Sockeye

Added

- Inference option `--mc-dropout` to use dropout during inference, leading to non-deterministic output. This option uses the same dropout parameters present in the model config file.

Added

- Added `sockeye.rerank` option `--output` to specify output file.
- Added `sockeye.rerank` option `--output-reference-instead-of-blank` to output reference line instead of best hypothesis when best hypothesis is blank.

Added

- Training option `--quiet-secondary-workers` that suppresses console output for secondary workers when training with Horovod/MPI.
- Set version of isort to `<5.0.0` in requirements.dev.txt to avoid incompatibility between newer versions of isort and pylint.

Added

- Batch type option `max-word` for max number of words including padding tokens (more predictable memory usage than `word`).
- Batching option `--batch-sentences-multiple-of` that is similar to `--round-batch-sizes-to-multiple-of` but always rounds down (more predictable memory usage).

Changed

- Default bucketing settings changed to width 8, max sequence length 95 (96 including BOS/EOS tokens), and no bucket scaling.
- Argument `--no-bucket-scaling` replaced with `--bucket-scaling` which is False by default.

Changed

- Updated `sockeye.rerank` module to use "add-k" smoothing for sentence-level BLEU.

Fixed

- Updated `sockeye.rerank` module to use current N-best format.

Changed

- Changed to a cross-entropy loss implementation that avoids the use of SoftmaxOutput.