Dispose of database connection after init

backend/app.py

@@ -178,6 +178,13 @@ else:
         # cli.
         flask_migrate.Migrate(app, db)
 
+# Now that we've done all database interactions in the initialisation routines,
+# we need to drop all connections to the database to prevent those from being
+# shared among different worker processes.
+logging.info("Disposing of database connections.")
+with app.app_context():
+    db.engine.dispose()
+
 app.register_blueprint(api_v1)
 app.register_blueprint(web)
 app.register_blueprint(cli)