Thanks for the suggestions! I'll see if I can implement something that works! A followup question, more related to state. If I implement either the custom trigger with or the process function, how will they handle crashes and such. So if I for instance have a checkpointing interval of 10s will the job recover from the last checkpoint with all the summaries as they were at that point. Or do I have to implement specific ValueStates in both cases?
On Thu, 29 Apr 2021 at 10:25, Till Rohrmann <trohrm...@apache.org> wrote: > 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 >> > -- *Tim Josefsson* [image: Webstep GPtW] <http://www.webstep.se/> mobil +46 (0) 707 81 91 12 telefon +46 (0) 8 21 40 70 tim.josefs...@webstep.se *webstep.se <http://www.webstep.se/>* Suttungs gränd 2 753 19 Uppsala Stockholm | Uppsala | Malmö | Sundsvall | Oslo Bergen | Stavanger | Trondheim | Kristiansand [image: LinkedIn] <http://www.linkedin.com/company/webstep-ab> [image: Facebook] <http://www.facebook.com/webstepAB> [image: Facebook] <http://www.instagram.com/webstep_sverige>
