[Zope-dev] data migration from zope 2.6.1 to zope 2.7.0-b2

[Paul Winkler]

On Fri, Feb 06, 2004 at 03:12:39PM -0600, J Cameron Cooper wrote:
> altkey wrote:
> 
> >I am fairly new to zope & python but I am working to migrate some 
> >data/objects from zope 2.6.1 to zope 2.7.0-b2 (and eventually 2.7.0 
> >final.
> >
> >What I am doing is this.
> >    (1) get Dublin core metadata + some Dublin core extensions for the 
> >objects
> >    (2) get pure text representation of object content - I can't use  
> >a simple import/export in zexp format because the classes in the 
> >receiving zope instance differ significantly from the classes in the 
> >sending zope instance.
> >
> >I am able to collect all the data mentioned above and pass it across 
> >to the new 2.7.0-b2 zope instance but i am having trouble getting my 
> >objects to live where they need to live; specifically their path is 
> >not being accepted properly when i recreate the objects.
> 
> Before trying to deal with the problem you state, I'll make two possibly 
> simplifying observations:
> 
> 1. There should be no need to do any migration when upgrading Zope. The 
> ZODB has not changed, and you may simply copy it over or upgrade Zope in 
> place.
> 
> 2. ZSyncer is the best magic for copying objects from one instance to 
> another.

I doubt it will help. ZSyncer is a shortcut for export -> import,
and altkey wants to convert between two different classes.
Also zsyncer currently enforces (stupidly) that the two
zopes must have the same folder hierarchy - you can't
sync /foo/bar/baz to /bat/bar/baz.

altkey, maybe you should break this into multiple steps, some
of which are apparently done already;
something like:

1) write code that extracts data from an old class.

2) write code that creates an instance of the new class
from this data.

note that this is on one server so the classes must have
different names or live in different modules.
i think you're ok here already.

3) write a script that upgrades a single object "in place" by
doing #1, deleting the object, then doing #2

4) write a script that walks a folder tree and does #3
on all instances of the old class.

5) use zsyncer or export / import to copy the objects
from the old zope to the new zope.


-- 

Paul Winkler
http://www.slinkp.com
Look! Up in the sky! It's INMATE SUPER EXOSKELETON!
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