The CEP operator maintains for each pattern a window length. This means that every starting event will set its own timeout value.
So if T=51 arrives in the 11th minute, then it depends whether the second T=31 arrived sometime between the 1st and 11th minute. If that's the case, then you should also see a second matching. Cheers, Till On Tue, Aug 2, 2016 at 10:20 PM, Sameer W <sam...@axiomine.com> wrote: > Thanks Till, > > In that case if I have a pattern - > First = T > 30 > Followed By = T > 50 > Within 10 minutes > > If I get the following sequence of events within 10 minutes > T=31, T=51, T=31, T=51 > > I assume the alert will fire twice now. > > But what happens if the last T=51 arrives in the 11th minute. If the > partially matched pattern is discarded after 10 minutes how will the system > detect T=51. Or do you mean that that timer (for the within clause) is > reset each time the patter T>30 matches. In that case it would fire! > > Thanks, > Sameer > > On Tue, Aug 2, 2016 at 10:02 AM, Till Rohrmann <trohrm...@apache.org> > wrote: > >> Hi Sameer, >> >> the within clause of CEP uses neither tumbling nor sliding windows. It is >> more like a session window which is started whenever an element which >> matches the starting condition arrives. As long as new events which fulfill >> the pattern definition arrive within the length of the window, they will be >> added. If the pattern should not be completed within the specified time >> interval, the partially matched pattern will be discarded. If you've >> specified a timeout handler, then the timeout handler is called with the >> partial pattern. >> >> At the moment, there is no way to re-insert elements in the upstream. >> Actually there is also no need for it because the CEP operator will detect >> the alert patterns if there are two temperature readings > 150 within 6 >> seconds. >> >> Cheers, >> Till >> >> >> >> On Tue, Aug 2, 2016 at 5:12 AM, Aljoscha Krettek <aljos...@apache.org> >> wrote: >> >>> +Till, looping him in directly, he probably missed this because he was >>> away for a while. >>> >>> >>> >>> On Tue, 26 Jul 2016 at 18:21 Sameer W <sam...@axiomine.com> wrote: >>> >>>> Hi, >>>> >>>> It looks like the WithIn clause of CEP uses Tumbling Windows. I could >>>> get it to use Sliding windows by using an upstream pipeline which uses >>>> Sliding Windows and produces repeating elements (in each sliding window) >>>> and applying a Watermark assigner on the resulting stream with elements >>>> duplicated. I wanted to use the "followedBy" pattern where there is a >>>> strong need for sliding windows. >>>> >>>> Is there a plan to add sliding windows to the within clause at some >>>> point? >>>> >>>> The PatternStream class's "select" and "flatSelect" have overloaded >>>> versions which take PatternTimeOut variable. Is there a way to insert some >>>> of those elements back to the front of the stream. Say I am trying to find >>>> a pattern where two temperature readings >150 within 6 second window should >>>> raise an alert. If only one was found, can I insert that one back in the >>>> front of the stream on that task node (for that window pane) so that I can >>>> find a pattern match in the events occurring in the next 6 seconds. If I >>>> can do that, I don't need sliding windows. Else I cannot avoid using them >>>> for such scenarios. >>>> >>>> Thanks, >>>> Sameer >>>> >>> >> >
