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Fairseq(-py) is a sequence modeling toolkit that allows researchers and developers to train custom models for translation, summarization, language modeling and other text generation tasks.

Usage

This clone of fairseq supports Knowledge Distillation, Recurrent Stacking, LoRA RoPE, and ALiBi, for the Transformer model and the translation task. You can add the following flags to fairseq-train/fairseq-interactive/fairseq-generate to use them:

Name and Citation	Description	Flags to Activate	Source
Knowledge Distillation (Hinton et al., Kim & Rush, Wang et al., Gumma et al.)	Transfers soft information from a pretrained teacher model to a smaller student model. Please check here for a detailed description of the arguments.	--teacher-checkpoint-path $path --task seq2seq_lm_distillation --criterion lm_distillation_loss --kd-args '{"strategy": "on_policy", "lambda": 1.0, "loss_type": "forward_kld"}'	Selective Distillation
Recurrent Stacking (Dabre & Fujita)	Extreme parameter sharing technique in which all layers in the encoder/decoder are shared	--encoder-recurrent-stacking 6 --decoder-recurrent-stacking 6	-
Low-Rank Adaptation (LoRA) (Hu et al.)	Efficient model adaptation technique that modifies a small number of model parameters while freezing the rest.	--lora-args '{"r": 8, "alpha": 16, "dropout": 0.05, "bias": "none, "target_modules": "k_proj,v_proj", "rank_scaled": false}' --attn-implementation fast --load-checkpoint-liberally	LoRA Implementation
Rotary Positional Embedding (RoPE) (Su et al.)	Encodes absolute position with a rotation matrix and incorporates explicit relative position dependency in self-attention formulation	--rope-args '{"theta": 10000, "use_xpos": false, "xpos_scale_base": 512}' --attn-implementation fast --no-token-positional-embeddings --load-checkpoint-liberally	RoPE Implementation
Gated Linear Unit (GLU) (Shazeer)	A better Feed-Forward-Network variant	--encoder-use-glu --decoder-use-glu	GLU Implementation
RMSNorm (Zhang and Sennrich)	An efficient normalization technique	--encoder-use-rmsnorm --decoder-use-rmsnorm	RMSNorm Implementation
Attention with Linear Biases (ALiBi) (Press et al.)	Simple and efficient position method that biases query-key attention scores with a penalty proportional to their distance	--alibi-args '{"type": "symmetrical"}' --no-token-positional-embeddings --load-checkpoint-liberally	ALiBi Implementation
Factorized Embedding Parameterization (Lan et al.)	Parameterizes large embeddings by adding an intermediate bottleneck layer	--encoder-factorized-embed-dim 128 --decoder-factorized-embed-dim 128	-
Sanity Validation Steps	Runs a full pass over the validation set at the beginning of training	--run-sanity-validation-steps	-
Efficient Multihead Attention (MHA)	A torch-functional variant of MultiHeadAttention	--attn-implementation fast. By default, the value is fairseq	-
Grouped Query Attention (GQA) (Ainslie et al.)	Clusters queries into groups, allowing for more efficient computation and enhanced scalability in processing large sets of queries within transformer models.	--attn-implementation fast_gqa	GQA Implementation
Fused Attention	Combines the efficiency of Multi-Head Attention (MHA) and Grouped Query Attention (GQA) into a fused operation, providing faster computation. This fused version is not compatible with models trained using the unfused versions of MHA or GQA.	--attn-implementation fast_fused or --attn-implementation fast_gqa_fused	Fused Implementation

Upcoming features ($\alpha$-testing)

• --bf16 has been decoupled from --tpu, and can be used independently to train the model with bfloat16. Note, for models pretrained using fp16, bf16 inference of finetuning can yield highly unpredictable results.
• --torch-compile $mode can be used in the interactive and generate methods for faster inference.

Requirements and Installation

• PyTorch version >= 2.4.1
• Python version >= 3.10, <= 3.12
• For training new models, you'll also need an NVIDIA GPU and NCCL
• To install fairseq and develop locally:

git clone https://github.com/VarunGumma/fairseq
cd fairseq
pip install -e ./

or To install directly:

pip install git+https://github.com/VarunGumma/fairseq.git

• For faster training install NVIDIA's apex library:

git clone https://github.com/NVIDIA/apex
cd apex
pip install -v --no-cache-dir --global-option="--cpp_ext" --global-option="--cuda_ext" \
  --global-option="--deprecated_fused_adam" --global-option="--xentropy" \
  --global-option="--fast_multihead_attn" ./

• For large datasets install PyArrow: pip install pyarrow
• If you use Docker make sure to increase the shared memory size either with --ipc=host or --shm-size as command line options to nvidia-docker run.

License

fairseq(-py) is MIT-licensed. The license applies to the pre-trained models as well.

Citation

Please cite as:

@inproceedings{gumma-etal-2023-empirical,
    title = "An Empirical Study of Leveraging Knowledge Distillation for Compressing Multilingual Neural Machine Translation Models",
    author = "Gumma, Varun  and
      Dabre, Raj  and
      Kumar, Pratyush",
    editor = "Nurminen, Mary  and
      Brenner, Judith  and
      Koponen, Maarit  and
      Latomaa, Sirkku  and
      Mikhailov, Mikhail  and
      Schierl, Frederike  and
      Ranasinghe, Tharindu  and
      Vanmassenhove, Eva  and
      Vidal, Sergi Alvarez  and
      Aranberri, Nora  and
      Nunziatini, Mara  and
      Escart{\'\i}n, Carla Parra  and
      Forcada, Mikel  and
      Popovic, Maja  and
      Scarton, Carolina  and
      Moniz, Helena",
    booktitle = "Proceedings of the 24th Annual Conference of the European Association for Machine Translation",
    month = jun,
    year = "2023",
    address = "Tampere, Finland",
    publisher = "European Association for Machine Translation",
    url = "https://aclanthology.org/2023.eamt-1.11",
    pages = "103--114",
    abstract = "Knowledge distillation (KD) is a well-known method for compressing neural models. However, works focusing on distilling knowledge from large multilingual neural machine translation (MNMT) models into smaller ones are practically nonexistent, despite the popularity and superiority of MNMT. This paper bridges this gap by presenting an empirical investigation of knowledge distillation for compressing MNMT models. We take Indic to English translation as a case study and demonstrate that commonly used language-agnostic and language-aware KD approaches yield models that are 4-5x smaller but also suffer from performance drops of up to 3.5 BLEU. To mitigate this, we then experiment with design considerations such as shallower versus deeper models, heavy parameter sharing, multistage training, and adapters. We observe that deeper compact models tend to be as good as shallower non-compact ones and that fine-tuning a distilled model on a high-quality subset slightly boosts translation quality. Overall, we conclude that compressing MNMT models via KD is challenging, indicating immense scope for further research.",
}

@inproceedings{ott2019fairseq,
  title = {fairseq: A Fast, Extensible Toolkit for Sequence Modeling},
  author = {Myle Ott and Sergey Edunov and Alexei Baevski and Angela Fan and Sam Gross and Nathan Ng and David Grangier and Michael Auli},
  booktitle = {Proceedings of NAACL-HLT 2019: Demonstrations},
  year = {2019},
}

and please add a footnote url to this repository.

Final Note

I will try my best to keep this repo synced with the upstream fairseq repository. This clone is very dynamic and can have broken stuff once in a while. So feel free to raise issues or pull requests to clear any bugs or introduce new features.