Comment 4 for bug 1176142

Reviewed: https://review.openstack.org/43554
Committed: http://github.com/openstack/heat/commit/46ae6848896a24dece79771037b86cc6f4b53292
Submitter: Jenkins
Branch: master

commit 46ae6848896a24dece79771037b86cc6f4b53292
Author: Zane Bitter <email address hidden>
Date: Tue Aug 27 20:15:08 2013 +0200

    Implement interruption-free update and rollback

    During an update, where a resource must be replaced in its entirety, create
    the replacement resource before deleting the old resource.

    Also, allow rollback to the previous version of the resource without
    replacing it, where that is possible.

    Fixes bug #1176142

    Change-Id: Id89654bad297815bdbcc86f666367772889b5df4