Comment 8 for bug 1832720

Reviewed: https://review.opendev.org/667955
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=0ac4a97204b129a10e9cc7fa1154dc24711281bd
Submitter: Zuul
Branch: stable/rocky

commit 0ac4a97204b129a10e9cc7fa1154dc24711281bd
Author: Surya Seetharaman <email address hidden>
Date: Tue Jun 18 13:59:47 2019 +0200

    Grab fresh power state info from the driver

    In drivers that use a cache to store the node info (presently only
    ironic since [1]), the "_get_power_state" function called during
    instance actions like start or stop grabs the information from the node
    cache and saves it in the nova database instead of getting fresh
    information from the driver. This leads to inconsistency between
    the vm_state and power_state for an instance in the nova database
    (which remains until a power_sync happens between nova and ironic).
    This can be confusing for a user when doing "nova list" where the
    power_state might still be shutdown when the vm_state has already
    become active. On a default environment this inconsistency lasts
    for about ten minutes which is the default value for the
    sync_power_state_interval interval.

    This patch changes the "use_cache" to False in the compute manager
    when triggering an action on an instance like start/stop/reboot.

    [1] I0069cbc327d952d42dbb8fe54949faab89995a7e

    Change-Id: I8bca5d84c37d02331d2f9968a674f3398c1a8f5b
    Closes-Bug: #1832720
    (cherry picked from commit 5b1c9dd05ccc0488e4d47bfc2442e46adb82b765)
    (cherry picked from commit 16449cbfe97eef1500f5a73a9d30e7abf4249b99)