attempts to eliminate database connection errors

app/__init__.py

@@ -5,6 +5,7 @@ from flask_sqlalchemy import SQLAlchemy
 from flask_migrate import Migrate
 from flask_login import LoginManager
 
+
 db = SQLAlchemy()
 migrate = Migrate()
 login_manager = LoginManager()
@@ -12,8 +13,9 @@ login_manager = LoginManager()
 def create_app(config_class='config.Config'):
     app = Flask(__name__)
     app.config.from_object(config_class)
-
+    app.config['SQLALCHEMY_ENGINE_OPTIONS'] = {
-    app.config['SQLALCHEMY_ENGINE_OPTIONS'] = config_class.SQLALCHEMY_ENGINE_OPTIONS
+        "pool_pre_ping": True
+    }
 
     db.init_app(app)
     migrate.init_app(app, db)

config.py

@@ -28,6 +28,3 @@ class Config:
 
     SQLALCHEMY_TRACK_MODIFICATIONS = False
 
-    SQLALCHEMY_ENGINE_OPTIONS = {
-        "pool_pre_ping": True
-    }

image_import_worker.py

@@ -1,6 +1,7 @@
 # image_import_worker.py
 import time
 import os
+from sqlalchemy.exc import OperationalError
 from app import create_app
 from app.utils.image_importer import import_images_task
 
@@ -19,11 +20,26 @@ def monitor_and_import():
         while True:
             if os.path.exists(TRIGGER_FLAG):
                 print("[Image Importer] Trigger flag found. Starting import...")
+                max_retries = 3
+                attempt = 0
+
+                while attempt < max_retries:
                     try:
                         result = import_images_task(SOURCE_DIR, DEST_DIR)
                         print(f"[Image Importer] {result}")
+                        break  # Exit retry loop if successful
+                    except OperationalError as e:
+                        attempt += 1
+                        print(f"[Image Importer] Database error during import (attempt {attempt}): {e}")
+                        if attempt >= max_retries:
+                            print("[Image Importer] Max retries reached. Import failed.")
+                        else:
+                            sleep_time = 2 ** attempt
+                            print(f"[Image Importer] Retrying in {sleep_time} seconds...")
+                            time.sleep(sleep_time)
                     except Exception as e:
-                    print(f"[Image Importer] Error during import: {e}")
+                        print(f"[Image Importer] Unexpected error during import: {e}")
+                        break
                     finally:
                         try:
                             os.remove(TRIGGER_FLAG)
@@ -31,9 +47,12 @@ def monitor_and_import():
                         except Exception as e:
                             print(f"[Image Importer] Failed to remove trigger flag: {e}")
 
-            # Thumbnail generation Check
             if os.path.exists(THUMBNAIL_FLAG):
                 print("[Image Importer] Thumbnail regeneration triggered.")
+                max_retries = 3
+                attempt = 0
+
+                while attempt < max_retries:
                     try:
                         from app.models import ImageRecord
                         from app.utils.image_importer import generate_thumbnail
@@ -44,9 +63,19 @@ def monitor_and_import():
                                 print(f"[Thumbnail] Regenerated for {img.filename}")
                             except Exception as e:
                                 print(f"[Thumbnail] Failed for {img.filename}: {e}")
-                        time.sleep(1)
+                        break  # Success
+                    except OperationalError as e:
+                        attempt += 1
+                        print(f"[Image Importer] Database error during thumbnail regen (attempt {attempt}): {e}")
+                        if attempt >= max_retries:
+                            print("[Image Importer] Max retries reached. Thumbnail regeneration failed.")
+                        else:
+                            sleep_time = 2 ** attempt
+                            print(f"[Image Importer] Retrying in {sleep_time} seconds...")
+                            time.sleep(sleep_time)
                     except Exception as e:
-                    print(f"[Image Importer] Error during thumbnail regeneration: {e}")
+                        print(f"[Image Importer] Unexpected error during thumbnail regen: {e}")
+                        break
                     finally:
                         try:
                             os.remove(THUMBNAIL_FLAG)