Hi All,
The document said "a window is created as soon as the first element
that should belong to this window arrives, and the window is
completely removed when the time (event or processing time) passes its
end timestamp plus the user-specified allowed lateness (see Allowed
Lateness).".
I am sti
Hi,
this depends on the window type. Tumbling and Sliding Windows are (by
default) aligned with the epoch time (1970-01-01 00:00:00).
For example a tumbling window of 2 hour starts and ends every two hours,
i.e., from 12:00:00 to 13:59:59.999, from 14:00:00 to 15:59:59.999, etc.
The documentation
OK, I see.
But what if a window contains no elements? Is it still get fired and
invoke the window function?
2017-12-12 15:42 GMT+08:00 Fabian Hueske :
> Hi,
>
> this depends on the window type. Tumbling and Sliding Windows are (by
> default) aligned with the epoch time (1970-01-01 00:00:00).
> Fo
No, that's exactly what is mean by "a window is created when the first
element arrives".
Otherwise, you'd have to fire empty windows for all possible keys (in case
of a window operator on a keyed stream) which is obviously not possible.
2017-12-12 9:30 GMT+01:00 Jinhua Luo :
> OK, I see.
>
> But
If the window contains only one element, no more elements come in,
then by default (with EventTimeTrigger), the window would be fired by
next element if that element advances watermark which passes the end
of the window, correct?
That is, even if the window ends at 12:30, then if no more element
co
Unless I generate event-time watermark continuously regardless of elements?
Just like the doc does, it gives an example how to generate continuous
watermark based on processing time (TimeLagWatermarkGenerator):
https://ci.apache.org/projects/flink/flink-docs-release-1.3/dev/event_timestamps_waterm
Hi,
Yes, those last two comments about the watermark and window triggering are
correct. The watermark either has to advance based on events or based on some
continuous generation.
Best,
Aljoscha
> On 13. Dec 2017, at 06:08, Jinhua Luo wrote:
>
> Unless I generate event-time watermark continu
