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ASF GitHub Bot commented on FLINK-9428: --------------------------------------- Github user StephanEwen commented on the issue: https://github.com/apache/flink/pull/6066 Thanks for the review. Addressing the comments and merging this... > Allow operators to flush data on checkpoint pre-barrier > ------------------------------------------------------- > > Key: FLINK-9428 > URL: https://issues.apache.org/jira/browse/FLINK-9428 > Project: Flink > Issue Type: New Feature > Components: State Backends, Checkpointing > Reporter: Stephan Ewen > Assignee: Stephan Ewen > Priority: Major > Fix For: 1.6.0 > > > Some operators maintain some small transient state that may be inefficient to > checkpoint, especially when it would need to be checkpointed also in a > re-scalable way. > An example are opportunistic pre-aggregation operators, which have small the > pre-aggregation state that is frequently flushed downstream. > Rather that persisting that state in a checkpoint, it can make sense to flush > the data downstream upon a checkpoint, to let it be part of the downstream > operator's state. > This feature is sensitive, because flushing state has a clean implication on > the downstream operator's checkpoint alignment. However, used with care, and > with the new back-pressure-based checkpoint alignment, this feature can be > very useful. > Because it is sensitive, I suggest to make this only an internal feature > (accessible to operators) and NOT expose it in the public API at this point. -- This message was sent by Atlassian JIRA (v7.6.3#76005)