CODEWITHSUNDEEP
pythonpytorch
Suraj Ghale
Suraj Ghale

Reputation: 301

ValueError: Error initializing torch.distributed using env:// rendezvous: environment variable MASTER_ADDR expected, but not set

I am not able to initialize the group process in PyTorch for BERT model I had tried to initialize using following code:

import torch
import datetime

torch.distributed.init_process_group(
    backend='nccl',
    init_method='env://',
    timeout=datetime.timedelta(0, 1800),
    world_size=0,
    rank=0,
    store=None,
    group_name=''
)

and tried to access the get_world_size() function:

num_train_optimization_steps = num_train_optimization_steps // torch.distributed.get_world_size()

full code:

train_examples = None
    num_train_optimization_steps = None
    if do_train:
        train_examples = processor.get_train_examples(data_dir)
        num_train_optimization_steps = int(
            len(train_examples) / train_batch_size / gradient_accumulation_steps) * num_train_epochs
        if local_rank != -1:
            import datetime
            torch.distributed.init_process_group(backend='nccl',init_method='env://', timeout=datetime.timedelta(0, 1800), world_size=0, rank=0, store=None, group_name='')
            num_train_optimization_steps = num_train_optimization_steps // torch.distributed.get_world_size()
            print(num_train_optimization_steps)

Upvotes: 14

Views: 47187

Answers (4)

Nikhil Verma
Nikhil Verma

Reputation: 81

How to do the setup for distributed training is defined here by PyTorch -> https://huggingface.co/blog/pytorch-ddp-accelerate-transformers

But you could also do the setting up by adding following lines to your code

import os
os.environ['MASTER_ADDR'] = 'localhost'
os.environ['MASTER_PORT'] = '12355'
os.environ["CUDA_VISIBLE_DEVICES"] = "0,1,2,3"
dist.init_process_group(backend='nccl', init_method='env://', rank = torch.cuda.device_count(), world_size = 1)

Upvotes: 4

Baragorn
Baragorn

Reputation: 146

you can also add these lines to your script if you want to run the script in native python (helpful for debugging purposes)

os.environ['MASTER_ADDR'] = 'localhost'
os.environ['MASTER_PORT'] = '12355'

Upvotes: 0

mah_mpc
mah_mpc

Reputation: 101

Just an update, instead of running:

$ python -m torch.distributed.launch --use_env train_script.py

You now only need to run:

$ torchrun train_script.py

As indicated here.

Upvotes: 10

Dandelion
Dandelion

Reputation: 151

I solve the problem by referring https://github.com/NVIDIA/apex/issues/99. Specifically run

python -m torch.distributed.launch xxx.py

Upvotes: 15

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