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Matthias J. Sax commented on KAFKA-16382: ----------------------------------------- Thanks for clarifying. Seems I did not understand the ticket correclty. {quote} # We start Kafka, it process the input topic from scratch but "optimise" internally nulls. The output topic *still* contains mapped result. The delete message *never* reach the output topic.{quote} You are right that this does not sound correct. Seems you can reliable reproduce the issue, so it should hopefully not be too hard to find a fix. Thanks for reporting it. > Kafka Streams drop NULL values after reset > ------------------------------------------ > > Key: KAFKA-16382 > URL: https://issues.apache.org/jira/browse/KAFKA-16382 > Project: Kafka > Issue Type: Bug > Components: streams > Affects Versions: 3.6.1 > Reporter: Stanislav Spiridonov > Priority: Major > > Kafka Streams (KTable) drops null values after full reset. > See > [https://github.com/foal/Null-Issue/blob/main/src/main/java/NullProblemExample.java] > for sample topology > Step to reproduce (req NULL-IN, NULL-IN-AUX, NULL-OUT topics) > # Start example - 1st round > # Send to NULL-IN "A1:a" -> NULL-OUT "A1:anull" > # Send to NULL-IN-AUX "A1:b" -> NULL-OUT "A1:anull, A1:ab" > # Stop application > # Run kafka-streams-application-reset > {code:java} > call bin/windows/kafka-streams-application-reset --application-id > nullproblem-example^ > --input-topics "NULL-IN,NULL-IN-AUX"^ > --bootstrap-server "localhost:9092" > {code} > # Send to NULL-IN-AUX "A1:" -> NULL-OUT "A1:anull, A1:ab" - it is Ok (no app > running yet) > # Start example - 2nd round > # After initialization -> NULL-OUT *still contains* "A1:anull, A1:ab" > # Expected output "A1:anull, A1:ab, A1:" > The issue is NOT reproduced if application just restarted (skip step 5). > The issue is NOT reproduced if internal cache is disabled. -- This message was sent by Atlassian Jira (v8.20.10#820010)