You can recover the previous model after you accidentally upload the wrong model to a MDrivenServer by removing the accidental version from the server’s model-version history and downloading the remaining previous version into MDriven Designer.
Before you start
An upload replaces the model definition running on the server. This procedure recovers a previous model version retained in the server’s version history; it does not restore business data from a database backup.
For example, if version 12 was running, and you accidentally upload version 13 from the wrong Designer project, remove version 13. Version 12 can then be selected as current and downloaded.
- Work on the correct MDrivenServer and slot. In the steps below, the slot is
A0. - Identify the accidental upload before deleting anything. Use the version list’s available information, such as its position and upload information, to distinguish it from the version you want to keep.
- If you need to restore application data as well as the model, follow Documentation:MDriven Backup & Restore Guide after restoring the model. Database snapshots are described in Documentation:Database download and upload.
Recover the previous model
- Sign in to the MDriven Portal and obtain the password for the target MDrivenServer.
- Select Visit MDrivenServer for that server.
- Sign in to MDrivenServer with user name
aand the password from the Portal. - Open the Admin area.
- Open Model Version Administration.
- Select slot
A0. - In the version list, locate the model version that you accidentally uploaded.
- Select that accidental version by clicking the green checkmark on its row, then delete it.
MDrivenServer keeps eight models in this version log. After deleting the accidental upload, the preceding retained version is available to download.
Set the recovered version as current
If the deleted version was the current version, deleting it leaves the application with no active model version. Stop the application before selecting the recovered version.
- Stop the application.
- In Model Version Administration, select the model version you want to run in the CurrentVersion combo box.
- Start the application again.
- Confirm that the intended version is current before continuing.
For example, after deleting accidental version 13, select version 12 in CurrentVersion, then restart the application. Do not restart the application until a retained version is selected.
Download the recovered model
- Return to MDriven Designer.
- Connect MDriven Designer to the same MDrivenServer and slot.
- Choose download model.
- Save the downloaded model before making further changes.
The downloaded model is the current retained server version. Review it in MDriven Designer before uploading any new change.
Database effect of model uploads
A model upload can have different database effects depending on whether the server already has a model:
| Server state before upload | Result described by MDrivenServer |
|---|---|
| No models in the version list | The upload recreates the database. |
| A model already exists | The database is evolved (changed) for the uploaded model. |
Recovering a prior model version does not by itself roll back database changes or restore deleted or changed business data. Create restore points before upgrades and model uploads, as described in Documentation:MDriven Backup & Restore Guide.
Prevent another accidental upload
Before uploading, verify which MDrivenServer and slot MDriven Designer is connected to. If the server is used for production or another environment that must be protected, enable the optional two-factor verification for model upload in MDrivenServer. The server displays a short upload verification code; the code changes after an upload and expires after a short time. This adds a deliberate confirmation step and identifies the server during upload. See the two-factor model-upload walkthrough.
If recovery is not possible
If the version you need is no longer among the eight retained versions, recover from a model copy or backup that you created earlier. If the issue is an Unknown valuetype error rather than an accidental model upload, use Documentation:Unknown valuetype instead of deleting model versions.