[jira] [Comment Edited] (KAFKA-15417) JoinWindow does not seem to work properly with a KStream - KStream - LeftJoin()

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

    [ https://issues.apache.org/jira/browse/KAFKA-15417?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17761918#comment-17761918 ] 

Matthias J. Sax edited comment on KAFKA-15417 at 9/5/23 1:55 AM:
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I believe it could be related to an internal "throttling" mechanism that was added to improve throughput.

Can you try to set config `__{_}emit.interval.ms.kstreams.outer.join.spurious.results.fix{_}__` to zero to see if it resolves the issue?


was (Author: mjsax):
I believe it could be related to an internal "throttling" mechanism that was added to improve throughput.

Can you try to set config `__emit.interval.ms.kstreams.outer.join.spurious.results.fix__` to zero to see if it resolves the issue?

> JoinWindow does not  seem to work properly with a KStream - KStream - LeftJoin()
> --------------------------------------------------------------------------------
>
>                 Key: KAFKA-15417
>                 URL: https://issues.apache.org/jira/browse/KAFKA-15417
>             Project: Kafka
>          Issue Type: Bug
>          Components: streams
>    Affects Versions: 3.4.0
>            Reporter: Victor van den Hoven
>            Priority: Major
>         Attachments: SimpleStreamTopology.java, SimpleStreamTopologyTest.java
>
>
> In Kafka-streams 3.4.0 :
> According to the javadoc of the Joinwindow:
> _There are three different window configuration supported:_
>  * _before = after = time-difference_
>  * _before = 0 and after = time-difference_
>  * _*before = time-difference and after = 0*_
>  
> However if I use a joinWindow with *before = time-difference and after = 0* 
> on a kstream-kstream-leftjoin the *after=0* part does not seem to work.
> When using _stream1.leftjoin(stream2, joinWindow)_ with {_}joinWindow{_}.{_}after=0 and joinWindow.before=30s{_}, any new message on stream 1 that can not be joined with any messages on stream2 should be joined with a null-record after the _joinWindow.after_ has ended and a new message has arrived on stream1.
> It does not.
> Only if the new message arrives after the value of _joinWindow.before_ the previous message will be joined with a null-record.
>  
> Attached you can find two files with a TopologyTestDriver Unit test to reproduce.
> topology:   stream1.leftjoin( stream2, joiner, joinwindow)
> joinWindow has before=5000ms and after=0
> message1(key1) ->  stream1
> after 4000ms message2(key2) -> stream1  ->  NO null-record join was made, but the after period was expired.
> after 4900ms message2(key2) -> stream1  ->  NO null-record join was made, but the after period was expired.
> after 5000ms message2(key2) -> stream1  ->  A null-record join was made,  before period was expired.
> after 6000ms message2(key2) -> stream1  ->  A null-record join was made,  before period was expired.
>  



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