Write your training code:
For this example, the code to run was inspired from an example found here
Note that MASTER_ADDR, MASTER_PORT, WORLD_SIZE, RANK, and LOCAL_RANK are environment variables that will automatically be set.
# Copyright (c) 2017 Facebook, Inc. All rights reserved.
# BSD 3-Clause License
#
# Script adapted from:
# https://github.com/Azure/azureml-examples/blob/main/python-sdk/workflows/train/pytorch/cifar-distributed/src/train.py
# ==============================================================================
import datetime
import torch
import torchvision
import torchvision.transforms as transforms
import torch.nn as nn
import torch.nn.functional as F
import torch.optim as optim
import os, argparse
# define network architecture
class Net(nn.Module):
def __init__(self):
super(Net, self).__init__()
self.conv1 = nn.Conv2d(3, 32, 3)
self.pool = nn.MaxPool2d(2, 2)
self.conv2 = nn.Conv2d(32, 64, 3)
self.conv3 = nn.Conv2d(64, 128, 3)
self.fc1 = nn.Linear(128 * 6 * 6, 120)
self.dropout = nn.Dropout(p=0.2)
self.fc2 = nn.Linear(120, 84)
self.fc3 = nn.Linear(84, 10)
def forward(self, x):
x = F.relu(self.conv1(x))
x = self.pool(F.relu(self.conv2(x)))
x = self.pool(F.relu(self.conv3(x)))
x = x.view(-1, 128 * 6 * 6)
x = self.dropout(F.relu(self.fc1(x)))
x = F.relu(self.fc2(x))
x = self.fc3(x)
return x
# define functions
def train(train_loader, model, criterion, optimizer, epoch, device, print_freq, rank):
running_loss = 0.0
for i, data in enumerate(train_loader, 0):
# get the inputs; data is a list of [inputs, labels]
inputs, labels = data[0].to(device), data[1].to(device)
# zero the parameter gradients
optimizer.zero_grad()
# forward + backward + optimize
outputs = model(inputs)
loss = criterion(outputs, labels)
loss.backward()
optimizer.step()
# print statistics
running_loss += loss.item()
if i % print_freq == 0: # print every print_freq mini-batches
print(
"Rank %d: [%d, %5d] loss: %.3f"
% (rank, epoch + 1, i + 1, running_loss / print_freq)
)
running_loss = 0.0
def evaluate(test_loader, model, device):
classes = (
"plane",
"car",
"bird",
"cat",
"deer",
"dog",
"frog",
"horse",
"ship",
"truck",
)
model.eval()
correct = 0
total = 0
class_correct = list(0.0 for i in range(10))
class_total = list(0.0 for i in range(10))
with torch.no_grad():
for data in test_loader:
images, labels = data[0].to(device), data[1].to(device)
outputs = model(images)
_, predicted = torch.max(outputs.data, 1)
total += labels.size(0)
correct += (predicted == labels).sum().item()
c = (predicted == labels).squeeze()
for i in range(10):
label = labels[i]
class_correct[label] += c[i].item()
class_total[label] += 1
# print total test set accuracy
print(
"Accuracy of the network on the 10000 test images: %d %%"
% (100 * correct / total)
)
# print test accuracy for each of the classes
for i in range(10):
print(
"Accuracy of %5s : %2d %%"
% (classes[i], 100 * class_correct[i] / class_total[i])
)
def main(args):
# get PyTorch environment variables
world_size = int(os.environ["WORLD_SIZE"])
rank = int(os.environ["RANK"])
local_rank = int(os.environ["LOCAL_RANK"])
distributed = world_size > 1
if torch.cuda.is_available():
print("CUDA is available.")
else:
print("CUDA is not available.")
# set device
if distributed:
if torch.cuda.is_available():
device = torch.device("cuda", local_rank)
else:
device = torch.device("cpu")
else:
device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")
# initialize distributed process group using default env:// method
if distributed:
torch.distributed.init_process_group(
backend=args.backend,
timeout=datetime.timedelta(minutes=args.timeout)
)
# define train and test dataset DataLoaders
transform = transforms.Compose(
[transforms.ToTensor(), transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5))]
)
train_set = torchvision.datasets.CIFAR10(
root=args.data_dir, train=True, download=True, transform=transform
)
if distributed:
train_sampler = torch.utils.data.distributed.DistributedSampler(train_set)
else:
train_sampler = None
train_loader = torch.utils.data.DataLoader(
train_set,
batch_size=args.batch_size,
shuffle=(train_sampler is None),
num_workers=args.workers,
sampler=train_sampler,
)
test_set = torchvision.datasets.CIFAR10(
root=args.data_dir, train=False, download=True, transform=transform
)
test_loader = torch.utils.data.DataLoader(
test_set, batch_size=args.batch_size, shuffle=False, num_workers=args.workers
)
model = Net().to(device)
# wrap model with DDP
if distributed:
if torch.cuda.is_available():
model = nn.parallel.DistributedDataParallel(
model, device_ids=[local_rank], output_device=local_rank
)
else:
model = nn.parallel.DistributedDataParallel(model)
# define loss function and optimizer
criterion = nn.CrossEntropyLoss()
optimizer = optim.SGD(
model.parameters(), lr=args.learning_rate, momentum=args.momentum
)
# train the model
for epoch in range(args.epochs):
print("Rank %d: Starting epoch %d" % (rank, epoch))
if distributed:
train_sampler.set_epoch(epoch)
model.train()
train(
train_loader,
model,
criterion,
optimizer,
epoch,
device,
args.print_freq,
rank,
)
print("Rank %d: Finished Training" % (rank))
if not distributed or rank == 0:
os.makedirs(args.output_dir, exist_ok=True)
model_path = os.path.join(args.output_dir, "cifar_net.pt")
torch.save(model.state_dict(), model_path)
# evaluate on full test dataset
evaluate(test_loader, model, device)
# run script
if __name__ == "__main__":
# setup argparse
parser = argparse.ArgumentParser()
parser.add_argument(
"--data-dir", type=str, help="directory containing CIFAR-10 dataset"
)
parser.add_argument("--epochs", default=10, type=int, help="number of epochs")
parser.add_argument(
"--batch-size",
default=16,
type=int,
help="mini batch size for each gpu/process",
)
parser.add_argument(
"--workers",
default=2,
type=int,
help="number of data loading workers for each gpu/process",
)
parser.add_argument(
"--learning-rate", default=0.001, type=float, help="learning rate"
)
parser.add_argument("--momentum", default=0.9, type=float, help="momentum")
parser.add_argument(
"--output-dir", default="outputs", type=str, help="directory to save model to"
)
parser.add_argument(
"--print-freq",
default=200,
type=int,
help="frequency of printing training statistics",
)
parser.add_argument(
"--backend", default="gloo", type=str,
help="distributed communication backend, should be gloo, nccl or mpi"
)
parser.add_argument(
"--timeout", default=30, type=int,
help="timeout in minutes for waiting for the initialization of distributed process group."
)
args = parser.parse_args()
# call main function
main(args)Initialize a distributed-training folder:
At this point you have create a training file (or files) - train.py in the above example. Now running the command below will download the artifacts required for building the docker image. The artifacts will be saved into the oci_dist_training_artifacts/pytorch/v1 directory under your current working directory.
ads opctl distributed-training init --framework pytorch --version v1Containerize your code and build container:
Before you can build the image, you must set the following environment variables:
Specify image name and tag
export IMAGE_NAME=<region.ocir.io/my-tenancy/image-name>
export TAG=latestBuild the container image.
ads opctl distributed-training build-image \
-t $TAG \
-reg $IMAGE_NAME \
-df oci_dist_training_artifacts/pytorch/v1/DockerfileThe code is assumed to be in the current working directory. To override the source code directory, use the -s flag and specify the code dir. This folder should be within the current working directory.
ads opctl distributed-training build-image \
-t $TAG \
-reg $IMAGE_NAME \
-df oci_dist_training_artifacts/horovod/v1/oci_dist_training_artifacts/pytorch/v1/Dockerfile
-s <code_dir>If you are behind proxy, ads opctl will automatically use your proxy settings (defined via no_proxy, http_proxy and https_proxy).
Define your workload yaml:
The yaml file is a declarative way to express the workload. Following is the YAML for running the example code, you will need to replace the values in the spec sections for your project:
infrastructurecontainsspecfor OCI Data Science Jobs. Here you need to specify a subnet that allows communications between nodes. TheVM.GPU2.1shape is used in this example.clustercontainsspecfor the image you built and a working directory on OCI object storage, which will be used by job runs to shared internal configurations. Environment variables specified in thecluster.spec.configwill be available in all nodes. Here theNCCL_ASYNC_ERROR_HANDLINGis used to enable the timeout for NCCL backend. The job runs will be terminated if the nodes failed to connect to each other in certain minutes as specified in your training code when callinginit_process_group().runtimecontainsspecfor the name of your training script, and the command line arguments for running the script. Here thencclbackend is used for communications between GPUs. For CPU training, you can use thegloobackend. Thetimeoutargument specify the maximum minutes for the nodes to wait when callinginit_process_group(). This is useful for preventing the job runs to wait forever in case of node failure.
kind: distributed
apiVersion: v1.0
spec:
infrastructure:
kind: infrastructure
type: dataScienceJob
apiVersion: v1.0
spec:
projectId: oci.xxxx.<project_ocid>
compartmentId: oci.xxxx.<compartment_ocid>
displayName: PyTorch-Distributed
logGroupId: oci.xxxx.<log_group_ocid>
logId: oci.xxx.<log_ocid>
subnetId: oci.xxxx.<subnet-ocid>
shapeName: VM.GPU2.1
blockStorageSize: 50
cluster:
kind: pytorch
apiVersion: v1.0
spec:
image: <region.ocir.io/my-tenancy/image-name>
workDir: "oci://my-bucket@my-namespace/pytorch/distributed"
config:
env:
- name: NCCL_ASYNC_ERROR_HANDLING
value: '1'
main:
name: PyTorch-Distributed-main
replicas: 1
worker:
name: PyTorch-Distributed-worker
replicas: 3
runtime:
kind: python
apiVersion: v1.0
spec:
entryPoint: "train.py"
args:
- --data-dir
- /home/datascience/data
- --output-dir
- /home/datascience/outputs
- --backend
- gloo
- --timeout
- 5Use ads opctl to create the cluster infrastructure and dry-run the workload:
ads opctl run -f train.yaml --dry-runthe output from the dry run will show all the actions and infrastructure configuration.
Use ads opctl to create the cluster infrastructure and run the workload:
model_path = os.path.join(os.environ.get("OCI__SYNC_DIR"),"model.pt")
torch.save(model, model_path)Profiling
You may want to profile your training setup for optimization/performance tuning. Profiling typically provides a detailed analysis of cpu utilization, gpu utilization, top cuda kernels, top operators etc. You can choose to profile your training setup using the native Pytorch profiler or using a third party profiler such as Nvidia Nsights.
Profiling using Pytorch Profiler
Pytorch Profiler is a native offering from Pytorch for Pytorch performance profiling. Profiling is invoked using code instrumentation using the api torch.profiler.profile.
Refer this link for changes that you need to do in your training script for instrumentation. You should choose the OCI__SYNC_DIR directory to save the profiling logs. For example:
prof = torch.profiler.profile(activities=[torch.profiler.ProfilerActivity.CPU,torch.profiler.ProfilerActivity.CUDA],
schedule=torch.profiler.schedule(
wait=1,
warmup=1,
active=3,
repeat=1),
on_trace_ready=torch.profiler.tensorboard_trace_handler(os.environ.get("OCI__SYNC_DIR") + "/logs"),
with_stack=False)
prof.start()
# training code
prof.end()Also, the sync feature SYNC_ARTIFACTS should be enabled '1' to sync the profiling logs to the configured object storage.
You would also need to install the Pytorch Tensorboard Plugin.
pip install torch-tb-profilerThereafter, use Tensorboard to view logs. Refer the Tensorboard setup <../../tensorboard/tensorboard> for set-up on your computer.