Hi, why in BATCH mode Flink only process 1 task at a time? In the image at least reading from the sources could certainly be executed in parallel...

How many slots does your cluster have?

I guess this answers my question 🫠

Ah, for batch job, each task needs an exclusive slot. Without enough slots, those sources in your example cannot be executed in parallel, and can only be executed one after another.

Yeah, raising

taskmanager.numberOfTaskSlots

to 4 solved it. Thank you so much!