Comment 15 for bug 1511311

Reviewed: https://review.openstack.org/259061
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=3a70a5b236514711d7ff924f657e41fa7d70d30a
Submitter: Jenkins
Branch: stable/liberty

commit 3a70a5b236514711d7ff924f657e41fa7d70d30a
Author: Hong Hui Xiao <email address hidden>
Date: Wed Nov 4 01:44:43 2015 -0500

    Kill the vrrp orphan process when (re)spawn keepalived

    When keepalived crashed unexpectedly, the vrrp process that
    it associates with will be orphan process. This will make
    the VIP unable to migrate to the router in the same host.
    Also, neutron code is not able to respawn the keepalived
    process, because keepalived thinks itself is still running,
    according to [1-3]. As a result, neutron will report respawning
    keepalived all the time. Restart l3-agent will not help.

    This patch will check and delete the orphan vrrp process
    if there is any, in the processmonitor of l3 agent.

    More details can be found in the bug description and comments.

    [1] https://goo.gl/W3GL9I
    [2] https://goo.gl/F0Ixfb
    [3] https://goo.gl/dUqhTo

    Change-Id: Ia1759ed1365b845d404686a8cd25f882cce35caf
    Closes-Bug: #1511311
    (cherry picked from commit 2d1b53bcfa6c4d6fa5bca2ba4da9aaca66245a5b)