[pyspark] Use quantile dmatrix.

doc/parameter.rst

@@ -349,7 +349,7 @@ Specify the learning task and the corresponding learning objective. The objectiv
   - ``reg:squaredlogerror``: regression with squared log loss :math:`\frac{1}{2}[log(pred + 1) - log(label + 1)]^2`.  All input labels are required to be greater than -1.  Also, see metric ``rmsle`` for possible issue  with this objective.
   - ``reg:logistic``: logistic regression.
   - ``reg:pseudohubererror``: regression with Pseudo Huber loss, a twice differentiable alternative to absolute loss.
-  - ``reg:absoluteerror``: Regression with L1 error. When tree model is used, leaf value is refreshed after tree construction.
+  - ``reg:absoluteerror``: Regression with L1 error. When tree model is used, leaf value is refreshed after tree construction. If used in distributed training, the leaf value is calculated as the mean value from all workers, which is not guaranteed to be optimal.
   - ``binary:logistic``: logistic regression for binary classification, output probability
   - ``binary:logitraw``: logistic regression for binary classification, output score before logistic transformation
   - ``binary:hinge``: hinge loss for binary classification. This makes predictions of 0 or 1, rather than producing probabilities.

python-package/xgboost/core.py

@@ -105,6 +105,11 @@ def from_cstr_to_pystr(data: CStrPptr, length: c_bst_ulong) -> List[str]:
     return res
 
 
+def make_jcargs(**kwargs: Any) -> bytes:
+    "Make JSON-based arguments for C functions."
+    return from_pystr_to_cstr(json.dumps(kwargs))
+
+
 IterRange = TypeVar("IterRange", Optional[Tuple[int, int]], Tuple[int, int])
 
 
@@ -1256,7 +1261,7 @@ def __init__(self) -> None:  # pylint: disable=super-init-not-called
     def _set_data_from_cuda_interface(self, data: DataType) -> None:
         """Set data from CUDA array interface."""
         interface = data.__cuda_array_interface__
-        interface_str = bytes(json.dumps(interface, indent=2), "utf-8")
+        interface_str = bytes(json.dumps(interface), "utf-8")
         _check_call(
             _LIB.XGProxyDMatrixSetDataCudaArrayInterface(self.handle, interface_str)
         )
@@ -1357,6 +1362,26 @@ def __init__(  # pylint: disable=super-init-not-called
                 "Only one of the eval_qid or eval_group for each evaluation "
                 "dataset should be provided."
             )
+        if isinstance(data, DataIter):
+            if any(
+                info is not None
+                for info in (
+                    label,
+                    weight,
+                    base_margin,
+                    feature_names,
+                    feature_types,
+                    group,
+                    qid,
+                    label_lower_bound,
+                    label_upper_bound,
+                    feature_weights,
+                )
+            ):
+                raise ValueError(
+                    "If data iterator is used as input, data like label should be "
+                    "specified as batch argument."
+                )
 
         self._init(
             data,
@@ -1405,12 +1430,9 @@ def _init(
                 "in iterator to fix this error."
             )
 
-        args = {
-            "nthread": self.nthread,
-            "missing": self.missing,
-            "max_bin": self.max_bin,
-        }
-        config = from_pystr_to_cstr(json.dumps(args))
+        config = make_jcargs(
+            nthread=self.nthread, missing=self.missing, max_bin=self.max_bin
+        )
         ret = _LIB.XGQuantileDMatrixCreateFromCallback(
             None,
             it.proxy.handle,
@@ -2375,7 +2397,7 @@ def save_raw(self, raw_format: str = "deprecated") -> bytearray:
         """
         length = c_bst_ulong()
         cptr = ctypes.POINTER(ctypes.c_char)()
-        config = from_pystr_to_cstr(json.dumps({"format": raw_format}))
+        config = make_jcargs(format=raw_format)
         _check_call(
             _LIB.XGBoosterSaveModelToBuffer(
                 self.handle, config, ctypes.byref(length), ctypes.byref(cptr)
@@ -2570,9 +2592,6 @@ def get_score(
         `n_classes`, otherwise they're scalars.
         """
         fmap = os.fspath(os.path.expanduser(fmap))
-        args = from_pystr_to_cstr(
-            json.dumps({"importance_type": importance_type, "feature_map": fmap})
-        )
         features = ctypes.POINTER(ctypes.c_char_p)()
         scores = ctypes.POINTER(ctypes.c_float)()
         n_out_features = c_bst_ulong()
@@ -2582,7 +2601,7 @@ def get_score(
         _check_call(
             _LIB.XGBoosterFeatureScore(
                 self.handle,
-                args,
+                make_jcargs(importance_type=importance_type, feature_map=fmap),
                 ctypes.byref(n_out_features),
                 ctypes.byref(features),
                 ctypes.byref(out_dim),

python-package/xgboost/dask.py

@@ -573,6 +573,7 @@ def __init__(
         label_upper_bound: Optional[List[Any]] = None,
         feature_names: Optional[FeatureNames] = None,
         feature_types: Optional[Union[Any, List[Any]]] = None,
+        feature_weights: Optional[Any] = None,
     ) -> None:
         self._data = data
         self._label = label
@@ -583,6 +584,7 @@ def __init__(
         self._label_upper_bound = label_upper_bound
         self._feature_names = feature_names
         self._feature_types = feature_types
+        self._feature_weights = feature_weights
 
         assert isinstance(self._data, collections.abc.Sequence)
 
@@ -633,6 +635,7 @@ def next(self, input_data: Callable) -> int:
             label_upper_bound=self._get("_label_upper_bound"),
             feature_names=feature_names,
             feature_types=self._feature_types,
+            feature_weights=self._feature_weights,
         )
         self._iter += 1
         return 1
@@ -731,19 +734,21 @@ def _create_quantile_dmatrix(
         return d
 
     unzipped_dict = _get_worker_parts(parts)
-    it = DaskPartitionIter(**unzipped_dict)
+    it = DaskPartitionIter(
+        **unzipped_dict,
+        feature_types=feature_types,
+        feature_names=feature_names,
+        feature_weights=feature_weights,
+    )
 
     dmatrix = QuantileDMatrix(
         it,
         missing=missing,
-        feature_names=feature_names,
-        feature_types=feature_types,
         nthread=nthread,
         max_bin=max_bin,
         ref=ref,
         enable_categorical=enable_categorical,
     )
-    dmatrix.set_info(feature_weights=feature_weights)
     return dmatrix
 
 

python-package/xgboost/spark/core.py

@@ -747,6 +747,7 @@ def _fit(self, dataset):
             k: v for k, v in train_call_kwargs_params.items() if v is not None
         }
         dmatrix_kwargs = {k: v for k, v in dmatrix_kwargs.items() if v is not None}
+        use_qdm = booster_params.get("tree_method") in ("hist", "gpu_hist")
 
         def _train_booster(pandas_df_iter):
             """Takes in an RDD partition and outputs a booster for that partition after
@@ -759,20 +760,17 @@ def _train_booster(pandas_df_iter):
             context.barrier()
 
             gpu_id = None
+
+            if use_qdm and (booster_params.get("max_bin", None) is not None):
+                dmatrix_kwargs["max_bin"] = booster_params["max_bin"]
+
             if use_gpu:
                 gpu_id = context.partitionId() if is_local else _get_gpu_id(context)
                 booster_params["gpu_id"] = gpu_id
 
-                # max_bin is needed for qdm
-                if (
-                    features_cols_names is not None
-                    and booster_params.get("max_bin", None) is not None
-                ):
-                    dmatrix_kwargs["max_bin"] = booster_params["max_bin"]
-
             _rabit_args = {}
             if context.partitionId() == 0:
-                get_logger("XGBoostPySpark").info(
+                get_logger("XGBoostPySpark").debug(
                     "booster params: %s\n"
                     "train_call_kwargs_params: %s\n"
                     "dmatrix_kwargs: %s",
@@ -791,6 +789,7 @@ def _train_booster(pandas_df_iter):
                     pandas_df_iter,
                     features_cols_names,
                     gpu_id,
+                    use_qdm,
                     dmatrix_kwargs,
                     enable_sparse_data_optim=enable_sparse_data_optim,
                     has_validation_col=has_validation_col,