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From Till Rohrmann <trohrm...@apache.org>
Subject Re: Cannot see all events in window apply() for big input
Date Tue, 08 Nov 2016 18:00:18 GMT
Flink does not support per key watermarks or type sensitive watermarks. The
underlying assumption is that you have a global watermark which defines the
progress wrt to event time in your topology.

The easiest way would be to have an input which has a monotonically
increasing timestamp. Alternatively you can define the maximum lag between
the watermark and the timestamp and then generate watermarks with w =
timestamp - maxLag. That way you allow elements to be out of order for a
certain amount of event time.


On Tue, Nov 8, 2016 at 5:02 PM, Sendoh <unicorn.banachi@gmail.com> wrote:

> Thank you for confirming.
> What would you think an efficient way not having global watermark? The
> following logic fails to build Watermark per KeyStream:
> jsonStreams.keyBy(new JsonKeySelector()).assignTimestampsAndWatermarks(new
> JsonWatermark()).keyBy(JsonKeySelector()).window(....
> So, using split(), or implementing an event type recognized
> AssignerWithPeriodicWatermarks along with custom EventTimeTrigger would be
> the solution?
> Best,
> Sendoh
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