Here's one extreme example. In the original data model, the password
isn't encrypted. In the new one, it is.

On Sep 22, 4:41 am, Tim Hoffman <[email protected]> wrote:
> Why can't you push the version 2, start updating the data
> but still keep running version 1 until the data update has finished.
>
> That I believe is the normal recommended approach.
>
> Is there something about your new version 2 data model that will break
> version 1 ?
>
> T
>
> On Sep 21, 2:29 am, Kyle Baley <[email protected]> wrote:
>
>
>
> > We've just released the first version of our application and are now
> > looking at a problem we've been avoiding until now. Namely, what is
> > the best way to upgrade the application to a new version that requires
> > changes to the datastore. We're looking at two options:
>
> > 1) Big Bang Upgrade
> > We take the application down and run an upgrade process to update all
> > entities from version 1 to version 2.
>
> > Pros: Easy to maintain; intuitive
> > Cons: App has to be taken down for a period of time, which will
> > increase as time passes and more data is added to the datastore
> > (potentially hitting the limit for long-running processes eventually)
> > Question: What's a good way to take the app offline?
>
> > 2) Version Entities Individually
> > Each entity has a version number and we have a series of commands,
> > each one responsible for upgrading an entity from one version to the
> > next. As we request entities, we check to see if it's the latest
> > version. If not, we run each necessary upgrade command in sequence
> > until it is the latest version.
>
> > Pros: No need to take the app offline; provides flexibility on whether
> > to upgrade everything at once or piecemeal
> > Cons: Not as intuitive; entities with different versions in the
> > datastore (if that matters)
>
> > What do other people do to upgrade their datastore for a live
> > application?

-- 
You received this message because you are subscribed to the Google Groups 
"Google App Engine" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/google-appengine?hl=en.

Reply via email to