Comment 8 for bug 1930926

Reviewed: https://review.opendev.org/c/openstack/neutron/+/795614
Committed: https://opendev.org/openstack/neutron/commit/073d6d7eeaf1b4ae0bd0c326956888eaaed168f7
Submitter: "Zuul (22348)"
Branch: stable/ussuri

commit 073d6d7eeaf1b4ae0bd0c326956888eaaed168f7
Author: Terry Wilson <email address hidden>
Date: Fri Jun 4 19:47:36 2021 +0000

    Use TCP keepalives for ovsdb connections

    When failing over OVN DB servers from one server to another, the
    server which originally hosted the VIP doesn't notice the connection
    is gone and doesn't reconnect. Ultimately, this is something that
    needs to be fixed in python-ovs, but setting the SO_KEEPALIVE socket
    option avoids the issue. This also has the benefit that the client
    doesn't need to send 'echo' requests, which can time out on an
    overloaded ovsdb-server, which causes a disconnection which then
    adds even more load on the ovsdb-server as it has to send the entire
    db contents over the wire after the connection.

    Conflicts: neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/impl_idl_ovn.py

    Closes-Bug: #1930926
    Change-Id: Ie0205785cab307c132fbe409588739685cade7c0
    (cherry picked from commit 65cce351d74a9a637fdb2a9d5e0e63445dda9ea9)