[jira] [Created] (KAFKA-13499) Avoid restoring outdated records

["Matthias J. Sax (Jira)" <ji...@apache.org>]

Matthias J. Sax created KAFKA-13499:
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             Summary: Avoid restoring outdated records
                 Key: KAFKA-13499
                 URL: https://issues.apache.org/jira/browse/KAFKA-13499
             Project: Kafka
          Issue Type: Improvement
          Components: streams
            Reporter: Matthias J. Sax


Kafka Streams has the config `windowstore.changelog.additional.retention.ms` to allow for an increase retention time.

While an increase retention time can be useful, it can also lead to unnecessary restore cost, especially for stream-stream joins. Assume a stream-stream join with 1h window size and a grace period of 1h. For this case, we only need 2h of data to restore. If we lag, the `windowstore.changelog.additional.retention.ms` helps to prevent the broker from truncating data too early. However, if we don't lag and we need to restore, we restore everything from the changelog.

Instead of doing a seek-to-beginning, we could use the timestamp index to seek the first offset older than the 2h "window" of data that we need to restore, to avoid unnecessary work.



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