Maintenance Mode Fix (#6422)

* Custom maintenance mode backend

* Implement check and retries

* Update debug formatting

InvenTree/InvenTree/backends.py

@@ -0,0 +1,59 @@
+"""Custom backend implementations."""
+
+import logging
+import time
+
+from django.db.utils import IntegrityError, OperationalError, ProgrammingError
+
+from maintenance_mode.backends import AbstractStateBackend
+
+import common.models
+import InvenTree.helpers
+
+logger = logging.getLogger('inventree')
+
+
+class InvenTreeMaintenanceModeBackend(AbstractStateBackend):
+    """Custom backend for managing state of maintenance mode.
+
+    Stores the current state of the maintenance mode in the database,
+    using an InvenTreeSetting object.
+    """
+
+    SETTING_KEY = '_MAINTENANCE_MODE'
+
+    def get_value(self) -> bool:
+        """Get the current state of the maintenance mode.
+
+        Returns:
+            bool: True if maintenance mode is active, False otherwise.
+        """
+        value = InvenTree.helpers.str2bool(
+            common.models.InvenTreeSetting.get_setting(
+                self.SETTING_KEY, backup_value=False, create=False, cache=False
+            )
+        )
+
+        logger.debug('Maintenance mode state: %s', value)
+
+        return value
+
+    def set_value(self, value: bool, retries: int = 5):
+        """Set the state of the maintenance mode."""
+        logger.debug('Setting maintenance mode state: %s', value)
+
+        while retries > 0:
+            try:
+                common.models.InvenTreeSetting.set_setting(self.SETTING_KEY, value)
+
+                # Read the value back to confirm
+                if self.get_value() == value:
+                    break
+            except (IntegrityError, OperationalError, ProgrammingError):
+                logger.warning(
+                    'Failed to set maintenance mode state in database (%s retries left)',
+                    retries,
+                )
+                time.sleep(0.1)
+
+            retries -= 1

InvenTree/InvenTree/settings.py

@@ -1080,8 +1080,8 @@ MARKDOWNIFY = {
 IGNORED_ERRORS = [Http404, django.core.exceptions.PermissionDenied]
 
 # Maintenance mode
-MAINTENANCE_MODE_RETRY_AFTER = 60
-MAINTENANCE_MODE_STATE_BACKEND = 'maintenance_mode.backends.StaticStorageBackend'
+MAINTENANCE_MODE_RETRY_AFTER = 10
+MAINTENANCE_MODE_STATE_BACKEND = 'InvenTree.backends.InvenTreeMaintenanceModeBackend'
 
 # Are plugins enabled?
 PLUGINS_ENABLED = get_boolean_setting(