[
https://issues.apache.org/jira/browse/FLINK-16193?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17041272#comment-17041272
]
Seth Wiesman commented on FLINK-16193:
--------------------------------------
[~aljoscha]
This is tricky because key group ranges are not validated in one place but all
over the codebase, at low-level places around the state backends. I _think_ we
could simply include a check at AbstractStreamOperator#setKeyContextElement and
throw an exception there. This seems safe to me but I want to double check.
> 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
> 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)
