             Project: Spark
>          Issue Type: Bug
>          Components: DStreams
>    Affects Versions: 2.0.0
>            Reporter: Robert Conrad
>            Priority: Major
>
> When Kafka does log compaction offsets often end up with gaps, meaning the next requested offset will be frequently not be offset+1. The logic in KafkaRDD & CachedKafkaConsumer has a baked in assumption that the next offset will always be just an increment of 1 above the previous offset. 
> I have worked around this problem by changing CachedKafkaConsumer to use the returned record's offset, from:
> {{nextOffset = offset + 1}}
> to:
> {{nextOffset = record.offset + 1}}
> and changed KafkaRDD from:
> {{requestOffset += 1}}
> to:
> {{requestOffset = r.offset() + 1}}
> (I also had to change some assert logic in CachedKafkaConsumer).
> There's a strong possibility that I have misconstrued how to use the streaming kafka consumer, and I'm happy to close this out if that's the case. If, however, it is supposed to support non-consecutive offsets (e.g. due to log compaction) I am also happy to contribute a PR.



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