Unless you have a good reason not to, you should use either TensorFlow or PyTorch.
Both frameworks are converging to a point where they are good for research and production.
fast.ai is a solid option for beginners who want to iterate quickly.
Distributed training of neural networks can be approached in 2 ways: (1) data parallelism and (2) model parallelism.
Practically, data parallelism is more popular and frequently employed in large organizations for executing production-level deep learning algorithms.
Model parallelism, on the other hand, is only necessary when a model does not fit on a single GPU.
Ray is an open-source project for effortless, stateful, parallel, and distributed computing in Python.
Horovod is Uber’s open-source distributed deep learning framework that uses a standard multi-process communication framework, so it can be an easier experience for multi-node training.