Joachim Hereth created SPARK-24067:
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Summary: Spark 2.3 Streaming Kafka 0.10 Consumer Can't Handle
Non-consecutive Offsets (i.e. Log Compaction)
Key: SPARK-24067
URL: https://issues.apache.org/jira/browse/SPARK-24067
Project: Spark
Issue Type: Bug
Components: DStreams
Affects Versions: 2.0.0
Reporter: Joachim Hereth
Assignee: Cody Koeninger
Fix For: 2.4.0
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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