Interesting, didn’t know about the scaling of num_workers.
I just peeked into your Colab and it is clear it is working that way. Probably what was happening is that, as long as scaling is on (when num_workers is smaller than 8) the system works as num_workers is low but when scaling is off, after passing a certain threshold (in this case 8), it can’t handle that many workers. This threshold (max num_workers) probably varies depending on the instance.
Will be experimenting to find the sweet spot for my specific case. Thanks!