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https://issues.apache.org/jira/browse/FLINK-6472?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17328780#comment-17328780
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Flink Jira Bot commented on FLINK-6472:
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This major issue is unassigned and itself and all of its Sub-Tasks have not 
been updated for 30 days. So, it has been labeled "stale-major". If this ticket 
is indeed "major", please either assign yourself or give an update. Afterwards, 
please remove the label. In 7 days the issue will be deprioritized.

> BoundedOutOfOrdernessTimestampExtractor does not bound out of orderliness
> -------------------------------------------------------------------------
>
>                 Key: FLINK-6472
>                 URL: https://issues.apache.org/jira/browse/FLINK-6472
>             Project: Flink
>          Issue Type: Bug
>          Components: API / DataStream
>    Affects Versions: 1.3.0
>            Reporter: Elias Levy
>            Priority: Major
>              Labels: stale-major
>
> {{BoundedOutOfOrdernessTimestampExtractor}} attempts to emit watermarks that 
> lag behind the largest observed timestamp by a configurable time delta.  It 
> fails to so in some circumstances.
> The class extends {{AssignerWithPeriodicWatermarks}}, which generates 
> watermarks in periodic intervals.  The timer for this intervals is a 
> processing time timer.
> In circumstances where there is a rush of events (restarting Flink, unpausing 
> an upstream producer, loading events from a file, etc), many events with 
> timestamps much larger that what the configured bound would normally allow 
> will be sent downstream without a watermark.  This can have negative effects 
> downstream, as operators may be buffering the events waiting for a watermark 
> to process them, thus leading the memory growth and possible out-of-memory 
> conditions.
> It is probably best to have a bounded out of orderliness extractor that is 
> based on the punctuated timestamp extractor, so we can ensure that watermarks 
> are generated in a timely fashion in event time, with the addition of process 
> time timer to generate a watermark if there has been a lull in events, thus 
> also bounding the delay of generating a watermark in processing time. 



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