[openstack-dev] Work around DB in OpenStack (Oslo, Nova, Cinder, Glance)

Monty Taylor mordred at inaugust.com
Wed Jul 3 17:29:35 UTC 2013

On 07/03/2013 07:26 AM, Johannes Erdfelt wrote:
> On Wed, Jul 03, 2013, Michael Still <mikal at stillhq.com> wrote:
>> On Wed, Jul 3, 2013 at 3:50 AM, Boris Pavlovic <boris at pavlovic.me> wrote:
>>> Question:
>>>   Why we should put in oslo slqlalchemy-migrate monkey patches, when we are
>>> planing to switch to alembic?
>>> Answer:
>>>    If we don’t put in oslo sqlalchemy-migrate monkey patches. We won't be
>>> able to work on 7 point at all until 8 and 10 points will be implemented in
>>> every project. Also work around 8 point is not finished, so we are not able
>>> to implement 10 points in any of project. So this blocks almost all work in
>>> all projects. I think that these 100-200 lines of code are not so big price
>>> for saving few cycles of time.
>> We've talked in the past (Folsom summit?) about alembic, but I'm not
>> aware of anyone who is actually working on it. Is someone working on
>> moving us to alembic? If not, it seems unfair to block database work
>> on something no one is actually working on.
> I've started working on a non-alembic migration path that was discussed
> at the Grizzly summit.
> While alembic is better than sqlalchemy-migrate, it still requires long
> downtimes when some migrations are run. We discussed moving to an
> expand/contract cycle where migrations add new columns, allow migrations
> to slowly (relatively speaking) migrate data over, then (possibly) remove
> any old columns.

I think if you're working on a non-alembic plan and boris is working on
an alembic plan, then something is going to be unhappy in the
not-too-distant future. Can we get alignment on this?

More information about the OpenStack-dev mailing list