Enable Support for Multi-GPU Training (#517)

* Add `pickle_protocol` to `DataConfig` for passing
it down to `torch.save()` when caching datasets to disk

* Save the index of the original dataframe in `TabularDataset`
so that it can be restored when accessing `TabularDataset.data`

* Add `sync_dist=True` to all calls to self.log() in
`validation_step()` and `test_step()` to distributed training

* Fix `TrainerConfig.precision` to be a string and
remove integer choices. Add a pointer to docs with
possible options

* Add `sync_dist` to SSL Models

* Address `PerformanceWarning` related to `frame.insert()`

* Only load best checkpoint on rank zero in distributed
training

* if logging with wandb, `unwatch` the model after training

* address `FutureWarning` re inplace=True

src/pytorch_tabular/categorical_encoders.py

@@ -68,7 +68,7 @@ def transform(self, X):
             X_encoded[col] = X_encoded[col].fillna(NAN_CATEGORY).map(mapping["value"])
 
             if self.handle_unseen == "impute":
-                X_encoded[col].fillna(self._imputed, inplace=True)
+                X_encoded[col] = X_encoded[col].fillna(self._imputed)
             elif self.handle_unseen == "error":
                 if np.unique(X_encoded[col]).shape[0] > mapping.shape[0]:
                     raise ValueError(f"Unseen categories found in `{col}` column.")

src/pytorch_tabular/config/config.py

@@ -96,6 +96,8 @@ class DataConfig:
         handle_missing_values (bool): Whether to handle missing values in categorical columns as
                 unknown
 
+        pickle_protocol (int): pickle protocol version passed to `torch.save` for dataset caching to disk
+
         dataloader_kwargs (Dict[str, Any]): Additional kwargs to be passed to PyTorch DataLoader. See
                 https://pytorch.org/docs/stable/data.html#torch.utils.data.DataLoader
 
@@ -179,6 +181,11 @@ class DataConfig:
         metadata={"help": "Whether or not to handle missing values in categorical columns as unknown"},
     )
 
+    pickle_protocol: int = field(
+        default=2,
+        metadata={"help": "pickle protocol version passed to `torch.save` for dataset caching to disk"},
+    )
+
     dataloader_kwargs: Dict[str, Any] = field(
         default_factory=dict,
         metadata={"help": "Additional kwargs to be passed to PyTorch DataLoader."},
@@ -351,8 +358,8 @@ class TrainerConfig:
 
         progress_bar (str): Progress bar type. Can be one of: `none`, `simple`, `rich`. Defaults to `rich`.
 
-        precision (int): Precision of the model. Can be one of: `32`, `16`, `64`. Defaults to `32`..
-                Choices are: [`32`,`16`,`64`].
+        precision (str): Precision of the model. Defaults to `32`. See
+                https://lightning.ai/docs/pytorch/stable/common/trainer.html#precision
 
         seed (int): Seed for random number generators. Defaults to 42
 
@@ -536,11 +543,10 @@ class TrainerConfig:
         default="rich",
         metadata={"help": "Progress bar type. Can be one of: `none`, `simple`, `rich`. Defaults to `rich`."},
     )
-    precision: int = field(
-        default=32,
+    precision: str = field(
+        default="32",
         metadata={
-            "help": "Precision of the model. Can be one of: `32`, `16`, `64`. Defaults to `32`.",
-            "choices": [32, 16, 64],
+            "help": "Precision of the model. Defaults to `32`.",
         },
     )
     seed: int = field(

src/pytorch_tabular/feature_extractor.py

@@ -79,15 +79,21 @@ def transform(self, X: pd.DataFrame, y=None) -> pd.DataFrame:
                 if k in ret_value.keys():
                     logits_predictions[k].append(ret_value[k].detach().cpu())
 
+        logits_dfs = []
         for k, v in logits_predictions.items():
             v = torch.cat(v, dim=0).numpy()
             if v.ndim == 1:
                 v = v.reshape(-1, 1)
-            for i in range(v.shape[-1]):
-                if v.shape[-1] > 1:
-                    X_encoded[f"{k}_{i}"] = v[:, i]
-                else:
-                    X_encoded[f"{k}"] = v[:, i]
+            if v.shape[-1] > 1:
+                temp_df = pd.DataFrame({f"{k}_{i}": v[:, i] for i in range(v.shape[-1])})
+            else:
+                temp_df = pd.DataFrame({f"{k}": v[:, 0]})
+
+            # Append the temp DataFrame to the list
+            logits_dfs.append(temp_df)
+
+        preds = pd.concat(logits_dfs, axis=1)
+        X_encoded = pd.concat([X_encoded, preds], axis=1)
 
         if self.drop_original:
             X_encoded.drop(columns=orig_features, inplace=True)

src/pytorch_tabular/models/base_model.py

@@ -244,13 +244,14 @@ def _setup_metrics(self):
         else:
             self.metrics = self.custom_metrics
 
-    def calculate_loss(self, output: Dict, y: torch.Tensor, tag: str) -> torch.Tensor:
+    def calculate_loss(self, output: Dict, y: torch.Tensor, tag: str, sync_dist: bool = False) -> torch.Tensor:
         """Calculates the loss for the model.
 
         Args:
             output (Dict): The output dictionary from the model
             y (torch.Tensor): The target tensor
             tag (str): The tag to use for logging
+            sync_dist (bool): enable distributed sync of logs
 
         Returns:
             torch.Tensor: The loss value
@@ -270,6 +271,7 @@ def calculate_loss(self, output: Dict, y: torch.Tensor, tag: str) -> torch.Tenso
                     on_step=False,
                     logger=True,
                     prog_bar=False,
+                    sync_dist=sync_dist,
                 )
         if self.hparams.task == "regression":
             computed_loss = reg_loss
@@ -284,6 +286,7 @@ def calculate_loss(self, output: Dict, y: torch.Tensor, tag: str) -> torch.Tenso
                         on_step=False,
                         logger=True,
                         prog_bar=False,
+                        sync_dist=sync_dist,
                     )
         else:
             # TODO loss fails with batch size of 1?
@@ -301,6 +304,7 @@ def calculate_loss(self, output: Dict, y: torch.Tensor, tag: str) -> torch.Tenso
                         on_step=False,
                         logger=True,
                         prog_bar=False,
+                        sync_dist=sync_dist,
                     )
                 start_index = end_index
         self.log(
@@ -311,10 +315,13 @@ def calculate_loss(self, output: Dict, y: torch.Tensor, tag: str) -> torch.Tenso
             # on_step=False,
             logger=True,
             prog_bar=True,
+            sync_dist=sync_dist,
         )
         return computed_loss
 
-    def calculate_metrics(self, y: torch.Tensor, y_hat: torch.Tensor, tag: str) -> List[torch.Tensor]:
+    def calculate_metrics(
+        self, y: torch.Tensor, y_hat: torch.Tensor, tag: str, sync_dist: bool = False
+    ) -> List[torch.Tensor]:
         """Calculates the metrics for the model.
 
         Args:
@@ -324,6 +331,8 @@ def calculate_metrics(self, y: torch.Tensor, y_hat: torch.Tensor, tag: str) -> L
 
             tag (str): The tag to use for logging
 
+            sync_dist (bool): enable distributed sync of logs
+
         Returns:
             List[torch.Tensor]: The list of metric values
 
@@ -356,6 +365,7 @@ def calculate_metrics(self, y: torch.Tensor, y_hat: torch.Tensor, tag: str) -> L
                             on_step=False,
                             logger=True,
                             prog_bar=False,
+                            sync_dist=sync_dist,
                         )
                     _metrics.append(_metric)
                 avg_metric = torch.stack(_metrics, dim=0).sum()
@@ -379,6 +389,7 @@ def calculate_metrics(self, y: torch.Tensor, y_hat: torch.Tensor, tag: str) -> L
                             on_step=False,
                             logger=True,
                             prog_bar=False,
+                            sync_dist=sync_dist,
                         )
                     _metrics.append(_metric)
                     start_index = end_index
@@ -391,6 +402,7 @@ def calculate_metrics(self, y: torch.Tensor, y_hat: torch.Tensor, tag: str) -> L
                 on_step=False,
                 logger=True,
                 prog_bar=True,
+                sync_dist=sync_dist,
             )
         return metrics
 
@@ -523,19 +535,19 @@ def validation_step(self, batch, batch_idx):
             # fetched from the batch
             y = batch["target"] if y is None else y
             y_hat = output["logits"]
-            self.calculate_loss(output, y, tag="valid")
-            self.calculate_metrics(y, y_hat, tag="valid")
+            self.calculate_loss(output, y, tag="valid", sync_dist=True)
+            self.calculate_metrics(y, y_hat, tag="valid", sync_dist=True)
         return y_hat, y
 
     def test_step(self, batch, batch_idx):
         with torch.no_grad():
             output, y = self.forward_pass(batch)
-            # y is not None for SSL task.Rest of the tasks target is
+            # y is not None for SSL task. Rest of the tasks target is
             # fetched from the batch
             y = batch["target"] if y is None else y
             y_hat = output["logits"]
-            self.calculate_loss(output, y, tag="test")
-            self.calculate_metrics(y, y_hat, tag="test")
+            self.calculate_loss(output, y, tag="test", sync_dist=True)
+            self.calculate_metrics(y, y_hat, tag="test", sync_dist=True)
         return y_hat, y
 
     def configure_optimizers(self):

src/pytorch_tabular/ssl_models/base_model.py

@@ -136,11 +136,11 @@ def _setup_metrics(self):
         pass
 
     @abstractmethod
-    def calculate_loss(self, output, tag):
+    def calculate_loss(self, output, tag, sync_dist):
         pass
 
     @abstractmethod
-    def calculate_metrics(self, output, tag):
+    def calculate_metrics(self, output, tag, sync_dist):
         pass
 
     @abstractmethod
@@ -167,15 +167,15 @@ def training_step(self, batch, batch_idx):
     def validation_step(self, batch, batch_idx):
         with torch.no_grad():
             output = self.forward(batch)
-            self.calculate_loss(output, tag="valid")
-            self.calculate_metrics(output, tag="valid")
+            self.calculate_loss(output, tag="valid", sync_dist=True)
+            self.calculate_metrics(output, tag="valid", sync_dist=True)
         return output
 
     def test_step(self, batch, batch_idx):
         with torch.no_grad():
             output = self.forward(batch)
-            self.calculate_loss(output, tag="test")
-            self.calculate_metrics(output, tag="test")
+            self.calculate_loss(output, tag="test", sync_dist=True)
+            self.calculate_metrics(output, tag="test", sync_dist=True)
         return output
 
     def on_validation_epoch_end(self) -> None:

src/pytorch_tabular/ssl_models/dae/dae.py

@@ -200,7 +200,7 @@ def forward(self, x: Dict):
             else:
                 return z.features
 
-    def calculate_loss(self, output, tag):
+    def calculate_loss(self, output, tag, sync_dist=False):
         total_loss = 0
         for type_, out in output.items():
             if type_ == "categorical":
@@ -220,6 +220,7 @@ def calculate_loss(self, output, tag):
                 on_step=False,
                 logger=True,
                 prog_bar=False,
+                sync_dist=sync_dist,
             )
             total_loss += loss
         self.log(
@@ -230,10 +231,11 @@ def calculate_loss(self, output, tag):
             # on_step=False,
             logger=True,
             prog_bar=True,
+            sync_dist=sync_dist,
         )
         return total_loss
 
-    def calculate_metrics(self, output, tag):
+    def calculate_metrics(self, output, tag, sync_dist=False):
         pass
 
     def featurize(self, x: Dict):

src/pytorch_tabular/tabular_datamodule.py

@@ -61,6 +61,7 @@ def __init__(
         self.task = task
         self.n = data.shape[0]
         self.target = target
+        self.index = data.index
         if target:
             self.y = data[target].astype(np.float32).values
             if isinstance(target, str):
@@ -87,11 +88,12 @@ def data(self):
             data = pd.DataFrame(
                 np.concatenate([self.categorical_X, self.continuous_X], axis=1),
                 columns=self.categorical_cols + self.continuous_cols,
+                index=self.index,
             )
         elif self.continuous_cols:
-            data = pd.DataFrame(self.continuous_X, columns=self.continuous_cols)
+            data = pd.DataFrame(self.continuous_X, columns=self.continuous_cols, index=self.index)
         elif self.categorical_cols:
-            data = pd.DataFrame(self.categorical_X, columns=self.categorical_cols)
+            data = pd.DataFrame(self.categorical_X, columns=self.categorical_cols, index=self.index)
         else:
             data = pd.DataFrame()
         for i, t in enumerate(self.target):
@@ -474,6 +476,7 @@ def _cache_dataset(self):
             target=self.target,
         )
         self.train = None
+
         validation_dataset = TabularDataset(
             task=self.config.task,
             data=self.validation,
@@ -484,8 +487,10 @@ def _cache_dataset(self):
         self.validation = None
 
         if self.cache_mode is self.CACHE_MODES.DISK:
-            torch.save(train_dataset, self.cache_dir / "train_dataset")
-            torch.save(validation_dataset, self.cache_dir / "validation_dataset")
+            torch.save(train_dataset, self.cache_dir / "train_dataset", pickle_protocol=self.config.pickle_protocol)
+            torch.save(
+                validation_dataset, self.cache_dir / "validation_dataset", pickle_protocol=self.config.pickle_protocol
+            )
         elif self.cache_mode is self.CACHE_MODES.MEMORY:
             self.train_dataset = train_dataset
             self.validation_dataset = validation_dataset

src/pytorch_tabular/tabular_model.py

@@ -31,6 +31,7 @@
 )
 from pytorch_lightning.tuner.tuning import Tuner
 from pytorch_lightning.utilities.model_summary import summarize
+from pytorch_lightning.utilities.rank_zero import rank_zero_only
 from rich import print as rich_print
 from rich.pretty import pprint
 from sklearn.base import TransformerMixin
@@ -685,6 +686,8 @@ def train(
                 "/n" + "Original Error: " + oom_handler.oom_msg
             )
         self._is_fitted = True
+        if self.track_experiment and self.config.log_target == "wandb":
+            self.logger.experiment.unwatch(self.model)
         if self.verbose:
             logger.info("Training the model completed")
         if self.config.load_best:
@@ -1522,6 +1525,7 @@ def add_noise(module, input, output):
             )
         return pred_df
 
+    @rank_zero_only
     def load_best_model(self) -> None:
         """Loads the best model after training is done."""
         if self.trainer.checkpoint_callback is not None: