See :py:func:`silverberg.client.CQLClient.execute`

def execute(self, *args, **kwargs):
        """
        See :py:func:`silverberg.client.CQLClient.execute`
        """
        num_clients = len(self._seed_clients)
        start_client = (self._client_idx + 1) % num_clients

        def _client_error(failure, client_i):
            failure.trap(ConnectError)
            client_i = (client_i + 1) % num_clients
            if client_i == start_client:
                return failure
            else:
                return _try_execute(client_i)

        def _try_execute(client_i):
            self._client_idx = client_i
            d = self._seed_clients[client_i].execute(*args, **kwargs)
            return d.addErrback(_client_error, client_i)

        return _try_execute(start_client)