Comment 23 for bug 1622616

Reviewed: https://review.openstack.org/373885
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=72f964a20ddac5f0d192eb7324c663fff877fb6e
Submitter: Jenkins
Branch: stable/newton

commit 72f964a20ddac5f0d192eb7324c663fff877fb6e
Author: Kevin Benton <email address hidden>
Date: Sun Sep 18 22:50:16 2016 -0700

    Don't immediately restart in DHCP agent on port change

    Now that the agent will receive port update events for
    all port changes[1], we need to avoid immediately restarting
    when the subnets on the agent's port changes. Otherwise
    the restart may request ports on a subnet which is in the
    process of being deleted. While the server is equipped to
    handle this, it makes subnet deletion much more contentious
    than it needs to be.

    This alters the logic to schedule a resync for later if the
    agent's port has had its subnets changed rather than restarting
    right away. Then by the time the agent eventually syncs the
    server should have finished deleting the subnet. Even if it hasn't,
    it spaces out the request from the agent for the network far enough
    that the operation will be much less frequent to avoid racing
    with the server.

    1. I607635601caff0322fd0c80c9023f5c4f663ca25

    Partial-Bug: #1622616
    Change-Id: I98761a7e3f4bce8d5485c885f03c6bfdde246802
    (cherry picked from commit 673abd56c906836d1e9aa14536139537100900c0)