Address pandas timestamp warnings

mlos_bench/mlos_bench/environments/local/local_env.py

@@ -18,6 +18,7 @@
 from typing import Any, Dict, Iterable, List, Mapping, Optional, Tuple, Type, Union
 from typing_extensions import Literal
 
+import pytz
 import pandas
 
 from mlos_bench.environments.status import Status
@@ -215,6 +216,37 @@ def _normalize_columns(data: pandas.DataFrame) -> pandas.DataFrame:
             data.rename(str.rstrip, axis='columns', inplace=True)
         return data
 
+    # All timestamps in the telemetry data must be greater than this date
+    # (a very rough approximation for the start of this feature).
+    _MIN_TS = datetime(2024, 1, 1, 0, 0, 0, tzinfo=pytz.UTC)
+
+    @staticmethod
+    def _datetime_parser(datetime_col: pandas.Series) -> pandas.Series:
+        """
+        Attempt to convert a column to a datetime format.
+
+        Parameters
+        ----------
+        datetime_col : pandas.Series
+            The column to convert.
+
+        Returns
+        -------
+        pandas.Series
+            The converted datetime column.
+
+        Raises
+        ------
+        ValueError
+            On parse errors.
+        """
+        new_datetime_col = pandas.to_datetime(datetime_col, utc=True)
+        if new_datetime_col.isna().any():
+            raise ValueError(f"Invalid date format in the telemetry data: {datetime_col}")
+        if new_datetime_col.le(LocalEnv._MIN_TS).any():
+            raise ValueError(f"Invalid date range in the telemetry data: {datetime_col}")
+        return new_datetime_col
+
     def status(self) -> Tuple[Status, datetime, List[Tuple[datetime, str, Any]]]:
 
         (status, timestamp, _) = super().status()
@@ -229,8 +261,10 @@ def status(self) -> Tuple[Status, datetime, List[Tuple[datetime, str, Any]]]:
             # TODO: Use the timestamp of the CSV file as our status timestamp?
 
             # FIXME: We should not be assuming that the only output file type is a CSV.
+
             data = self._normalize_columns(
-                pandas.read_csv(fname, index_col=False, parse_dates=[0]))
+                pandas.read_csv(fname, index_col=False))
+            data.iloc[:, 0] = self._datetime_parser(data.iloc[:, 0])
 
             expected_col_names = ["timestamp", "metric", "value"]
             if len(data.columns) != len(expected_col_names):
@@ -239,7 +273,8 @@ def status(self) -> Tuple[Status, datetime, List[Tuple[datetime, str, Any]]]:
             if list(data.columns) != expected_col_names:
                 # Assume no header - this is ok for telemetry data.
                 data = pandas.read_csv(
-                    fname, index_col=False, parse_dates=[0], names=expected_col_names)
+                    fname, index_col=False, names=expected_col_names)
+                data.iloc[:, 0] = self._datetime_parser(data.iloc[:, 0])
 
         except FileNotFoundError as ex:
             _LOG.warning("Telemetry CSV file not found: %s :: %s", self._read_telemetry_file, ex)

mlos_bench/mlos_bench/tests/environments/local/composite_local_env_test.py

@@ -7,6 +7,7 @@
 """
 import sys
 from datetime import datetime, timedelta
+import pytz
 
 from mlos_bench.tunables.tunable_groups import TunableGroups
 from mlos_bench.tests.environments import check_env_success
@@ -22,12 +23,12 @@ def test_composite_env(tunable_groups: TunableGroups) -> None:
     can be used in the shell_envs by its children.
     See Also: http://github.com/microsoft/MLOS/issues/501
     """
-    ts1 = datetime.utcnow()
+    ts1 = datetime.utcnow().astimezone(pytz.UTC)
     ts1 -= timedelta(microseconds=ts1.microsecond)  # Round to a second
     ts2 = ts1 + timedelta(minutes=2)
 
-    time_str1 = ts1.strftime("%Y-%m-%d %H:%M:%S")
-    time_str2 = ts2.strftime("%Y-%m-%d %H:%M:%S")
+    time_str1 = ts1.strftime("%Y-%m-%d %H:%M:%S %z")
+    time_str2 = ts2.strftime("%Y-%m-%d %H:%M:%S %z")
 
     (var_prefix, var_suffix) = ("%", "%") if sys.platform == 'win32' else ("$", "")
 

mlos_bench/mlos_bench/tests/environments/local/local_env_telemetry_test.py

@@ -6,6 +6,9 @@
 Unit tests for telemetry and status of LocalEnv benchmark environment.
 """
 from datetime import datetime, timedelta
+import pytz
+
+import pytest
 
 from mlos_bench.tunables.tunable_groups import TunableGroups
 from mlos_bench.tests.environments import check_env_success, check_env_fail_telemetry
@@ -16,12 +19,12 @@ def test_local_env_telemetry(tunable_groups: TunableGroups) -> None:
     """
     Produce benchmark and telemetry data in a local script and read it.
     """
-    ts1 = datetime.utcnow()
+    ts1 = datetime.utcnow().astimezone(pytz.UTC)
     ts1 -= timedelta(microseconds=ts1.microsecond)  # Round to a second
     ts2 = ts1 + timedelta(minutes=1)
 
-    time_str1 = ts1.strftime("%Y-%m-%d %H:%M:%S")
-    time_str2 = ts2.strftime("%Y-%m-%d %H:%M:%S")
+    time_str1 = ts1.strftime("%Y-%m-%d %H:%M:%S %z")
+    time_str2 = ts2.strftime("%Y-%m-%d %H:%M:%S %z")
 
     local_env = create_local_env(tunable_groups, {
         "run": [
@@ -60,12 +63,12 @@ def test_local_env_telemetry_no_header(tunable_groups: TunableGroups) -> None:
     """
     Read the telemetry data with no header.
     """
-    ts1 = datetime.utcnow()
+    ts1 = datetime.utcnow().astimezone(pytz.UTC)
     ts1 -= timedelta(microseconds=ts1.microsecond)  # Round to a second
     ts2 = ts1 + timedelta(minutes=1)
 
-    time_str1 = ts1.strftime("%Y-%m-%d %H:%M:%S")
-    time_str2 = ts2.strftime("%Y-%m-%d %H:%M:%S")
+    time_str1 = ts1.strftime("%Y-%m-%d %H:%M:%S %z")
+    time_str2 = ts2.strftime("%Y-%m-%d %H:%M:%S %z")
 
     local_env = create_local_env(tunable_groups, {
         "run": [
@@ -89,16 +92,17 @@ def test_local_env_telemetry_no_header(tunable_groups: TunableGroups) -> None:
     )
 
 
+@pytest.mark.filterwarnings("ignore:.*(Could not infer format, so each element will be parsed individually, falling back to `dateutil`).*:UserWarning::0")  # pylint: disable=line-too-long # noqa
 def test_local_env_telemetry_wrong_header(tunable_groups: TunableGroups) -> None:
     """
     Read the telemetry data with incorrect header.
     """
-    ts1 = datetime.utcnow()
+    ts1 = datetime.utcnow().astimezone(pytz.UTC)
     ts1 -= timedelta(microseconds=ts1.microsecond)  # Round to a second
     ts2 = ts1 + timedelta(minutes=1)
 
-    time_str1 = ts1.strftime("%Y-%m-%d %H:%M:%S")
-    time_str2 = ts2.strftime("%Y-%m-%d %H:%M:%S")
+    time_str1 = ts1.strftime("%Y-%m-%d %H:%M:%S %z")
+    time_str2 = ts2.strftime("%Y-%m-%d %H:%M:%S %z")
 
     local_env = create_local_env(tunable_groups, {
         "run": [
@@ -119,12 +123,12 @@ def test_local_env_telemetry_invalid(tunable_groups: TunableGroups) -> None:
     """
     Fail when the telemetry data has wrong format.
     """
-    ts1 = datetime.utcnow()
+    ts1 = datetime.utcnow().astimezone(pytz.UTC)
     ts1 -= timedelta(microseconds=ts1.microsecond)  # Round to a second
     ts2 = ts1 + timedelta(minutes=1)
 
-    time_str1 = ts1.strftime("%Y-%m-%d %H:%M:%S")
-    time_str2 = ts2.strftime("%Y-%m-%d %H:%M:%S")
+    time_str1 = ts1.strftime("%Y-%m-%d %H:%M:%S %z")
+    time_str2 = ts2.strftime("%Y-%m-%d %H:%M:%S %z")
 
     local_env = create_local_env(tunable_groups, {
         "run": [