Distributed training is a crucial aspect of large-scale machine learning models, especially in PyTorch. This guide outlines the best practices for distributed training in PyTorch.
Key Points
- Data Parallelism: Utilize data parallelism to distribute the data across multiple GPUs.
- Model Parallelism: Implement model parallelism when the model is too large to fit on a single GPU.
- Communication Overheads: Minimize communication overheads by using optimized communication libraries.
Step-by-Step Guide
- Setup Distributed Backend: Choose a distributed backend like NCCL or MPI.
- Distributed Data Loading: Use
torch.utils.data.distributed.DistributedSampler
to ensure data is evenly distributed. - Model Initialization: Initialize the model on the first GPU to ensure consistency.
- Backward Propagation: Use
torch.nn.parallel.DistributedDataParallel
for efficient backward propagation.
Tips
- Mixed Precision Training: Utilize mixed precision training to speed up training and reduce memory usage.
- Checkpointing: Regularly save checkpoints to prevent data loss.
Resources
For more detailed information, refer to the PyTorch Distributed Documentation.
Distributed Training