[
https://issues.apache.org/jira/browse/FLINK-16193?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17041808#comment-17041808
]
Stephan Ewen commented on FLINK-16193:
--------------------------------------
There is a discussion as part of "unaligned checkpoints" whether we should
encode the key group in the stream element. Then it would be computed once (on
the sender) and used consistently from there.
The downside is that I believe you actually want failures when you have an
unstable key hashCode(), because it means that key grouping (for aggregates and
joins) will be wrong.
> Improve error messaging when a key is assigned to the wrong key group range
> ---------------------------------------------------------------------------
>
> Key: FLINK-16193
> URL: https://issues.apache.org/jira/browse/FLINK-16193
> Project: Flink
> Issue Type: Improvement
> Components: API / DataStream
> Affects Versions: 1.11.0
> Reporter: Seth Wiesman
> Assignee: Seth Wiesman
> Priority: Major
>
> Occasionally, users may run into an exception that reads something like:
>
> java.lang.IllegalArgumentException: Key group 45 is not in
> KeyGroupRange{startKeyGroup=0, endKeyGroup=42}
>
> This may be caused by a number of issues including:
> 1) Unstable hash and equals methods on their key objects
> 2) Improper use of DataStreamUtils#reinterpretAsKeyedStream
>
> Key group ranges are a fairly low level detail that most users will be
> unfamiliar with when working with Flink. We should offer more comprehensive
> error messaging that outlines likely causes and solutions.
>
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
