some confuse for data exchange of parallel operator

[tangkailin]

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

[Biao Liu]

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

On Mon, Aug 5, 2019 at 4:59 PM tangkailin <[hidden email]> 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