def get_collectd_rpm_suffix(distro_number, target_cpu,
                            collectd_version_release):
    """
    Return the suffix of Collectd RPMs.
    The suffix starts from "-", e.g.
    "-5.11.0.gadf6f83.lustre-1.el7.x86_64.rpm"
    """
    return ("-%s.el%s.%s.rpm" %
            (collectd_version_release, distro_number, target_cpu))