Support spark dataframe as input dataset and spark models as estimato…

…rs (microsoft#934)

* add basic support to Spark dataframe

add support to SynapseML LightGBM model

update to pyspark>=3.2.0 to leverage pandas_on_Spark API

* clean code, add TODOs

* add sample_train_data for pyspark.pandas dataframe, fix bugs

* improve some functions, fix bugs

* fix dict change size during iteration

* update model predict

* update LightGBM model, update test

* update SynapseML LightGBM params

* update synapseML and tests

* update TODOs

* Added support to roc_auc for spark models

* Added support to score of spark estimator

* Added test for automl score of spark estimator

* Added cv support to pyspark.pandas dataframe

* Update test, fix bugs

* Added tests

* Updated docs, tests, added a notebook

* Fix bugs in non-spark env

* Fix bugs and improve tests

* Fix uninstall pyspark

* Fix tests error

* Fix java.lang.OutOfMemoryError: Java heap space

* Fix test_performance

* Update test_sparkml to test_0sparkml to use the expected spark conf

* Remove unnecessary widgets in notebook

* Fix iloc java.lang.StackOverflowError

* fix pre-commit

* Added params check for spark dataframes

* Refactor code for train_test_split to a function

* Update train_test_split_pyspark

* Refactor if-else, remove unnecessary code

* Remove y from predict, remove mem control from n_iter compute

* Update workflow

* Improve _split_pyspark

* Fix test failure of too short training time

* Fix typos, improve docstrings

* Fix index errors of pandas_on_spark, add spark loss metric

* Fix typo of ndcgAtK

* Update NDCG metrics and tests

* Remove unuseful logger

* Use cache and count to ensure consistent indexes

* refactor for merge maain

* fix errors of refactor

* Updated SparkLightGBMEstimator and cache

* Updated config2params

* Remove unused import

* Fix unknown parameters

* Update default_estimator_list

* Add unit tests for spark metrics

.github/workflows/python-package.yml

@@ -25,7 +25,6 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-2019]
         python-version: ["3.7", "3.8", "3.9", "3.10"]
-
     steps:
       - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}
@@ -45,21 +44,18 @@ jobs:
           export CFLAGS="$CFLAGS -I/usr/local/opt/libomp/include"
           export CXXFLAGS="$CXXFLAGS -I/usr/local/opt/libomp/include"
           export LDFLAGS="$LDFLAGS -Wl,-rpath,/usr/local/opt/libomp/lib -L/usr/local/opt/libomp/lib -lomp"
-      - name: On Linux, install Spark stand-alone cluster and PySpark
-        if: matrix.os == 'ubuntu-latest'
+      - name: On Linux + python 3.8, install pyspark 3.2.3
+        if: matrix.os == 'ubuntu-latest' && matrix.python-version == '3.8'
         run: |
-          sudo apt-get update && sudo apt-get install -y --allow-downgrades --allow-change-held-packages --no-install-recommends ca-certificates-java ca-certificates openjdk-17-jdk-headless && sudo apt-get clean && sudo rm -rf /var/lib/apt/lists/*
-          wget --progress=dot:giga "https://www.apache.org/dyn/closer.lua/spark/spark-3.3.0/spark-3.3.0-bin-hadoop2.tgz?action=download" -O - | tar -xzC /tmp; archive=$(basename "spark-3.3.0/spark-3.3.0-bin-hadoop2.tgz") bash -c "sudo mv -v /tmp/\${archive/%.tgz/} /spark"
-          pip install --no-cache-dir pyspark>=3.0
-          export SPARK_HOME=/spark
-          export PYTHONPATH=/spark/python/lib/py4j-0.10.9.5-src.zip:/spark/python
-          export PATH=$PATH:$SPARK_HOME/bin
+          python -m pip install --upgrade pip wheel
+          pip install pyspark==3.2.3
       - name: Install packages and dependencies
         run: |
           python -m pip install --upgrade pip wheel
           pip install -e .
           python -c "import flaml"
           pip install -e .[test]
+          pip list | grep "pyspark"
       - name: If linux, install ray 2
         if: matrix.os == 'ubuntu-latest'
         run: |
@@ -76,6 +72,11 @@ jobs:
         if: matrix.python-version != '3.10'
         run: |
           pip install -e .[vw]
+      - name: Uninstall pyspark on python 3.9
+        if: matrix.python-version == '3.9'
+        run: |
+          # Uninstall pyspark to test env without pyspark
+          pip uninstall -y pyspark
       - name: Lint with flake8
         run: |
           # stop the build if there are Python syntax errors or undefined names

.gitignore

@@ -159,3 +159,6 @@ automl.pkl
 
 test/nlp/testtmp.py
 test/nlp/testtmpfl.py
+
+flaml/tune/spark/mylearner.py
+*.pkl

flaml/automl/automl.py

@@ -7,7 +7,6 @@
 import os
 import sys
 from typing import Callable, List, Union, Optional
-import inspect
 from functools import partial
 import numpy as np
 from sklearn.base import BaseEstimator
@@ -17,7 +16,6 @@
 
 from flaml.automl.state import SearchState, AutoMLState
 from flaml.automl.ml import (
-    compute_estimator,
     train_estimator,
     get_estimator_class,
 )
@@ -31,7 +29,6 @@
     N_SPLITS,
     SAMPLE_MULTIPLY_FACTOR,
 )
-from flaml.automl.data import concat
 
 # TODO check to see when we can remove these
 from flaml.automl.task.task import CLASSIFICATION, TS_FORECAST, Task
@@ -43,6 +40,34 @@
 from flaml.version import __version__ as flaml_version
 from flaml.tune.spark.utils import check_spark, get_broadcast_data
 
+try:
+    from flaml.automl.spark.utils import (
+        train_test_split_pyspark,
+        unique_pandas_on_spark,
+        len_labels,
+        unique_value_first_index,
+    )
+except ImportError:
+    train_test_split_pyspark = None
+    unique_pandas_on_spark = None
+    from flaml.automl.utils import (
+        len_labels,
+        unique_value_first_index,
+    )
+try:
+    os.environ["PYARROW_IGNORE_TIMEZONE"] = "1"
+    import pyspark.pandas as ps
+    from pyspark.pandas import DataFrame as psDataFrame, Series as psSeries
+    from pyspark.pandas.config import set_option, reset_option
+except ImportError:
+    ps = None
+
+    class psDataFrame:
+        pass
+
+    class psSeries:
+        pass
+
 
 try:
     import mlflow
@@ -511,7 +536,12 @@ def time_to_find_best_model(self) -> float:
         """Time taken to find best model in seconds."""
         return self.__dict__.get("_time_taken_best_iter")
 
-    def score(self, X: pd.DataFrame, y: pd.Series, **kwargs):
+    def score(
+        self,
+        X: Union[pd.DataFrame, psDataFrame],
+        y: Union[pd.Series, psSeries],
+        **kwargs,
+    ):
         estimator = getattr(self, "_trained_estimator", None)
         if estimator is None:
             logger.warning(
@@ -525,13 +555,14 @@ def score(self, X: pd.DataFrame, y: pd.Series, **kwargs):
 
     def predict(
         self,
-        X: Union[np.array, pd.DataFrame, List[str], List[List[str]]],
+        X: Union[np.array, pd.DataFrame, List[str], List[List[str]], psDataFrame],
         **pred_kwargs,
     ):
         """Predict label from features.
 
         Args:
-            X: A numpy array of featurized instances, shape n * m,
+            X: A numpy array or pandas dataframe or pyspark.pandas dataframe
+            of featurized instances, shape n * m,
                 or for time series forcast tasks:
                     a pandas dataframe with the first column containing
                     timestamp values (datetime type) or an integer n for
@@ -1859,7 +1890,19 @@ def is_to_reverse_metric(metric, task):
             error_metric = "customized metric"
         logger.info(f"Minimizing error metric: {error_metric}")
 
-        estimator_list = task.default_estimator_list(estimator_list)
+        is_spark_dataframe = isinstance(X_train, psDataFrame) or isinstance(
+            dataframe, psDataFrame
+        )
+        estimator_list = task.default_estimator_list(estimator_list, is_spark_dataframe)
+
+        if is_spark_dataframe and self._use_spark:
+            # For spark dataframe, use_spark must be False because spark models are trained in parallel themselves
+            self._use_spark = False
+            logger.warning(
+                "Spark dataframes support only spark.ml type models, which will be trained "
+                "with spark themselves, no need to start spark trials in flaml. "
+                "`use_spark` is set to False."
+            )
 
         # When no search budget is specified
         if no_budget:

flaml/automl/data.py

@@ -12,6 +12,22 @@
 from datetime import datetime
 from typing import TYPE_CHECKING, Union
 
+import os
+
+try:
+    os.environ["PYARROW_IGNORE_TIMEZONE"] = "1"
+    import pyspark.pandas as ps
+    from pyspark.pandas import DataFrame as psDataFrame, Series as psSeries
+except ImportError:
+    ps = None
+
+    class psDataFrame:
+        pass
+
+    class psSeries:
+        pass
+
+
 if TYPE_CHECKING:
     from flaml.automl.task import Task
 
@@ -198,6 +214,15 @@ def get_output_from_log(filename, time_budget):
 
 def concat(X1, X2):
     """concatenate two matrices vertically."""
+    if type(X1) != type(X2):
+        if isinstance(X2, (psDataFrame, psSeries)):
+            X1 = ps.from_pandas(pd.DataFrame(X1))
+        elif isinstance(X1, (psDataFrame, psSeries)):
+            X2 = ps.from_pandas(pd.DataFrame(X2))
+        else:
+            X1 = pd.DataFrame(X1)
+            X2 = pd.DataFrame(X2)
+
     if isinstance(X1, (DataFrame, Series)):
         df = pd.concat([X1, X2], sort=False)
         df.reset_index(drop=True, inplace=True)
@@ -206,6 +231,13 @@ def concat(X1, X2):
             if len(cat_columns):
                 df[cat_columns] = df[cat_columns].astype("category")
         return df
+    if isinstance(X1, (psDataFrame, psSeries)):
+        df = ps.concat([X1, X2], ignore_index=True)
+        if isinstance(X1, psDataFrame):
+            cat_columns = X1.select_dtypes(include="category").columns.values.tolist()
+            if len(cat_columns):
+                df[cat_columns] = df[cat_columns].astype("category")
+        return df
     if issparse(X1):
         return vstack((X1, X2))
     else:

flaml/automl/ml.py

@@ -2,6 +2,7 @@
 #  * Copyright (c) FLAML authors. All rights reserved.
 #  * Licensed under the MIT License. See LICENSE file in the
 #  * project root for license information.
+import os
 import time
 import numpy as np
 import pandas as pd
@@ -19,12 +20,6 @@
     mean_absolute_percentage_error,
     ndcg_score,
 )
-from sklearn.model_selection import (
-    RepeatedStratifiedKFold,
-    GroupKFold,
-    TimeSeriesSplit,
-    StratifiedGroupKFold,
-)
 from flaml.automl.model import (
     XGBoostSklearnEstimator,
     XGBoost_TS,
@@ -46,14 +41,33 @@
     TransformersEstimator,
     TemporalFusionTransformerEstimator,
     TransformersEstimatorModelSelection,
+    SparkLGBMEstimator,
 )
 from flaml.automl.data import group_counts
 from flaml.automl.task.task import TS_FORECAST, Task
 from flaml.automl.model import BaseEstimator
 
-import logging
+try:
+    from flaml.automl.spark.utils import len_labels
+except ImportError:
+    from flaml.automl.utils import len_labels
+try:
+    os.environ["PYARROW_IGNORE_TIMEZONE"] = "1"
+    from pyspark.sql.functions import col
+    import pyspark.pandas as ps
+    from pyspark.pandas import DataFrame as psDataFrame, Series as psSeries
+    from flaml.automl.spark.utils import to_pandas_on_spark, iloc_pandas_on_spark
+    from flaml.automl.spark.metrics import spark_metric_loss_score
+except ImportError:
+    ps = None
+
+    class psDataFrame:
+        pass
+
+    class psSeries:
+        pass
+
 
-logger = logging.getLogger(__name__)
 EstimatorSubclass = TypeVar("EstimatorSubclass", bound=BaseEstimator)
 
 sklearn_metric_name_set = {
@@ -124,6 +138,8 @@ def get_estimator_class(task: str, estimator_name: str) -> EstimatorSubclass:
         estimator_class = RF_TS if task in TS_FORECAST else RandomForestEstimator
     elif "lgbm" == estimator_name:
         estimator_class = LGBM_TS if task in TS_FORECAST else LGBMEstimator
+    elif "lgbm_spark" == estimator_name:
+        estimator_class = SparkLGBMEstimator
     elif "lrl1" == estimator_name:
         estimator_class = LRL1Classifier
     elif "lrl2" == estimator_name:
@@ -163,7 +179,15 @@ def metric_loss_score(
     groups=None,
 ):
     # y_processed_predict and y_processed_true are processed id labels if the original were the token labels
-    if is_in_sklearn_metric_name_set(metric_name):
+    if isinstance(y_processed_predict, (psDataFrame, psSeries)):
+        return spark_metric_loss_score(
+            metric_name,
+            y_processed_predict,
+            y_processed_true,
+            sample_weight,
+            groups,
+        )
+    elif is_in_sklearn_metric_name_set(metric_name):
         return sklearn_metric_loss_score(
             metric_name,
             y_processed_predict,
@@ -359,7 +383,10 @@ def sklearn_metric_loss_score(
 def get_y_pred(estimator, X, eval_metric, task: Task):
     if eval_metric in ["roc_auc", "ap", "roc_auc_weighted"] and task.is_binary():
         y_pred_classes = estimator.predict_proba(X)
-        y_pred = y_pred_classes[:, 1] if y_pred_classes.ndim > 1 else y_pred_classes
+        if isinstance(y_pred_classes, (psSeries, psDataFrame)):
+            y_pred = y_pred_classes
+        else:
+            y_pred = y_pred_classes[:, 1] if y_pred_classes.ndim > 1 else y_pred_classes
     elif eval_metric in [
         "log_loss",
         "roc_auc",
@@ -525,7 +552,7 @@ def compute_estimator(
     fit_kwargs: Optional[dict] = None,
     free_mem_ratio=0,
 ):
-    if not fit_kwargs:
+    if fit_kwargs is None:
         fit_kwargs = {}
 
     estimator_class = estimator_class or get_estimator_class(task, estimator_name)
@@ -605,7 +632,7 @@ def train_estimator(
         task=task,
         n_jobs=n_jobs,
     )
-    if not fit_kwargs:
+    if fit_kwargs is None:
         fit_kwargs = {}
 
     if isinstance(estimator, TransformersEstimator):