Hi Kylin, > Can this map record all data? Or this map only record data from one parallelism of upstream operator? Neither of your guess is correct. It depends on the partitioner between the map operator and upstream operator. You could find more in this document [1].
1. https://ci.apache.org/projects/flink/flink-docs-master/concepts/programming-model.html Thanks, Biao /'bɪ.aʊ/ On Mon, Aug 5, 2019 at 4:59 PM tangkailin <tkl...@126.com> wrote: > Hello, > > I don’t know how parallel operator exchange data in flink. for > example, I define a map in a operator with n (n > 1) parallelism for > counting. Can this map record all data? Or this map only record data from > one parallelism of upstream operator? > > > > Thanks, > > Kylin >