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
