Comment 45 for bug 1597461

Reviewed: https://review.openstack.org/522792
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=385ac553e33f12c34e8a23459337b2f0af0b75eb
Submitter: Zuul
Branch: stable/ocata

commit 385ac553e33f12c34e8a23459337b2f0af0b75eb
Author: venkata anil <email address hidden>
Date: Thu Nov 23 18:40:30 2017 +0000

    Call update_all_ha_network_port_statuses on agent start

    As explained in bug [1] when l3 agent fails to report state to the
    server, its state is set to AGENT_REVIVED, triggering
    fetch_and_sync_all_routers, which will set all its HA network ports
    to DOWN, resulting in
    1) ovs agent rewiring these ports and setting status to ACTIVE
    2) when these ports are active, server sends router update to l3 agent
    As server, ovs and l3 agents are busy with this processing, l3 agent
    may fail again reporting state, repeating this process.

    As l3 agent is repeatedly processing same routers, SIGHUPs are
    frequently sent to keepalived, resulting in multiple masters.

    To fix this, we call update_all_ha_network_port_statuses in l3 agent
    start instead of calling from fetch_and_sync_all_routers.

    [1] https://bugs.launchpad.net/neutron/+bug/1731595/comments/7
    Conflicts:
     neutron/agent/l3/agent.py
            neutron/api/rpc/handlers/l3_rpc.py

    Note: This RPC update_all_ha_network_port_statuses is added in only pike
    and later branches. In older branches, we were using get_router_ids RPC
    to invoke _update_ha_network_port_status. As we need to invoke this
    functionality during l3 agent start and get_service_plugin_list() is the
    only available RPC which is called during l3 agent start, we call
    _update_ha_network_port_status from get_service_plugin_list.

    Change-Id: Ia9d5549f7d53b538c9c9f93fe6aa71ffff15524a
    Related-bug: #1597461
    Closes-Bug: #1731595
    (cherry picked from commit 9ab1ad1433d54fec3e5b04f1edf8ca436e1f7af1)
    (cherry picked from commit a6d985bbca57b5027eecaa43071964b14d9075d9)