with cells, instances can go from active back to build

[Chris Behrens]

The build process for instances can send a lot of state changes very quickly. For the most part, it doesn't matter too much if they come in out of order. However, the final message setting the instance to the ACTIVE state is important. After we've seen an instance go ACTIVE, we should never reset it back to BUILDING.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/29215

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/29215
Committed: http://github.com/openstack/nova/commit/9dd6db4baec104fe811be8fecece40c05788cdff
Submitter: Jenkins
Branch: master

commit 9dd6db4baec104fe811be8fecece40c05788cdff
Author: Chris Behrens <email address hidden>
Date: Wed May 15 09:09:10 2013 +0000

    Cells: Don't allow active -> build

    Adds support for passing 'expected_vm_state' in an instance_update dict
    much like the current support for 'expected_task_state'.

    For cells, when the API cell receives an instance update containing a
    vm_state of BUILDING, raise an exception if the instance is in some
    other state. This addresses out-of-order messaging issues that can
    cause an instance to appear to have a huge delay going ACTIVE. (A
    periodic task run can later heal the state, but it can take a long
    while)

    Fixes bug 1180283

    Change-Id: I64252b30e2596812f3b84da64b1fc8681661d7f8