[ https://issues.apache.org/jira/browse/KAFKA-6607?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Matthias J. Sax updated KAFKA-6607: ----------------------------------- Description: When an input topic for a Consumer or Kafka Streams application is written using transaction, the client does not commit "endOffset" but "endOffset - 1" if it reaches the end of topic. The reason is the commit marker that is the last "message" in the topic; Streams commit "offset of last processed message plus 1" and does not take commit markers into account. This is not a correctness issue, but when one inspect the consumer lag via {{bin/kafka-consumer.group.sh}} the lag is show as 1 instead of 0 – what is correct from consumer-group tool point of view. was: When an input topic for a Kafka Streams application is written using transaction, Kafka Streams does not commit "endOffset" but "endOffset - 1" if it reaches the end of topic. The reason is the commit marker that is the last "message" in the topic; Streams commit "offset of last processed message plus 1" and does not take commit markers into account. This is not a correctness issue, but when one inspect the consumer lag via {{bin/kafka-consumer.group.sh}} the lag is show as 1 instead of 0 – what is correct from consumer-group tool point of view. > Consumer Client and Kafka Streams lag not zero when input topic transactional > ----------------------------------------------------------------------------- > > Key: KAFKA-6607 > URL: https://issues.apache.org/jira/browse/KAFKA-6607 > Project: Kafka > Issue Type: Improvement > Components: clients, streams > Affects Versions: 1.0.0 > Reporter: Matthias J. Sax > Priority: Minor > > When an input topic for a Consumer or Kafka Streams application is written > using transaction, the client does not commit "endOffset" but "endOffset - 1" > if it reaches the end of topic. The reason is the commit marker that is the > last "message" in the topic; Streams commit "offset of last processed message > plus 1" and does not take commit markers into account. > This is not a correctness issue, but when one inspect the consumer lag via > {{bin/kafka-consumer.group.sh}} the lag is show as 1 instead of 0 – what is > correct from consumer-group tool point of view. -- This message was sent by Atlassian Jira (v8.3.4#803005)