Comment 14 for bug 1780373

Reviewed: https://review.openstack.org/581866
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=7858a84ee4d74e40adeecc0cf463e8937a1c5ada
Submitter: Zuul
Branch: stable/pike

commit 7858a84ee4d74e40adeecc0cf463e8937a1c5ada
Author: Matt Riedemann <email address hidden>
Date: Fri Jul 6 16:10:48 2018 -0400

    Add functional regressions tests for server_group_members OverQuota

    Since we started counting quotas in Pike, it is possible to bypass
    the server_group_members qouta check if either creating multiple
    servers in a single request or creating one server each in multiple
    concurrent requests. This is because the server_group_members
    count is based on existing server group members in the cell database
    and those group members (instances) don't get created in a cell until
    we get to conductor and after the scheduler picks a host. In other
    words, the server_group_members quota check in the API does not account
    for build requests.

    Change-Id: Icb268ca2f792bfcefd152ba4c6aa13270d9a7900
    Related-Bug: #1780373
    (cherry picked from commit f9874e059df50dc81803fcfdfd1045cc09624894)
    (cherry picked from commit c7b0779632a8df7d988e9b52ae1f341af0b0df30)