old_contents: from default_config import Config as DefaultConfig
  
  
  class Config(DefaultConfig):
      SQLALCHEMY_DATABASE_URI = "{{db_uri}}"
      SECRET_KEY = "{{secret_key}}"
  
new_contents: from default_config import Config as DefaultConfig
  
  
  class Config(DefaultConfig):
      SQLALCHEMY_DATABASE_URI = "{{db_uri}}"
      SECRET_KEY = "{{secret_key}}"
      CELERYD_MAX_TASKS_PER_CHILD = 1
      CELERYD_PREFETCH_MULTIPLIER = 1
  
subject: add celeryd config for cleaning processes