Migrate advanced-pytorch example to use FDS (#2805)

Co-authored-by: jafermarq <javier@flower.dev>

examples/advanced-pytorch/README.md

@@ -1,6 +1,6 @@
 # Advanced Flower Example (PyTorch)
 
-This example demonstrates an advanced federated learning setup using Flower with PyTorch. It differs from the quickstart example in the following ways:
+This example demonstrates an advanced federated learning setup using Flower with PyTorch. This example uses [Flower Datasets](https://flower.dev/docs/datasets/) and it differs from the quickstart example in the following ways:
 
 - 10 clients (instead of just 2)
 - Each client holds a local dataset of 5000 training examples and 1000 test examples (note that using the `run.sh` script will only select 10 data samples by default, as the `--toy` argument is set).
@@ -59,12 +59,13 @@ pip install -r requirements.txt
 
 The included `run.sh` will start the Flower server (using `server.py`),
 sleep for 2 seconds to ensure that the server is up, and then start 10 Flower clients (using `client.py`) with only a small subset of the data (in order to run on any machine),
-but this can be changed by removing the `--toy True` argument in the script. You can simply start everything in a terminal as follows:
+but this can be changed by removing the `--toy` argument in the script. You can simply start everything in a terminal as follows:
 
 ```shell
-poetry run ./run.sh
+# After activating your environment
+./run.sh
 ```
 
 The `run.sh` script starts processes in the background so that you don't have to open eleven terminal windows. If you experiment with the code example and something goes wrong, simply using `CTRL + C` on Linux (or `CMD + C` on macOS) wouldn't normally kill all these processes, which is why the script ends with `trap "trap - SIGTERM && kill -- -$$" SIGINT SIGTERM EXIT` and `wait`. This simply allows you to stop the experiment using `CTRL + C` (or `CMD + C`). If you change the script and anything goes wrong you can still use `killall python` (or `killall python3`) to kill all background processes (or a more specific command if you have other Python processes running that you don't want to kill).
 
-You can also manually run `poetry run python3 server.py` and `poetry run python3 client.py` for as many clients as you want but you have to make sure that each command is ran in a different terminal window (or a different computer on the network).
+You can also manually run `python3 server.py` and `python3 client.py --client-id <ID>` for as many clients as you want but you have to make sure that each command is run in a different terminal window (or a different computer on the network).

examples/advanced-pytorch/client.py

@@ -6,16 +6,17 @@
 import argparse
 from collections import OrderedDict
 import warnings
+import datasets
 
 warnings.filterwarnings("ignore")
 
 
 class CifarClient(fl.client.NumPyClient):
     def __init__(
         self,
-        trainset: torchvision.datasets,
-        testset: torchvision.datasets,
-        device: str,
+        trainset: datasets.Dataset,
+        testset: datasets.Dataset,
+        device: torch.device,
         validation_split: int = 0.1,
     ):
         self.device = device
@@ -41,17 +42,14 @@ def fit(self, parameters, config):
         batch_size: int = config["batch_size"]
         epochs: int = config["local_epochs"]
 
-        n_valset = int(len(self.trainset) * self.validation_split)
+        train_valid = self.trainset.train_test_split(self.validation_split)
+        trainset = train_valid["train"]
+        valset = train_valid["test"]
 
-        valset = torch.utils.data.Subset(self.trainset, range(0, n_valset))
-        trainset = torch.utils.data.Subset(
-            self.trainset, range(n_valset, len(self.trainset))
-        )
+        train_loader = DataLoader(trainset, batch_size=batch_size, shuffle=True)
+        val_loader = DataLoader(valset, batch_size=batch_size)
 
-        trainLoader = DataLoader(trainset, batch_size=batch_size, shuffle=True)
-        valLoader = DataLoader(valset, batch_size=batch_size)
-
-        results = utils.train(model, trainLoader, valLoader, epochs, self.device)
+        results = utils.train(model, train_loader, val_loader, epochs, self.device)
 
         parameters_prime = utils.get_model_params(model)
         num_examples_train = len(trainset)
@@ -73,13 +71,13 @@ def evaluate(self, parameters, config):
         return float(loss), len(self.testset), {"accuracy": float(accuracy)}
 
 
-def client_dry_run(device: str = "cpu"):
+def client_dry_run(device: torch.device = "cpu"):
     """Weak tests to check whether all client methods are working as expected."""
 
     model = utils.load_efficientnet(classes=10)
     trainset, testset = utils.load_partition(0)
-    trainset = torch.utils.data.Subset(trainset, range(10))
-    testset = torch.utils.data.Subset(testset, range(10))
+    trainset = trainset.select(range(10))
+    testset = testset.select(range(10))
     client = CifarClient(trainset, testset, device)
     client.fit(
         utils.get_model_params(model),
@@ -102,7 +100,7 @@ def main() -> None:
         help="Do a dry-run to check the client",
     )
     parser.add_argument(
-        "--partition",
+        "--client-id",
         type=int,
         default=0,
         choices=range(0, 10),
@@ -112,9 +110,7 @@ def main() -> None:
     )
     parser.add_argument(
         "--toy",
-        type=bool,
-        default=False,
-        required=False,
+        action='store_true',
         help="Set to true to quicky run the client using only 10 datasamples. \
         Useful for testing purposes. Default: False",
     )
@@ -136,12 +132,11 @@ def main() -> None:
         client_dry_run(device)
     else:
         # Load a subset of CIFAR-10 to simulate the local data partition
-        trainset, testset = utils.load_partition(args.partition)
+        trainset, testset = utils.load_partition(args.client_id)
 
         if args.toy:
-            trainset = torch.utils.data.Subset(trainset, range(10))
-            testset = torch.utils.data.Subset(testset, range(10))
-
+            trainset = trainset.select(range(10))
+            testset = testset.select(range(10))
         # Start Flower client
         client = CifarClient(trainset, testset, device)
 

examples/advanced-pytorch/pyproject.toml

@@ -14,6 +14,7 @@ authors = [
 [tool.poetry.dependencies]
 python = ">=3.8,<3.11"
 flwr = ">=1.0,<2.0"
+flwr-datasets = { extras = ["vision"], version = ">=0.0.2,<1.0.0" }
 torch = "1.13.1"
 torchvision = "0.14.1"
 validators = "0.18.2"

examples/advanced-pytorch/requirements.txt

@@ -1,4 +1,5 @@
 flwr>=1.0, <2.0
+flwr-datasets[vision]>=0.0.2, <1.0.0
 torch==1.13.1
 torchvision==0.14.1
 validators==0.18.2

examples/advanced-pytorch/run.sh

@@ -2,20 +2,17 @@
 set -e
 cd "$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"/
 
-# Download the CIFAR-10 dataset
-python -c "from torchvision.datasets import CIFAR10; CIFAR10('./dataset', download=True)"
-
 # Download the EfficientNetB0 model
 python -c "import torch; torch.hub.load( \
         'NVIDIA/DeepLearningExamples:torchhub', \
         'nvidia_efficientnet_b0', pretrained=True)"
 
-python server.py &
-sleep 3  # Sleep for 3s to give the server enough time to start
+python server.py --toy  &
+sleep 10  # Sleep for 10s to give the server enough time to start and dowload the dataset
 
 for i in `seq 0 9`; do
     echo "Starting client $i"
-    python client.py --partition=${i} --toy True &
+    python client.py --client-id=${i} --toy &
 done
 
 # Enable CTRL+C to stop all background processes

examples/advanced-pytorch/server.py

@@ -10,6 +10,8 @@
 
 import warnings
 
+from flwr_datasets import FederatedDataset
+
 warnings.filterwarnings("ignore")
 
 
@@ -39,18 +41,13 @@ def evaluate_config(server_round: int):
 def get_evaluate_fn(model: torch.nn.Module, toy: bool):
     """Return an evaluation function for server-side evaluation."""
 
-    # Load data and model here to avoid the overhead of doing it in `evaluate` itself
-    trainset, _, _ = utils.load_data()
-
-    n_train = len(trainset)
+    # Load data here to avoid the overhead of doing it in `evaluate` itself
+    centralized_data = utils.load_centralized_data()
     if toy:
         # use only 10 samples as validation set
-        valset = torch.utils.data.Subset(trainset, range(n_train - 10, n_train))
-    else:
-        # Use the last 5k training examples as a validation set
-        valset = torch.utils.data.Subset(trainset, range(n_train - 5000, n_train))
+        centralized_data = centralized_data.select(range(10))
 
-    valLoader = DataLoader(valset, batch_size=16)
+    val_loader = DataLoader(centralized_data, batch_size=16)
 
     # The `evaluate` function will be called after every round
     def evaluate(
@@ -63,7 +60,7 @@ def evaluate(
         state_dict = OrderedDict({k: torch.tensor(v) for k, v in params_dict})
         model.load_state_dict(state_dict, strict=True)
 
-        loss, accuracy = utils.test(model, valLoader)
+        loss, accuracy = utils.test(model, val_loader)
         return loss, {"accuracy": accuracy}
 
     return evaluate
@@ -79,9 +76,7 @@ def main():
     parser = argparse.ArgumentParser(description="Flower")
     parser.add_argument(
         "--toy",
-        type=bool,
-        default=False,
-        required=False,
+        action='store_true',
         help="Set to true to use only 10 datasamples for validation. \
             Useful for testing purposes. Default: False",
     )

examples/advanced-pytorch/utils.py

@@ -1,49 +1,45 @@
 import torch
-import torchvision.transforms as transforms
-from torchvision.datasets import CIFAR10
+from torchvision.transforms import Compose, ToTensor, Normalize, Resize, CenterCrop
+from torch.utils.data import DataLoader
 
 import warnings
 
-warnings.filterwarnings("ignore")
-
-# DEVICE = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")
+from flwr_datasets import FederatedDataset
 
+warnings.filterwarnings("ignore")
 
-def load_data():
-    """Load CIFAR-10 (training and test set)."""
-    transform = transforms.Compose(
-        [
-            transforms.Resize(256),
-            transforms.CenterCrop(224),
-            transforms.ToTensor(),
-            transforms.Normalize(mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225]),
-        ]
-    )
 
-    trainset = CIFAR10("./dataset", train=True, download=True, transform=transform)
-    testset = CIFAR10("./dataset", train=False, download=True, transform=transform)
+def load_partition(node_id, toy: bool = False):
+    """Load partition CIFAR10 data."""
+    fds = FederatedDataset(dataset="cifar10", partitioners={"train": 10})
+    partition = fds.load_partition(node_id)
+    # Divide data on each node: 80% train, 20% test
+    partition_train_test = partition.train_test_split(test_size=0.2)
+    partition_train_test = partition_train_test.with_transform(apply_transforms)
+    return partition_train_test["train"], partition_train_test["test"]
 
-    num_examples = {"trainset": len(trainset), "testset": len(testset)}
-    return trainset, testset, num_examples
 
+def load_centralized_data():
+    fds = FederatedDataset(dataset="cifar10", partitioners={"train": 10})
+    centralized_data = fds.load_full("test")
+    centralized_data = centralized_data.with_transform(apply_transforms)
+    return centralized_data
 
-def load_partition(idx: int):
-    """Load 1/10th of the training and test data to simulate a partition."""
-    assert idx in range(10)
-    trainset, testset, num_examples = load_data()
-    n_train = int(num_examples["trainset"] / 10)
-    n_test = int(num_examples["testset"] / 10)
 
-    train_parition = torch.utils.data.Subset(
-        trainset, range(idx * n_train, (idx + 1) * n_train)
-    )
-    test_parition = torch.utils.data.Subset(
-        testset, range(idx * n_test, (idx + 1) * n_test)
-    )
-    return (train_parition, test_parition)
+def apply_transforms(batch):
+    """Apply transforms to the partition from FederatedDataset."""
+    pytorch_transforms = Compose([
+        Resize(256),
+        CenterCrop(224),
+        ToTensor(),
+        Normalize(mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225]),
+    ])
+    batch["img"] = [pytorch_transforms(img) for img in batch["img"]]
+    return batch
 
 
-def train(net, trainloader, valloader, epochs, device: str = "cpu"):
+def train(net, trainloader, valloader, epochs,
+          device: torch.device = torch.device("cpu")):
     """Train the network on the training set."""
     print("Starting training...")
     net.to(device)  # move model to GPU if available
@@ -53,7 +49,8 @@ def train(net, trainloader, valloader, epochs, device: str = "cpu"):
     )
     net.train()
     for _ in range(epochs):
-        for images, labels in trainloader:
+        for batch in trainloader:
+            images, labels = batch["img"], batch["label"]
             images, labels = images.to(device), labels.to(device)
             optimizer.zero_grad()
             loss = criterion(net(images), labels)
@@ -74,15 +71,17 @@ def train(net, trainloader, valloader, epochs, device: str = "cpu"):
     return results
 
 
-def test(net, testloader, steps: int = None, device: str = "cpu"):
+def test(net, testloader, steps: int = None,
+         device: torch.device = torch.device("cpu")):
     """Validate the network on the entire test set."""
     print("Starting evalutation...")
     net.to(device)  # move model to GPU if available
     criterion = torch.nn.CrossEntropyLoss()
     correct, loss = 0, 0.0
     net.eval()
     with torch.no_grad():
-        for batch_idx, (images, labels) in enumerate(testloader):
+        for batch_idx, batch in enumerate(testloader):
+            images, labels = batch["img"], batch["label"]
             images, labels = images.to(device), labels.to(device)
             outputs = net(images)
             loss += criterion(outputs, labels).item()
@@ -109,12 +108,14 @@ def load_efficientnet(entrypoint: str = "nvidia_efficientnet_b0", classes: int =
         entrypoint: EfficientNet model to download.
                     For supported entrypoints, please refer
                     https://pytorch.org/hub/nvidia_deeplearningexamples_efficientnet/
-        classes: Number of classes in final classifying layer. Leave as None to get the downloaded
+        classes: Number of classes in final classifying layer. Leave as None to get
+        the downloaded
                  model untouched.
     Returns:
         EfficientNet Model
 
-    Note: One alternative implementation can be found at https://github.com/lukemelas/EfficientNet-PyTorch
+    Note: One alternative implementation can be found at
+    https://github.com/lukemelas/EfficientNet-PyTorch
     """
     efficientnet = torch.hub.load(
         "NVIDIA/DeepLearningExamples:torchhub", entrypoint, pretrained=True