Bruno Cadonna created KAFKA-9572: ------------------------------------ Summary: 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 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. -- This message was sent by Atlassian Jira (v8.3.4#803005)