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For stream time, the time is advanced before processing a new record that has a time higher than the currently known stream time. Therefore, it is possible that the ProcessorContext#timestamp may be earlier than the streamTime if the records not processed in order by time. It is simply not reliable to use solely timestamp and System.currentTimeMillis() for actions based on time.

Public Interfaces

Update:

This KIP overlaps with KIP-478 and we also added the new methods currentSystemTimeMs() and currentStreamTimeMs() to api.ProcessorContext in 3.2.0 release.

Add new public API for currentSystemTimeMs:

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