[
https://issues.apache.org/jira/browse/KAFKA-4325?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16035688#comment-16035688
]
Jeyhun Karimov commented on KAFKA-4325:
---------------------------------------
[~mjsax], would this jira requre KIP?
> Improve processing of late records for window operations
> --------------------------------------------------------
>
> Key: KAFKA-4325
> URL: https://issues.apache.org/jira/browse/KAFKA-4325
> Project: Kafka
> Issue Type: Improvement
> Components: streams
> Reporter: Matthias J. Sax
> Priority: Minor
>
> Windows are kept until their retention time passed. If a late arriving record
> is processed that is older than any window kept, a new window is created
> containing this single late arriving record, the aggregation is computed and
> the window is immediately discarded afterward (as it is older than retention
> time).
> This behavior might case problems for downstream application as the original
> window aggregate might we overwritten with the late single-record- aggregate
> value. Thus, we should rather not process the late arriving record for this
> case.
> However, data loss might not be acceptable for all use cases. In order to
> enable the use to not lose any data, window operators should allow to
> register a handler function that is called instead of just dropping the late
> arriving record.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
