Comment 2 for bug 1899541

Reviewed: https://review.opendev.org/757656
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=1c256cf774693e2395ae8fe4a7a2f416a7aeb03a
Submitter: Zuul
Branch: master

commit 1c256cf774693e2395ae8fe4a7a2f416a7aeb03a
Author: melanie witt <email address hidden>
Date: Mon Oct 12 22:27:52 2020 +0000

    Prevent archiving of pci_devices records because of 'instance_uuid'

    Currently in the archive_deleted_rows code, we will attempt to clean up
    "residue" of deleted instance records by assuming any table with a
    'instance_uuid' column represents data tied to an instance's lifecycle
    and delete such records.

    This behavior poses a problem in the case where an instance has a PCI
    device allocated and someone deletes the instance. The 'instance_uuid'
    column in the pci_devices table is used to track the allocation
    association of a PCI with an instance. There is a small time window
    during which the instance record has been deleted but the PCI device
    has not yet been freed from a database record perspective as PCI
    devices are freed during the _complete_deletion method in the compute
    manager as part of the resource tracker update call.

    Records in the pci_devices table are anyway not related to the
    lifecycle of instances so they should not be considered residue to
    clean up if an instance is deleted. This adds a condition to avoid
    archiving pci_devices on the basis of an instance association.

    Closes-Bug: #1899541

    Change-Id: Ie62d3566230aa3e2786d129adbb2e3570b06e4c6