Make GCP region configurable for managed ML diagnostics runs in MaxText

to support multi-region deployments.
`managed_mldiagnostics_region` defaults to empty string. When empty,
the SDK will auto-detect the region from GCP metadata server.

- Add strictly typed `managed_mldiagnostics_region`: str = "" to `ManagedMLDiagnostics` Pydantic class in `types.py`.
- Add `managed_mldiagnostics_region`: "" to `base.yml`.
- Pass configured region directly to `machinelearning_run` in `managed_mldiagnostics.py`, falling back to `None` if empty to trigger SDK auto-detection.

PiperOrigin-RevId: 932279476

Author: Google-ML-Automation

src/maxtext/common/managed_mldiagnostics.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 """Create the managed mldiagnostics run."""
+
 import json
 from typing import Any
 
@@ -24,16 +25,16 @@
 
 
 class ManagedMLDiagnostics:
-  """
-  ML Diagnostics Run, implemented with the Singleton pattern.
+  """ML Diagnostics Run, implemented with the Singleton pattern.
+
   Ensures that only one instance of the class can exist.
   """
 
   _instance = None  # Class attribute to hold the single instance
 
   def __new__(cls, *args: Any, **kwargs: Any):
-    """
-    Overrides the instance creation method.
+    """Overrides the instance creation method.
+
     If an instance already exists, it is returned instead of creating a new one.
     """
     if cls._instance is None:
@@ -42,9 +43,7 @@ def __new__(cls, *args: Any, **kwargs: Any):
     return cls._instance
 
   def __init__(self, config):
-    """
-    Initializes the ManagedMLDiagnostics, ensuring this method runs only once.
-    """
+    """Initializes the ManagedMLDiagnostics, ensuring this method runs only once."""
     # We need a flag to ensure __init__ only runs once,
     # as the object is returned multiple times by __new__.
     if hasattr(self, "_initialized"):
@@ -67,11 +66,11 @@ def should_log_key(key, value):
     config_dict = {key: value for key, value in config.get_keys().items() if should_log_key(key, value)}
 
     # Create a run for the managed mldiagnostics, and upload the configuration.
+    region = config.managed_mldiagnostics_region if config.managed_mldiagnostics_region else None
     mldiag.machinelearning_run(
         name=f"{config.run_name}",
         run_group=config.managed_mldiagnostics_run_group,
         configs=config_dict,
         gcs_path=config.managed_mldiagnostics_dir,
-        # TODO: b/455623960 - Remove the following once multi-region and prod support are enabled.
-        region="us-central1",
+        region=region,
     )

src/maxtext/configs/base.yml

@@ -839,6 +839,7 @@ tpu_num_sparse_cores_to_trace: 2
 # - upload training metrics, at the defined log_period interval.
 managed_mldiagnostics: false # Whether to enable the managed diagnostics
 managed_mldiagnostics_run_group: ""  # Optional. Used to group multiple runs.
+managed_mldiagnostics_region: "" # Optional. GCP region for managed mldiagnostics. If empty, it will be auto-detected by the SDK.
 
 # Dump HLO and jaxpr options
 dump_hlo: false

src/maxtext/configs/types.py

@@ -1786,6 +1786,7 @@ class ManagedMLDiagnostics(BaseModel):
 
   managed_mldiagnostics: bool = Field(False, description="Enable managed mldiagnostics.")
   managed_mldiagnostics_run_group: str = Field("", description="Name used to group multiple runs.")
+  managed_mldiagnostics_region: str = Field("", description="GCP region for managed mldiagnostics.")
 
 
 class Goodput(BaseModel):

tests/unit/managed_mldiagnostics_test.py

@@ -0,0 +1,81 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Unit tests for ManagedMLDiagnostics."""
+
+import unittest
+from unittest import mock
+
+from maxtext.common.managed_mldiagnostics import ManagedMLDiagnostics
+import pytest
+
+
+@pytest.mark.cpu_only
+class ManagedMLDiagnosticsTest(unittest.TestCase):
+  # pylint: disable=protected-access
+
+  def setUp(self):
+    super().setUp()
+    # Reset singleton instance between tests
+    ManagedMLDiagnostics._instance = None
+
+  def test_not_enabled_noop(self):
+    mock_config = mock.MagicMock()
+    mock_config.managed_mldiagnostics = False
+
+    with mock.patch.object(ManagedMLDiagnostics.mldiag, "machinelearning_run") as mock_run:
+      ManagedMLDiagnostics(mock_config)
+      mock_run.assert_not_called()
+
+  def test_enabled_empty_region_passes_none(self):
+    mock_config = mock.MagicMock()
+    mock_config.managed_mldiagnostics = True
+    mock_config.managed_mldiagnostics_region = ""
+    mock_config.run_name = "test_run"
+    mock_config.managed_mldiagnostics_run_group = "test_group"
+    mock_config.managed_mldiagnostics_dir = "gs://test_dir"
+    mock_config.get_keys.return_value = {"key1": "val1"}
+
+    with mock.patch.object(ManagedMLDiagnostics.mldiag, "machinelearning_run") as mock_run:
+      ManagedMLDiagnostics(mock_config)
+      mock_run.assert_called_once_with(
+          name="test_run",
+          run_group="test_group",
+          configs={"key1": "val1"},
+          gcs_path="gs://test_dir",
+          region=None,
+      )
+
+  def test_enabled_populated_region_passes_region(self):
+    mock_config = mock.MagicMock()
+    mock_config.managed_mldiagnostics = True
+    mock_config.managed_mldiagnostics_region = "us-east1"
+    mock_config.run_name = "test_run"
+    mock_config.managed_mldiagnostics_run_group = "test_group"
+    mock_config.managed_mldiagnostics_dir = "gs://test_dir"
+    mock_config.get_keys.return_value = {"key1": "val1"}
+
+    with mock.patch.object(ManagedMLDiagnostics.mldiag, "machinelearning_run") as mock_run:
+      ManagedMLDiagnostics(mock_config)
+      mock_run.assert_called_once_with(
+          name="test_run",
+          run_group="test_group",
+          configs={"key1": "val1"},
+          gcs_path="gs://test_dir",
+          region="us-east1",
+      )
+
+
+if __name__ == "__main__":
+  unittest.main()