Hi Dominik, A record is already processed once it enters the window. Thus the checkpoint barrier does not get blocked before the window containing the leading records is triggered. A window is actually part of the states of the WindowOperator and the data records processing is to build up this state.
Thanks, Zhu Zhu Dian Fu <dian0511...@gmail.com> 于2019年9月6日周五 下午8:17写道： > When a WindowOperator receives all the barrier from the upstream, it will > forward the barrier to downstream operator and perform the checkpoint > asynchronously. > It doesn't have to wait the window to trigger before sending out the > barrier. > > Regards, > Dian > > > 在 2019年9月6日，下午8:02，Dominik Wosiński <wos...@gmail.com> 写道： > > > > Hello, > > I have a slight doubt on checkpointing in Flink and wanted to clarify my > > understanding. Flink uses barriers internally to keep track of the > records > > that were processed. The documentation[1] describes it as the checkpoint > > was only happening when the barriers are transferred to the sink. So > let's > > consider a toy example of `TumblingEventTimeWindow` set to 5 hours and > > `CheckpointInterval` set to 10 minutes. So, if the documentation is > > correct, the checkpoint should occur only when the window is processed > and > > gets to sink (which can take several hours) , which is not true as far > as I > > know. I am surely wrong somewhere, could someone explain where is the > error > > in my logic ? > > > > > > [1] > > > https://ci.apache.org/projects/flink/flink-docs-stable/internals/stream_checkpointing.html > >
