Unforunately there is mistake in the docs the return type should be DataStream rather than SingleOuputStream
The correct version should be:
val patternStream: PatternStream[Event] = CEP.pattern(input, pattern)
val outputTag = OutputTag[String]("side-output")
val result: DataStream[ComplexEvent] = patternStream.select(outputTag){
(pattern: Map[String, Iterable[Event]], timestamp: Long) =>
TimeoutEvent()
} {
pattern: Map[String, Iterable[Event]] => ComplexEvent()
}
This syntax is only available in 1.4 though, in previous versions timeouted
events were not returned via sideOutput.
> On 8 Nov 2017, at 12:18, Federico D'Ambrosio <federico.dambro...@smartlab.ws>
> wrote:
>
> Thank you very much, Dawid, for your thorough explanation, really useful. I
> totally missed the distinction between timed-out events and complete matches.
>
> I'd like to ask you one more thing, about the flinkCEP scala api: in the
> documentation, there is the following code:
>
> val patternStream: PatternStream[Event] = CEP.pattern(input, pattern)
>
>
>
> val outputTag = OutputTag[String]("side-output")
>
>
>
> val result: SingleOutputStreamOperator[ComplexEvent] =
> patternStream.select(outputTag){
>
>
> (pattern: Map[String, Iterable[Event]], timestamp: Long) => TimeoutEvent()
> } {
>
>
> pattern: Map[String, Iterable[Event]] => ComplexEvent()
> }
>
> where result would then be used to get outputtag side output.
> If I paste this code I get that the select function is missing its parameters
> ("Unspecified value parameters: patternSelectFunction:
> PatternSelectFunction[ComplexEvent, NotInferredR]""),
> while, If I add the parameters explicitly such as
>
> patternStream.select[TimeoutEvent, ComplexEvent]
>
> I get "Too many arguments for select". Am I missing something?
>
> Thank you very much,
> Federico
>
> 2017-11-07 16:34 GMT+01:00 Dawid Wysakowicz <wysakowicz.da...@gmail.com>:
> 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
>
>
>
>
> --
> Federico D'Ambrosio
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