On Thu, 2016-03-24 at 10:45 +0000, stuart.mclaren at hp.com wrote: > I think this makes sense (helps us spot things which could impact upgrade). > > >Hi Glance Team, > > > >I have registered a blueprint [1] for blocking subtractive schema changes. > >Cinder and Nova are already supporting blocking of subtractive schema operations. Would like to add similar support here. > > > >Please let me know your opinion on the same. > > > >[1] https://blueprints.launchpad.net/glance/+spec/block-subtractive-operations > > > > > >Thank you, > > > >Abhishek Kekane You'll probably need some way to actually perform such migrations when needed. In Cinder we've introduced guidelines [1], which allow us to ALTER or DROP a column with a process stretching through 2-3 releases. Nova does a little better by not allowing nova-compute to access the DB (nova-conductor is acting as a proxy). Also note that unit test won't prevent you from all of the cases. It won't for example detect DB-specific migrations written in plain SQL as in [2]. [1] http://specs.openstack.org/openstack/cinder-specs/specs/mitaka/online-schema-upgrades.html [2] https://review.openstack.org/#/c/190300