def __init__(
        self, use_pack_cache=True, use_runners_cache=False, fail_on_failure=False
    ):
        """
        :param use_pack_cache: True to cache which packs have been registered in memory and making
                                sure packs are only registered once.
        :type use_pack_cache: ``bool``

        :param use_runners_cache: True to cache RunnerTypeDB objects in memory to reduce load on
                                  the database.
        :type use_runners_cache: ``bool``

        :param fail_on_failure: Throw an exception if resource registration fails.
        :type fail_on_failure: ``bool``
        """
        self._use_pack_cache = use_pack_cache
        self._use_runners_cache = use_runners_cache
        self._fail_on_failure = fail_on_failure

        self._meta_loader = MetaLoader()
        self._override_loader = OverrideLoader()
        self._pack_loader = ContentPackLoader()

        # Maps runner name -> RunnerTypeDB
        self._runner_type_db_cache = {}

        :param use_pack_cache: True to cache which packs have been registered in memory and making
                                sure packs are only registered once.
        :type use_pack_cache: ``bool``

        :param use_runners_cache: True to cache RunnerTypeDB objects in memory to reduce load on
                                  the database.
        :type use_runners_cache: ``bool``

        :param fail_on_failure: Throw an exception if resource registration fails.
        :type fail_on_failure: ``bool``
        
st2common/st2common/bootstrap/base.py