Comment 9 for bug 1830774

Reviewed: https://review.opendev.org/663813
Committed: https://git.openstack.org/cgit/starlingx/metal/commit/?id=3c86ec443f9098b4a41c03ef6295d6af376d35a5
Submitter: Zuul
Branch: master

commit 3c86ec443f9098b4a41c03ef6295d6af376d35a5
Author: Eric MacDonald <email address hidden>
Date: Thu Jun 6 21:12:54 2019 -0400

    Make heartbeat cluster state change notifications immediate

    Investigation of the reported issue lead to the discovery
    that the heartbeat service was not sending a cluster state
    change notification after detecting that the peer controller
    was no longer providing its cluster state view.

    This update makes the following two cluster state change
    notification improvements to ensure that SM is notified
    immeditely following all cluster state changes.

    1. send SM current cluster state view notification as soon
       as the state change is detected rather than waiting for
       the end of the heartbeat period.

    2. consider the loss of the peer controller cluster view as
       a cluster state change that, like other state changes,
       warrants an immeduiate notification.

    Test Plan:

    PASS: Inspect heartbeat service logs for expected behavior.
    PASS: Reboot the active controller 10+ times and verify SM
          switches activity to the inservice peer controller in
          a timely manner.

    Change-Id: Iebf466a6d75e2f56fae1fdbdfc148127db139c99
    Closes-Bug: 1830774
    Signed-off-by: Eric MacDonald <email address hidden>