Hi Rong, Thanks for your reply. :)
Best regards/祝好, Chang Liu 刘畅 > On 19 Sep 2018, at 18:20, Rong Rong <walter...@gmail.com> wrote: > > Hi Chang, > > There were some previous discussion regarding how to debug watermark and > window triggers[1]. > Basically if there's no data for some partitions there's no way to advance > watermark. As it would not be able to determine whether this is due to > network failure or actually there's no data arriving at the source. > I think your use case is better of using SlidingProcessingTimeWindow. > > Thanks, > Rong > > [1] > http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/watermark-does-not-progress-td22315.html > > <http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/watermark-does-not-progress-td22315.html> > On Wed, Sep 19, 2018 at 1:48 AM Chang Liu <fluency...@gmail.com > <mailto:fluency...@gmail.com>> wrote: > Dear All, > > I have a question about the Window Trigger: let’s say i would like like use > the SlidingEventTimeWindow (60 seconds window size + 1 second window shift) > to count the number of records per window. And I am using Event Time with > periodic watermarking with certain maxOurOfOrderness time. > > Sometimes, what happens is: during certain time, there is no incoming event, > and then the watermark for triggering the window fire is not coming. Then, > the last several records will be just stayed in the window. It will fire > only when the window sees the watermark to trigger. > > What I would like to achieve is: if there is no just watermark coming within > certain time (maybe this time is system clock time?), I can still trigger the > window to fire no matter whether there is new event coming or not. Then I can > still get the window count for this window, without waiting the next event, > which could be coming after a long time. > > Do you have any idea how can I do this? Many Thanks :) > > Best regards/祝好, > > Chang Liu 刘畅 > >
