[jira] [Created] (FLINK-25850) Consider notifying nested state backend about checkpoint abortion

["Roman Khachatryan (Jira)" <ji...@apache.org>]

Roman Khachatryan created FLINK-25850:
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             Summary: Consider notifying nested state backend about checkpoint abortion
                 Key: FLINK-25850
                 URL: https://issues.apache.org/jira/browse/FLINK-25850
             Project: Flink
          Issue Type: Sub-task
          Components: Runtime / State Backends
            Reporter: Roman Khachatryan
             Fix For: 1.16.0


The notification is optional, but some backends might do GC upon receiving it.
{code}
These notifications are "best effort", meaning they can sometimes be skipped.
This method is very rarely necessary to implement.
{code}

The usefulness is also limited by:
- low probability of notification reaching backend because of the difference in intervals and cleanup on checkpoint completion
- low probability of backends making good use of it because it's delivered after snapshot is done; and backends must be resilient to missing notifications

There is added complexity and risk (such as FLINK-25816).
Probably, complexity can be eliminated by extracting some Notifier class from ChangelogStateBackend.

cc: [~yunta]



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