Comment 2 for bug 2043036

Reviewed: https://review.opendev.org/c/openstack/nova/+/900831
Committed: https://opendev.org/openstack/nova/commit/fa3cf7d50cba921ea67eb161e6a199067ea62deb
Submitter: "Zuul (22348)"
Branch: master

commit fa3cf7d50cba921ea67eb161e6a199067ea62deb
Author: Jay Faulkner <email address hidden>
Date: Mon Nov 13 15:21:31 2023 -0800

    [ironic] Partition & use cache for list_instance*

    list_instances and list_instance_uuids, as written in the Ironic driver,
    do not currently respect conductor_group paritioning. Given a nova
    compute is intended to limit it's scope of work to the conductor group
    it is configured to work with; this is a bug.

    Additionally, this should be a significant performance boost for a
    couple of reasons; firstly, instead of calling the Ironic API and
    getting all nodes, instead of the subset (when using conductor group),
    we're now properly getting the subset of nodes -- this is the optimized
    path in the Ironic DB and API code. Secondly, we're now using the
    driver's node cache to respond to these requests. Since list_instances
    and list_instance_uuids is used by periodic tasks, these operating with
    data that may be slightly stale should have minimal impact compared to
    the performance benefits.

    Closes-bug: #2043036
    Change-Id: If31158e3269e5e06848c29294fdaa147beedb5a5