[KAFKA-5466] Unable to fetch elements from WindowStore when timestamp is before the first inserted Elem timestamp

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 0.10.2.1
• Component/s: streams
• Assignee: Unassigned
• Reporter: Jeetu Bethina
• Created: 18/Jun/17 15:17
• Updated: 18/Jun/17 15:19

Description

I am unable to fetch elements that are inserted with a timestamp before the timestamp of the first element inserted into a WindowStore.

This affects newly created WindowStores or one that is restored from a changelog topic.

The method I use to insert into the Window Store is

http://docs.confluent.io/3.2.1/streams/javadocs/org/apache/kafka/streams/state/WindowStore.html#put-K-V-long-

Looking into the code, the issue might be with how the minSegmentId is being calculated here.

https://github.com/apache/kafka/blob/trunk/streams/src/main/java/org/apache/kafka/streams/state/internals/Segments.java#L88

Something like the below fixes the issue with regards to the WindowStore but I am not sure what the implications would be for Streams as a whole.

if (minSegmentId == Long.MAX_VALUE) {
minSegmentId = maxSegmentId;
} else {
minSegmentId = segmentId < minSegmentId ? segmentId : minSegmentId;
}