Stream.union doesn't change the parallelism of the new stream?

[Ajay Tripathy]

It seems, at least in Flink 1.3.2, unioning two streams together doesn't change the parallelism, and that the new stream just retains the parallelism of the stream in the first. Does it make sense for the parallelism of the new stream to be set to the max of the two streams parallelism? Do I have to make a manual call for this every time?

[Fabian Hueske-2]

Hi,

Union is not an actual operator in Flink. Instead, the operator that is applied on the unioned stream ingests its input from all unioned streams.

The parallelism of that operator is the configured default parallelism (can be specified at the execution environment) unless it is explicitly defined by calling setParallelism().

Best, Fabian

2018-05-03 22:29 GMT+02:00 Ajay Tripathy <[hidden email]>:

It seems, at least in Flink 1.3.2, unioning two streams together doesn't change the parallelism, and that the new stream just retains the parallelism of the stream in the first. Does it make sense for the parallelism of the new stream to be set to the max of the two streams parallelism? Do I have to make a manual call for this every time?