OpenNMT-tf uses TensorBoard to log information during the training. Simply start tensorboard by setting the active log directory, e.g.:

tensorboard --logdir="."

then open the URL displayed in the shell to monitor and visualize several data, including:

  • training and evaluation loss
  • training speed
  • learning rate
  • gradients norm
  • computation graphs
  • word embeddings
  • decoder sampling probability


OpenNMT-tf supports asynchronous distributed training. The user should set on the command line:

  • a chief worker host that runs a training loop and manages checkpoints, summaries, etc.
  • a list of worker hosts that run a training loop
  • a list of parameter server hosts that synchronize the parameters

Then a training instance should be started on each host with a selected task, e.g.:

CUDA_VISIBLE_DEVICES=0 python -m bin.main train [...] --ps_hosts localhost:2222 --chief_host localhost:2223 --worker_hosts localhost:2224,localhost:2225 --task_type worker --task_index 1

will start the worker 1 on the current machine and first GPU.

For more details, see the documentation of tf.estimator.train_and_evaluate. Also see tensorflow/ecosystem to integrate distributed training with open-source frameworks like Docker or Kubernetes.