'Ask master server for mapping.'

def RenewMapping(self):

    try:
        res = self.pool.urlopen('POST', '/server/mapping')
        if (res.status != constants.RESPONSE_OK):
            raise errors.DataServerError('Could    not    get    server    mapping    from    data    master.')
        mapping = rdf_data_server.DataServerMapping.FromSerializedString(res.data)
        self.handler_cls.SERVICE.SaveServerMapping(mapping)
        return mapping
    except urllib3.exceptions.MaxRetryError:
        raise errors.DataServerError('Error    when    attempting    to    communicate    with    data    master.')
