Comment 5 for bug 1938478

Reviewed: https://review.opendev.org/c/openstack/neutron/+/848131
Committed: https://opendev.org/openstack/neutron/commit/cfc0678caf39a5ec002fc56a878275a94dc11b94
Submitter: "Zuul (22348)"
Branch: stable/yoga

commit cfc0678caf39a5ec002fc56a878275a94dc11b94
Author: zhouhenglc <email address hidden>
Date: Thu Jul 29 15:49:39 2021 +0800

    [ovn]support read chassis update time from nb_cfg_timestamp

    nb_cfg_timestamp: The timestamp when ovn-controller finishes
    processing the change corresponding to nb_cfg[1]. it can better
    reflect the status of chassis.

    This patch updated some unit tests. ensure mock 'time.time' is
    stopped after test. if not stop, may affect "timeutils.utcnow_ts"
    to obtain the real time, cause test case
    'test_agent_with_nb_cfg_timestamp_not_timeout' failure.

    Partial-bug: #1938478
    [1] https://www.ovn.org/support/dist-docs/ovn-sb.5.html

    Conflicts:
      neutron/plugins/ml2/drivers/ovn/agent/neutron_agent.py
      neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py

    Change-Id: Ia74a9404411862dc88b48c4a198d5c53f5f52704
    (cherry picked from commit 9e263dcf00b7ddc102a54f5e681bcf09931f3a72)