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https://issues.apache.org/jira/browse/FLINK-18429?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Stephan Ewen closed FLINK-18429.
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> Add default method for
> CheckpointListener.notifyCheckpointAborted(checkpointId)
> -------------------------------------------------------------------------------
>
> Key: FLINK-18429
> URL: https://issues.apache.org/jira/browse/FLINK-18429
> Project: Flink
> Issue Type: Bug
> Components: API / DataStream
> Reporter: Stephan Ewen
> Assignee: Stephan Ewen
> Priority: Blocker
> Labels: pull-request-available
> Fix For: 1.11.0
>
>
> The {{CheckpointListener}} interface is implemented by many users. Adding a
> new method {{notifyCheckpointAborted(long)}} to the interface without a
> default method breaks many user programs.
> We should turn this method into a default method:
> - Avoid breaking programs
> - It is in practice less relevant for programs to react to checkpoints
> being aborted then to being completed. The reason is that on completion you
> often want to commit side-effects, while on abortion you frequently do not do
> anything, but let the next successful checkpoint commit all changes up to
> then.
> *Original Confusion*
> There was confusion about this originally, going back to a comment by myself
> suggesting this should not be a default method, incorrectly thinking of it as
> an internal interface:
> https://github.com/apache/flink/pull/8693#issuecomment-542834147
> See also clarification email on the mailing list:
> {noformat}
> About the "notifyCheckpointAborted()":
> When I wrote that comment, I was (apparently wrongly) assuming we were
> talking about an
> internal interface here, because the "abort" signal was originally only
> intended to cancel the
> async part of state backend checkpoints.
> I just realized that this is exposed to users - and I am actually with Thomas
> on this one. The
> "CheckpointListener" is a very public interface that many users implement.
> The fact that it is
> tagged "@PublicEvolving" is somehow not aligned with reality. So adding the
> method here will
> in reality break lots and lots of user programs.
> I think also in practice it is much less relevant for user applications to
> react to aborted checkpoints.
> Since the notifications there can not be relied upon (if there is a task
> failure concurrently) users
> always have to follow the "newer checkpoint subsumes older checkpoint"
> contract, so the abort
> method is probably rarely relevant.
> This is something we should change, in my opinion.
> {noformat}
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