Hello Fabian,

 

thank you for your answer!

 

Does it mean that the operator will wait until get two watermarks from the 
input streams and emits then the “slower” watermark?

 

Best regards

Wei

 

Von: Fabian Hueske [mailto:fhue...@gmail.com] 
Gesendet: Sunday, July 30, 2017 11:17 AM
An: xie wei
Cc: user
Betreff: Re: Is watermark used by joining two streams

 

Periodic and punctuated watermarks only differ in the way that they are 
generated. Afterwards they are treated the same.

An operator with two input streams will always sync its own watermarks to the 
watermarks of both input streams, i.e., to the "slower" watermark of both 
inputs.

So if the left input says it is 12:14 and the right says it is 11:53, the 
operator will have a internal time of 11:53 and emit watermarks according to 
that time.

Hope that helps,

Fabian

 

 

2017-07-28 15:00 GMT+02:00 xie wei <jixia...@googlemail.com>:

Hello,

i want to join two streams based on event time window, every stream has its own 
watermark, one has priodic watermark and the other has punctuated watermark.

are the watermarks used to trigger the join? if yes, which one and how is it 
used?

Thank you and best regards

Wei


 


 

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