Hi Federico,
For your given input and pattern there should (and there are) only two
timeouted patterns:
5> Left(Map(start -> List(Event(100,2017-11-05T03:56:02))))
5> Left(Map(start -> List(Event(100,2017-11-05T06:00:02))))
It is because in your patterns say the next event after events with value
>=100 should not have value >= 100 . And within your timeout there is no
sequence of events where (>=100)+ (<100).
But I will try to explain how it works with the same input for Pattern:
Pattern[Event].begin("start").where(_.value >=100).oneOrMore
.notNext("end").where(_.value <100).within(Time.minutes(30))
Then we have matches:
5> Right(Map(start -> List(Event(100,2017-11-05T03:50:02))))
5> Right(Map(start -> List(Event(100,2017-11-05T03:50:02),
Event(100,2017-11-05T03:52:02))))
5> Right(Map(start -> List(Event(100,2017-11-05T03:52:02))))
5> Right(Map(start -> List(Event(100,2017-11-05T03:50:02),
Event(100,2017-11-05T03:52:02), Event(100,2017-11-05T03:54:02))))
5> Right(Map(start -> List(Event(100,2017-11-05T03:52:02),
Event(100,2017-11-05T03:54:02))))
5> Right(Map(start -> List(Event(100,2017-11-05T03:54:02))))
and timeouted partial matches:
5> Left(Map(start -> List(Event(100,2017-11-05T03:50:02),
Event(100,2017-11-05T03:52:02), Event(100,2017-11-05T03:54:02),
Event(100,2017-11-05T03:56:02))))
5> Left(Map(start -> List(Event(100,2017-11-05T03:52:02),
Event(100,2017-11-05T03:54:02), Event(100,2017-11-05T03:56:02))))
5> Left(Map(start -> List(Event(100,2017-11-05T03:54:02),
Event(100,2017-11-05T03:56:02))))
5> Left(Map(start -> List(Event(100,2017-11-05T03:56:02))))
5> Left(Map(start -> List(Event(100,2017-11-05T06:00:02))))
Right now (in flink 1.3.2) pattern can start on each event (in 1.4 you will
be able to specify AFTER_MATCH_SKIP strategy see:
https://issues.apache.org/jira/browse/FLINK-7169), therefore you see
matches starting at 2017-11-05T03:50:02, 2017-11-05T03:52:02,
2017-11-05T03:54:02.
Also right now the oneOrMore is not greedy (in 1.4 you will be able to
alter it see: https://issues.apache.org/jira/browse/FLINK-7147), therefore
you see matches like: List(Event(100,2017-11-05T03:50:02)) and
List(Event(100,2017-11-05T03:50:02),
Event(100,2017-11-05T03:52:02)) rather than only one of those.
The timeoute partial matches are returned because within the timeout there
was no event with value <100 (in fact there was no event at all to be
checked).
Hope this "study" helps you understand the behaviour. If you feel I missed
something, please provide some example I could reproduce.
Regards,
Dawid
2017-11-07 11:29 GMT+01:00 Ufuk Celebi <u...@apache.org>:
> Hey Frederico,
>
> let me pull in Dawid (cc'd) who works on CEP. He can probably clarify
> the expected behaviour here.
>
> Best,
>
> Ufuk
>
>
> On Mon, Nov 6, 2017 at 12:06 PM, Federico D'Ambrosio
> <federico.dambro...@smartlab.ws> wrote:
> > Hi everyone,
> >
> > I wanted to ask if FlinkCEP in the following scenario is working as it
> > should, or I have misunderstood its functioning.
> >
> > I've got a keyedstream associated with the following pattern:
> >
> > Pattern[Event].begin("start").where(_.value >=100).oneOrMore
> > .notNext("end").where(_.value >=100).within(Time.minutes(30))
> >
> > Considering a single key in the stream, for simplicity, I've got the
> > following sequence of events (using EventTime on the "time" field of the
> > json event):
> >
> > {value: 100, time: "2017-11-05 03:50:02.000"}
> > {value: 100, time: "2017-11-05 03:52:02.000"}
> > {value: 100, time: "2017-11-05 03:54:02.000"}
> > {value: 100, time: "2017-11-05 03:56:02.000"} // end of events within
> the 30
> > minutes from the first event
> > {value: 100, time: "2017-11-05 06:00:02.000"}
> >
> > Now, when it comes to the select/flatselect function, I tried printing
> the
> > content of the pattern map and what I noticed is that, for example, the
> > first 2 events weren't considered in the same pattern as the map was like
> > the following:
> >
> > {start=[{value: 100, time: 2017-11-05 03:50:02.000}]}
> > {start=[{value: 100, time: 2017-11-05 03:52:02.000}]}
> >
> > Now, shouldn't they be in the same List, as they belong to the same
> > iterative pattern, defined with the oneOrMore clause?
> >
> > Thank you for your insight,
> > Federico D'Ambrosio
>
