Question about OpenUpgrade migration process

[ypapouin]

Still in the process of migrating a database from 11.0 to 12.0 I just go an issue that made me asking for the migration process.

At the first attempt to migrate [A], I got an exception raised from UoM _check_category_reference_uniqueness because I had two entries set as reference for the same category.
After fixing the DB manualy, I made a new attempt to migrate [B], but a new exception is raised about a non existing column from the resource module pre-migration script.

After watching logs, I can see that the resource module has already been migrated during [A] (pre and post migration scripts are executed) and looking at the database schema, I can see that the column openupgrade_legacy_12_0_tz is already there.

So my question is :

• Does the migration process is made using transaction ?
• Why the resource module version has not been written during [A] since the exception is raised from another module migration (uom) ?

A: migrate-11-07_26__120_Upgrade_dec_database_to_OpenERP_Odoo_12_via_openupgrade.log
B: migrate-14-14_45__120_Upgrade_dec_database_to_OpenERP_Odoo_12_via_openupgrade.log

[pedrobaeza]

Always restart the migration from the beginning for avoiding such problems and the ones depicted in #1879

[ypapouin]

Thank you for answering me, I didn't have this issue on previous migrations (6.1->7.0->8.0->10.0->11.0) even after having to fix multiple database content issue using the try and retry naive iterative method, resuming was never an issue since once a module was migrated, its version was updated too and changes were committed to database.

I took a look on the loading script changes between 11.0 and 12.0

On 11.0 a commit is done after writing module latest_version and state attributes in the for loop
https://github.com/OCA/OpenUpgrade/blob/11.0/odoo/modules/loading.py#L265

On 12.0 this commit is done before writing these module attributes
https://github.com/OCA/OpenUpgrade/blob/12.0/odoo/modules/loading.py#L284

I can see a comment about unit tests and I understand why a commit is necessary first but I think a second commit should be done at the end of the for loop before the next iteration. What do you think about this ?

[pedrobaeza]

As said, you are not doing things properly because of the end migration scripts. Any way, if there's a code error in that process that can be improved, @StefanRijnhart and @MiquelRForgeFlow can comment that are the main participants in that code.

[StefanRijnhart]

Agreed with committing after the version number was written as well (so here: https://github.com/OCA/OpenUpgrade/blob/12.0/odoo/modules/loading.py#L305). Will you file a PR?

[pedrobaeza]

I insist that resuming migration doesn't serve due to #1879, but it's good to fix the code any way.

[ypapouin]

I insist that resuming migration doesn't serve due to #1879, but it's good to fix the code any way.

I agree with you and since odoo closed (cancelled ?) this POC, does OpenUpgrade should add a migration_state column to module table in order to resume a migration and execute end correctly ?

[StefanRijnhart]

Yes, that would be the best thing, so if you could file a PR for that even better!