def initiate(self, **kwargs):
        '''Establishes the connections to database and messaging platform,
        taking into account that it might meen performing asynchronous job.'''
        run_startup = kwargs.pop('run_startup', True)

        setter = lambda value, name: setattr(self, name, value)

        d = defer.Deferred()
        d.addCallback(defer.drop_param,
                      self.agency._messaging.get_connection, self)
        d.addCallback(setter, "_messaging")
        d.addCallback(defer.drop_param,
                      self.agency._database.get_connection)
        d.addCallback(setter, '_database')
        d.addCallback(defer.drop_param,
                      self._reload_descriptor)
        d.addCallback(defer.drop_param,
                      self._subscribe_for_descriptor_changes)
        d.addCallback(defer.drop_param, self._store_instance_id)
        d.addCallback(defer.drop_param, self._load_configuration)
        d.addCallback(setter, '_configuration')
        d.addCallback(defer.drop_param,
                      self.join_shard, self._descriptor.shard)
        d.addCallback(defer.drop_param,
                      self.journal_agent_created)
        d.addCallback(defer.drop_param,
                      self._call_initiate, **kwargs)
        d.addCallback(defer.drop_param, self.call_next, self._call_startup,
                      call_startup=run_startup)
        d.addCallback(defer.override_result, self)
        d.addErrback(self._startup_error)

        # Ensure the execution chain is broken
        self.call_next(d.callback, None)

        return d
Establishes the connections to database and messaging platform,
        taking into account that it might meen performing asynchronous job.