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https://issues.apache.org/jira/browse/KAFKA-9572?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Guozhang Wang resolved KAFKA-9572.
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Fix Version/s: (was: 2.5.0)
2.6.0
Resolution: Fixed
> Sum Computation with Exactly-Once Enabled and Injected Failures Misses Some
> Records
> -----------------------------------------------------------------------------------
>
> Key: KAFKA-9572
> URL: https://issues.apache.org/jira/browse/KAFKA-9572
> Project: Kafka
> Issue Type: Bug
> Components: streams
> Affects Versions: 2.4.0
> Reporter: Bruno Cadonna
> Assignee: Guozhang Wang
> Priority: Blocker
> Fix For: 2.6.0
>
> Attachments: 7-changelog-1.txt, data-1.txt, streams22.log,
> streams23.log, streams30.log, sum-1.txt
>
>
> System test {{StreamsEosTest.test_failure_and_recovery}} failed due to a
> wrongly computed aggregation under exactly-once (EOS). The specific error is:
> {code:java}
> Exception in thread "main" java.lang.RuntimeException: Result verification
> failed for ConsumerRecord(topic = sum, partition = 1, leaderEpoch = 0, offset
> = 2805, CreateTime = 1580719595164, serialized key size = 4, serialized value
> size = 8, headers = RecordHeaders(headers = [], isReadOnly = false), key =
> [B@6c779568, value = [B@f381794) expected <6069,17269> but was <6069,10698>
> at
> org.apache.kafka.streams.tests.EosTestDriver.verifySum(EosTestDriver.java:444)
> at
> org.apache.kafka.streams.tests.EosTestDriver.verify(EosTestDriver.java:196)
> at
> org.apache.kafka.streams.tests.StreamsEosTest.main(StreamsEosTest.java:69)
> {code}
> That means, the sum computed by the Streams app seems to be wrong for key
> 6069. I checked the dumps of the log segments of the input topic partition
> (attached: data-1.txt) and indeed two input records are not considered in the
> sum. With those two missed records the sum would be correct. More concretely,
> the input values for key 6069 are:
> # 147
> # 9250
> # 5340
> # 1231
> # 1301
> The sum of this values is 17269 as stated in the exception above as expected
> sum. If you subtract values 3 and 4, i.e., 5340 and 1231 from 17269, you get
> 10698 , which is the actual sum in the exception above. Somehow those two
> values are missing.
> In the log dump of the output topic partition (attached: sum-1.txt), the sum
> is correct until the 4th value 1231 , i.e. 15968, then it is overwritten with
> 10698.
> In the log dump of the changelog topic of the state store that stores the sum
> (attached: 7-changelog-1.txt), the sum is also overwritten as in the output
> topic.
> I attached the logs of the three Streams instances involved.
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