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Current state: "Under Discussion"

Discussion thread: here

JIRA: KAFKA-12446

Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).

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It is not necessary to review this as part of the KIP process but for those who are interested, here is an early pull request with the proposed changes.

Affected Public Interfaces

KGroupedTable interface 

As a result of the proposed change, all the methods exposed via the `KGroupedTable` interface (i.e.  aggregate , reduce , and count ) will no longer produce inconsistent states in cases where the grouping key has not changed, transient or otherwise, reflecting the improved semantics of a single "atomic" update. For example, consider the following simple topology: 

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