this

from fastai.callbacks.tensorboard import LearnerTensorboardWriter

doesn’t exist anymore in fastai2

Hmm we should definitely update the example to fastai2 API

maybe the fastai bindings in clearml package are outdated

Are you getting any scalars reported to clearml?

they also appear to be relying on the tensorboard callback which seems not to work on distributed training

Yes that is correct, usually the way it works all nodes report back to "master" node, and that one performs the TB writes.
PricklyRaven28 who is spinning the sub-processes in your example?
EDIT: sorry found it:
python -m fastai.launch <script>