Implementation
Finetune Llama-2-7b on a Google colab¶
Welcome to this Google Colab notebook that shows how to fine-tune the recent Llama-2-7b model on a single Google colab and turn it into a chatbot
We will leverage PEFT library from Hugging Face ecosystem, as well as QLoRA for more memory efficient finetuning
Setup¶
Run the cells below to setup and install the required libraries. For our experiment we will need accelerate
, peft
, transformers
, datasets
and TRL to leverage the recent SFTTrainer
. We will use bitsandbytes
to quantize the base model into 4bit. We will also install einops
as it is a requirement to load Falcon models.
!pip install -q -U trl transformers accelerate git+https://github.com/huggingface/peft.git
!pip install -q datasets bitsandbytes einops wandb
Dataset¶
from datasets import load_dataset
#dataset_name = "timdettmers/openassistant-guanaco" ###Human ,.,,,,,, ###Assistant
dataset_name = 'AlexanderDoria/novel17_test' #french novels
dataset = load_dataset(dataset_name, split="train")
Loading the model¶
import torch
from transformers import AutoModelForCausalLM, AutoTokenizer, BitsAndBytesConfig, AutoTokenizer
model_name = "TinyPixel/Llama-2-7B-bf16-sharded"
bnb_config = BitsAndBytesConfig(
load_in_4bit=True,
bnb_4bit_quant_type="nf4",
bnb_4bit_compute_dtype=torch.float16,
)
model = AutoModelForCausalLM.from_pretrained(
model_name,
quantization_config=bnb_config,
trust_remote_code=True
)
model.config.use_cache = False
Let's also load the tokenizer below
tokenizer = AutoTokenizer.from_pretrained(model_name, trust_remote_code=True)
tokenizer.pad_token = tokenizer.eos_token
from peft import LoraConfig, get_peft_model
lora_alpha = 16
lora_dropout = 0.1
lora_r = 64
peft_config = LoraConfig(
lora_alpha=lora_alpha,
lora_dropout=lora_dropout,
r=lora_r,
bias="none",
task_type="CAUSAL_LM"
)
Loading the trainer¶
Here we will use the SFTTrainer
from TRL library that gives a wrapper around transformers Trainer
to easily fine-tune models on instruction based datasets using PEFT adapters. Let's first load the training arguments below.
from transformers import TrainingArguments
output_dir = "./results"
per_device_train_batch_size = 4
gradient_accumulation_steps = 4
optim = "paged_adamw_32bit"
save_steps = 100
logging_steps = 10
learning_rate = 2e-4
max_grad_norm = 0.3
max_steps = 100
warmup_ratio = 0.03
lr_scheduler_type = "constant"
training_arguments = TrainingArguments(
output_dir=output_dir,
per_device_train_batch_size=per_device_train_batch_size,
gradient_accumulation_steps=gradient_accumulation_steps,
optim=optim,
save_steps=save_steps,
logging_steps=logging_steps,
learning_rate=learning_rate,
fp16=True,
max_grad_norm=max_grad_norm,
max_steps=max_steps,
warmup_ratio=warmup_ratio,
group_by_length=True,
lr_scheduler_type=lr_scheduler_type,
)
Then finally pass everthing to the trainer
from trl import SFTTrainer
max_seq_length = 512
trainer = SFTTrainer(
model=model,
train_dataset=dataset,
peft_config=peft_config,
dataset_text_field="text",
max_seq_length=max_seq_length,
tokenizer=tokenizer,
args=training_arguments,
)
We will also pre-process the model by upcasting the layer norms in float 32 for more stable training
for name, module in trainer.model.named_modules():
if "norm" in name:
module = module.to(torch.float32)
Train the model¶
Now let's train the model! Simply call trainer.train()
trainer.train()
During training, the model should converge nicely as follows:
The SFTTrainer
also takes care of properly saving only the adapters during training instead of saving the entire model.
model_to_save = trainer.model.module if hasattr(trainer.model, 'module') else trainer.model # Take care of distributed/parallel training
model_to_save.save_pretrained("outputs")
lora_config = LoraConfig.from_pretrained('outputs')
model = get_peft_model(model, lora_config)
dataset['text']
text = "Écrire un texte dans un style baroque sur la glace et le feu ### Assistant: Si j'en luis éton"
device = "cuda:0"
inputs = tokenizer(text, return_tensors="pt").to(device)
outputs = model.generate(**inputs, max_new_tokens=50)
print(tokenizer.decode(outputs[0], skip_special_tokens=True))
from huggingface_hub import login
login()
model.push_to_hub("llama2-qlora-finetunined-french")