For what it's worth, we have a trigger that fires once a day for a recurring calculation. When an element comes in, we set the trigger context's processing time timer to the exact millisecond of the desired time. The predefined triggers were useful to look at to achieve this: https://github.com/apache/flink/tree/master/flink-streaming-java/src/main/java/org/apache/flink/streaming/api/windowing/triggers
Some things I discovered along the way, particularly using processing time, which may be useful: - registering a time that's already passed will cause the timer callback to be called - when the system shuts down, the window is fired even though the trigger has not gone off (this sounds subject to change though) On Tue, Jan 26, 2016 at 3:47 AM, Till Rohrmann <trohrm...@apache.org> wrote: > Hi Radu, > > you can register processing and event time time triggers using the > TriggerContext which is given to the onElement, onProcessingTime and > onEventTime methods of Trigger. In case you register a processing time > timer, the onProcessingTime method will be called once the system clock > has passed the timer time. In case of an event time timer, the onEventTime > method is called once a watermark has been received which has a higher > watermark than the timer. > > I hope this helps you to solve your problem. > > Cheers, > Till > > > On Mon, Jan 25, 2016 at 9:25 PM, Radu Tudoran <radu.tudo...@huawei.com> > wrote: > >> Re-Hi, >> >> >> >> I have another question regarding the triggering of the processing of a >> window. Can this be done in some way at specific time intervals, >> independent of whether an event has been received or not, via a trigger? >> >> >> >> The reason why I am considering a trigger rather than timeWindow(All) is >> that timeWindow will end up generating multiple windows and duplicating >> data, while having the option from the trigger to actually fire the >> processing at certain times, independent of when the events arrived) would >> enable to operate with a single window. >> >> >> >> Regards, >> >> >> >> Dr. Radu Tudoran >> >> Research Engineer - Big Data Expert >> >> IT R&D Division >> >> >> >> [image: cid:image007.jpg@01CD52EB.AD060EE0] >> >> HUAWEI TECHNOLOGIES Duesseldorf GmbH >> >> European Research Center >> >> Riesstrasse 25, 80992 München >> >> >> >> E-mail: *radu.tudo...@huawei.com <radu.tudo...@huawei.com>* >> >> Mobile: +49 15209084330 >> >> Telephone: +49 891588344173 >> >> >> >> HUAWEI TECHNOLOGIES Duesseldorf GmbH >> Hansaallee 205, 40549 Düsseldorf, Germany, www.huawei.com >> Registered Office: Düsseldorf, Register Court Düsseldorf, HRB 56063, >> Managing Director: Bo PENG, Wanzhou MENG, Lifang CHEN >> Sitz der Gesellschaft: Düsseldorf, Amtsgericht Düsseldorf, HRB 56063, >> Geschäftsführer: Bo PENG, Wanzhou MENG, Lifang CHEN >> >> This e-mail and its attachments contain confidential information from >> HUAWEI, which is intended only for the person or entity whose address is >> listed above. Any use of the information contained herein in any way >> (including, but not limited to, total or partial disclosure, reproduction, >> or dissemination) by persons other than the intended recipient(s) is >> prohibited. If you receive this e-mail in error, please notify the sender >> by phone or email immediately and delete it! >> >> >> > >
