Migrate to Git

Last modified: November 18, 2024

Introduction

Scrum Masters can migrate apps from SVN version control system to Git. For more information on version control, see Version Control in the Studio Pro Guide.

Git is a more modern version control system that has several advantages over SVN. For more information, see Version Control FAQ.

If your main line is Studio Pro version 9.24.28 or above and your team role is Scrum Master, you see a notification on a possible migration at the top of the Team Server page for your app. Click Migrate to Git to check for migration eligibility and to start the migration.

Apps Eligible for Migration

Only a user with the Scrum Master role can migrate an app. For more information, see App Roles.

To migrate to Git your app needs to meet several criteria. The automatic eligibility check validates whether your app meets the criteria mentioned below, and checks your SVN repository on certain technical aspects such as Git branch naming conventions. The check can take a couple of minutes, depending on the size of your repository.

The following criteria determine whether your app can be migrated to Git:

The main line (‘main’) branch in the app is Studio Pro version 9.24.28 or above
All branches in the app are Studio Pro version 9.12 or above
Current version control is in Team Server SVN
The size of the mpr file for the latest revision is smaller than 400 MB

In addition to the hard criteria mentioned above, a check is performed to determine whether your version control history can be migrated. To qualify for migrating your history, the size of your full SVN repository should be smaller than 3.5 GB.

Eligibility Check Outcomes

Not Eligible for Migration

If your app is not eligible for migration the reason(s) will be listed on the page. to continue with the migration, resolve these reasons and try again.

In case there are reasons you cannot address, please reach out to Support or your Customer Success Manager to discuss the options.

Eligible for Migrating Without History

If your app is eligible for migration, but the SVN repository size exceeds the threshold, you can only migrate the latest commit of the main branch. This limitation has been imposed to guarantee a smooth experience post-migration, as a large Git Repository Size can have a negative effect on the developer experience.

You will receive a full backup of your SVN repository after completing the migration.

Eligible for Migrating With History

If your repository is eligible for migrating with full history, you can choose whether to retain your history when migrating or not. For the smoothest experience post-migration we advise you to migrate without history.

How Migration Works

If you choose to continue, your app will permanently be migrated to Git and this will not be reversible. The process differs for migrating with or without your history. For more information, see Migrating Without History and Migrating With History sections below.

Access to SVN is disabled as soon as migration starts to prevent developers from making changes to SVN that will not be copied. If migration fails for any reason, it is rolled back and the access to SVN is restored.

To inform your team members about the process, two emails are sent out automatically:

Migration started
Migration completed or migration failed

These emails give brief information about the stage and emphasize that changes made during migration will be lost, since they cannot be committed to SVN anymore.

Migrating Without History

During migration without history, only the last revision of the main branch is copied from SVN to Git.

The migration should take a few minutes to complete.

After migration is completed a full backup of your SVN repository is created and made available to all Scrum Masters. They receive an email with information on how to download the backup that is available for three months. Several days before this backup expires all Scrum Masters on the app receive another email.

Inform your team members that they should commit their changes and merge them to the main line before starting the migration.

All work not merged to the main branch will not be migrated to your Git repository.

Migrating With History

During migration with history, all app history, including revisions for all branches, is copied from SVN to Git.

Depending on the size of your repository, the migration can take several hours to complete. If you have a large number of commits, Mendix recommends doing this when developers do not need access to the repository, for example during the night.

Inform your team members that they should commit their changes before starting the migration.

Previously deleted SVN branches will not be mapped to Git branches by the migration process and will be permanently removed. If the deleted SVN branch has not been merged to another branch beforehand, commits belonging to the deleted SVN branch will also be permanently removed.

Steps After Migration

After migration, existing local copies are no longer linked to a working version control system. To be able to work on your app and store your changes in the version control system, you need to check out (re-download) the app from Team Server. Do the following:

Open Studio Pro, then select the app that was migrated to Git. You can identify it by its Git icon. Click Open in Studio Pro to download the Git version of your app. Once this is completed you can make changes and store them in version control.
Remove previous local copies of the app to avoid working on the wrong app version.

If Migration Failed

If the migration process failed, all changes are rolled back. This means access to SVN is restored and you can keep developing your app. You can check common causes of a failed migration below and resolve them. After that you can attempt to migrate your app again.

The most likely reason your migration has failed is that you have branches that are invalid: they are below Mendix 9.12. To resolve this, delete or upgrade these branches.