There's actually a version tracked in the modello metadata database
table for this purpose already.
The tricky part is how to do the conversion - that seems to need to be
done outside of modello because of the complexity of having multiple
versions (see what it did to the data management :) I think if you
init normally, but don't load any data, then check that table for the
right version, you can decide to upgrade it before loading any data.
You'll need to lock the store accesses while that occurs. I expect
we'd use some other migration tool like has been discussed recently
for the task.
- Brett
On 19/11/2008, at 12:19 AM, Napoleon Esmundo C. Ramirez wrote:
Hello everyone,
Deng and I talked about putting a database compatibility check. I
filed
CONTINUUM-1980 to track this new feature. In summary, it states that
Continuum should be able to detect when it has been started with an
incompatible database and prompt the user to take the appropriate
action.
This should work transparently if all goes well, and will just display
recommendations in the UI if any problem occurred.
By intent, the checking should take place before the database
connection is
initialized. But since the database connection happens during the
components' initialization, it is suggested that the JdoFactory for
the
continuum database be removed in the application.xml and is instead
replaced
with a wrapper component that initializes the database connection
explicitly--not on component initialization. This new component can
be used
by a database-checking interceptor in the webapp or it can be
applied to
other modules like the redback users database.
For now, aside from the new interceptor and component suggested to
be added
to continuum, the impact I can see is that the following will have
to point
to the new component:
- org.apache.maven.continuum.management.StoreUtilities
- org.apache.maven.continuum.management.JdoDataManagementTool
- org.apache.maven.continuum.management.LegacyJdoDataManagementTool
Currently, they require the the continuum JdoFactory:
/**
* @plexus.requirement role="org.codehaus.plexus.jdo.JdoFactory"
role-hint="continuum"
*/
But I think these components don't need the JdoFactory right away,
so I
think we can delay the initialization of the database connection
component
to give way to checking during startup.
What do you think? Any comments are greatly appreciated.
Cheers!
Nap
--
Brett Porter
[EMAIL PROTECTED]
http://blogs.exist.com/bporter/
