Vietnamese Text Summarization with Poem

Summarize a piece of text with poem. Doesn't it sound fun?

Introduction

Jokes aside, this is a fun project by my team at FPT University about fine-tuning a Large Language Model (LLM) at summarizing a piece of long Vietnamese text in the form of poems. We call the model VistralPoem5.
Here's a little example:

HuggingFace 🤗

from transformers import AutoTokenizer, AutoModelForCausalLM

model_name = "andythetechnerd03/VistralPoem5"
tokenizer = AutoTokenizer.from_pretrained(model_name, device_map="auto")
model = AutoModelForCausalLM.from_pretrained(model_name, device_map="auto")

inputs = [
    {"role": "system", "content": "Bạn là một nhà thơ chuyên nghiệp, nhiệm vụ của bạn là chuyển bài văn này thành 1 bài thơ 5 chữ từ khoảng 1 đến 3 khổ"},
    {"role": "user", "content": "nhớ tới lời mẹ dặn\nsợ mẹ buồn con đau\nnên tự mình đứng dậy\nnhanh như có phép màu"}
]

input_ids = tokenizer.apply_chat_template(inputs, return_tensors="pt").to(model.device)
outputs = model.generate(
    input_ids=input_ids,
    max_new_tokens=200,
    do_sample=True,
    top_p=0.95,
    top_k=20,
    temperature=0.1,
    repetition_penalty=1.05,
)

output_str = tokenizer.batch_decode(outputs[:, input_ids.size(1): ], skip_special_tokens=True)[0].strip()
print(output_str)

Fine-tuning

This is not an easy task. The model we are using is a Vietnamese version of the popular Mistral-7B with 7 billion parameters. Obviously, it is very computationally expensive to fine-tune, therefore we applied various state-of-the-art optimization techniques:

• Flash Attention: helps reduce computation complexity of Attention from $O(n^2)$ to $O(n\log n)$
• QLoRA (Quantized Low-Rank Adaptation): train a smaller "adapter" which is a low-rank weight matrices, allowing for less computation. Furthermore, the base model is quantized to only 4-bit, this is great for storing large models.
• Mixed Precision Training: here we combine float32 with bfloat16 data type for faster training.

To train the LLM seamlessly as possible, we used a popular open-source fine-tuning platform called Axolotl. This platform helps you declare the parameters and config and train quickly without much code.

Code for fine-tuning model

To customize the configuration, you can modify the create_file_config.py file. After making your changes, run the script to generate a personalized configuration file. The following is an example of how to execute the model training:

cd src
export PYTHONPATH="$PWD"
accelerate launch -m axolotl.cli.train config.yaml

Data

This is not easy. Such data that takes the input as a long text (newspaper article, story) and output a poem is very hard to find. So we created our own... by using prompt engineering.

• The collection of poems is straightforward. There are many repositories and prior works that collected a handful of Vietnamese poems, as well as publicly available samples online. We collected from FPT Software AI Lab and HuggingFace.
• From the poems we use prompt engineering to ask our base model to generate a story from such poem. The prompt is in the form
  Bạn là một nhà kể chuyện phiếm, nhiệm vụ của bạn là hãy kể 1 câu chuyện đơn giản và ngắn gọn từ một bài thơ, câu chuyện nên là 1 bài liền mạch, thực tế\n\n{insert poem here}
• Speaking of prompt engineering, there is another prompt to generate poem from context.
  Bạn là một nhà thơ chuyên nghiệp, nhiệm vụ của bạn là chuyển bài văn này thành 1 bài thơ 5 chữ từ khoảng 1 đến 3 khổ: \n {insert context here}
• The pre-processing step is faily simple. A bit of lowercase here, punctuation removal there, plus reducing poems to 1-3 random paragraphs, and we are done.

After all, we have about 72,101 samples with a ratio of 0.05 (68495 on the train set and 3606 on the test set)

We published the dataset at here

Custom Evaluation Data

As part of the final evaluation for benchmark, we gathered around 27 Vietnamese children's stories and divided into many samples, accumulating to 118 samples. The dataset can be found here

Model

As mentioned earlier, we use Vistral-7B-Chat as the base model and we fine-tune it on our curated dataset earlier. Here's a few configurations:

• The model is based on Transformer’s decoder-only architechture:
• Number of Attention Heads: 32
• Hidden Size: 4096
• Vocab size: 38369
• Data type: bfloat16
• Number of Hidden Layers (Nx): 32
• Loss function: Cross-entropy
• Parameter-Efficient Finetuning: QLora
  • 4 bit
  • Alpha: 16
  • Rank: 32
  • Target: Linear
• Gradient accumulation: 4
• Learning Rate: 0.0002
• Warmup Steps: 10
• LR Scheduler: Cosine
• Max Steps: 400
• Batch size: 16
• Optimizer: Adamw bnb 8bit
• Sequence Len: 1096

The weights can be found here

The notebook for training can be found at notebook/Fine_tune_LLMs_with_Axolotl.ipynb

Benchmark

We used the custom evaluation dataset to perform benchmark. Since popular metrics such as ROUGE is not applicable to poem format, we chose a simpler approach - counting the probability of 5-word poems in the result.
Here's the result:

Model	Number of Parameters	Hardware	Probability of 5-word(Higher is better)	Average inference time(Lower is better)
Vistral-7B-Chat (baseline)	7B	1x Nvidia Tesla A100	4.15%	6.75s
Google Gemini Pro*	> 100B	Multi-TPU	18.3%	3.4s
VistralPoem5 (Ours)	7B	1x Nvidia Tesla A100	61.4%	3.14s

* API call, meaning inference time may be affected

The benchmark code can be found at notebook/infer_poem_model.ipynb and notebook/probability_5word.ipynb

Deployment

We used Gradio for fast deployment on Google Colab. It should be in notebook/infer_poem_model.ipynb as well.

Docker Image, coming soon...

Future Work

• Make a custom loss function to align rhythm and tones.
• Use a better metric for evaluating poems (rhythm and content summarization)
• Use RLHF to align poems with human values.
• And more...

Credits

• Phan Phuc for doing the fine-tuning.
• Me for designing the pipeline and testing the model.
• Truong Vo for collecting the data.