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 >>> >> >
