def abort(self):
        """Abort the processing_block."""
        LOG.debug('Aborting PB %s', self._id)
        self.set_status('aborted')
        pb_type = DB.get_hash_value(self.key, 'type')
        key = '{}:active'.format(self._type)
        DB.remove_from_list(key, self._id)
        key = '{}:active:{}'.format(self._type, pb_type)
        DB.remove_from_list(key, self._id)
        key = '{}:aborted'.format(self._type)
        DB.append_to_list(key, self._id)
        key = '{}:aborted:{}'.format(self._type, pb_type)
        DB.append_to_list(key, self._id)
        self._mark_updated()
Abort the processing_block.