fix: use global rank for dataset download guard in container backend notebook (#3418)

Signed-off-by: Fiona-Waters <fiwaters6@gmail.com>

Author: Fiona-Waters

examples/local/local-container-mnist.ipynb

@@ -108,16 +108,12 @@
     "    model = nn.parallel.DistributedDataParallel(model)\n",
     "    optimizer = optim.SGD(model.parameters(), lr=0.01, momentum=0.5)\n",
     "\n",
-    "    # Download FashionMNIST dataset only on local_rank=0 process.\n",
-    "    if local_rank == 0:\n",
-    "        dataset = datasets.FashionMNIST(\n",
+    "    # Download FashionMNIST dataset only on global rank 0 process.\n",
+    "    if dist.get_rank() == 0:\n",
+    "        datasets.FashionMNIST(\n",
     "            \"./data\",\n",
     "            train=True,\n",
     "            download=True,\n",
-    "            transform=transforms.Compose([\n",
-    "                transforms.ToTensor(),\n",
-    "                transforms.Normalize((0.1307,), (0.3081,)),\n",
-    "            ]),\n",
     "        )\n",
     "    dist.barrier()\n",
     "    dataset = datasets.FashionMNIST(\n",
@@ -127,7 +123,7 @@
     "        transform=transforms.Compose([transforms.ToTensor()]),\n",
     "    )\n",
     "\n",
-    "    # Shard the dataset accross workers.\n",
+    "    # Shard the dataset across workers.\n",
     "    train_loader = DataLoader(\n",
     "        dataset,\n",
     "        batch_size=100,\n",
@@ -374,7 +370,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3 (ipykernel)",
+   "display_name": "Python 3",
    "language": "python",
    "name": "python3"
   },
@@ -388,7 +384,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.11.13"
+   "version": "3.13.7"
   }
  },
  "nbformat": 4,