Comment 3 for bug 1052157

Reviewed: https://review.openstack.org/13182
Committed: http://github.com/openstack/nova/commit/8e851409f3a8a345ec954a880c81232fbf9e27b4
Submitter: Jenkins
Branch: master

commit 8e851409f3a8a345ec954a880c81232fbf9e27b4
Author: Brian Elliott <email address hidden>
Date: Fri Sep 14 15:17:07 2012 +0000

    Fix bugs in resource tracker and cleanup

    Fixes bugs in resource tracker:
    * Handle disk oversubscription
    * Handle suspended/powered off instances

    The usage model is changed to the old style that is
    based on actual instance usage on a compute host.
    (Not the current point in time of the hypervisor's
     reported host stats)

    There is now a 'limits' filter property that can be passed from
    the scheduler to the compute node to indicate that
    oversubscription of resources is desired:

    The 'limits' filter property is a dict with the following possible
    keys:

    * memory_mb - Specifies the memory ceiling for the compute node.
    * disk_gb - Specifies the disk space ceiling for the compute node.
    * vcpu - Specifies the max number of vcpus for the compute node.

    There is also some general cleanup and additional unit tests in
    an attempt to simplify down this function.

    bug 1048842
    bug 1052157

    Change-Id: I6ee851b8c03234a78a64d9f5c494dfc7059cdda4