Backup and restore

When maintaining a sensenet repository, it is important to have a backup of your content. This article describes how to create a backup of the repository and how to restore it if needed.

Backup

Backing up the repository means creating a copy of the following things:

1. index
2. database

Technically the database would be enough as it contains all the information to build a completely new index - but this is not recommended. It is much faster to restore the index from a backup than to rebuild it from the database: in case of a huge repository this can take hours and recommended only in case an index backup is not available or corrupt.

The order is important: first you need to backup the index, then the database. If you do it the other way around, the content operations that happen between the two backups will not be included in the db backup and may lead to a corrupt index.

Depending on the load on your site and the time gap between the db and index backups, there may be a difference between the content in the database and the index. This is normal and next time you start the site after a restore, the index will catch up and will be extended with the missing index documents automatically.

Backup the index

sensenet is able to work with a local index, or in a network load balanced environment with multiple web nodes and a central search service. The backup process is different in these two cases.

Local index

In case of a local index you need to backup the index folder manually. This requires stopping the repository app first, then copying the index folder to a safe place. The index folder is located in the App_Data folder of the site.

Stopping the site is important so that the index does not change while you are copying it. If you do not stop the site, the index may become corrupt and you will not be able to restore it.

Search service index

In this more advanced architecture there is a central search service that maintains the index. We offer an OData REST API in the repository for starting and monitoring index backup operations in this scenario. You can call the following actions on the /Root content:

• BackupIndex: starts a backup operation. Calling it multiple times while a backup is still running will not create multiple backups, it will just return the status of the running backup.
• QueryIndexBackup: returns the status of the running backup operation and a history of past operations.
• CancelIndexBackup: cancels a running backup operation.

Backup the database

sensenet does not have a dedicated API or tool for creating a database backup. You can use any tool that is capable of creating a backup of a SQL Server database.

Restore

When you have a backup of the index and the database, you can restore the repository to the state it was in when you created the backup. In contrast to the backup process, the repository should be stopped (all web apps) during the restore process.

Restoring the database works the same way as in any other SQL Server database. You can use any tool that is capable of restoring a SQL Server database.

Restoring the index means copying the index folder back to the App_Data folder where it was backed up from. In case of a local index this means all web app instances, not just the backup source. In case of a search service index, you need to copy the index folder to the App_Data folder of the search service.

After restoring these components you can restart the site. If there was a huge time gap between the index and database backups, the index will need some time to catch up with the database.

Restoring without an index

If you only have a database backup, you can still restore the repository. In this case the index will be rebuilt from the database. This is a much slower process than restoring the index from a backup, but it is still possible. Just start the site with an empty index folder and the index will be rebuilt automatically.

This is not recommended for huge repositories as it can take hours to rebuild the index from the database.