Hi Tim, I think you could use Flink's trigger API [1] to implement a trigger which fires when it sees a certain event or after some time.
[1] https://ci.apache.org/projects/flink/flink-docs-stable/dev/stream/operators/windows.html#triggers Cheers, Till On Wed, Apr 28, 2021 at 5:25 PM Tim Josefsson <tim.josefs...@webstep.se> wrote: > Hello! > > I'm trying to figure out how to implement a window that will emit events > at regular intervals or when a specific event is encountered. > > A bit of background. I have a stream of events from devices that will send > events to our system whenever a user watches a video. These events include > a unique id (sessionId) shared by all events of the same same session so I > want to key my stream on this. After that I want to aggregate all the > events into a session summary and this summary I want to emit every 5 > minutes however I still want to keep the summary in the window (in case > more events for that session arrives). However if I were to receive an end > event (sent by the device once a user stops watching the video) I want to > emit the summary and remove it from the window. > > Is it possible to do this with one of the existing windows together with a > trigger or in some other way? Been trying to figure it out by reading the > docs but haven't gotten any wiser so turning to the mailing list for help. > > Best regards, > Tim >
