Redis Snapshot and Restore

This feature allows you to take a snapshot of the data stored in the Redis server. The Redis server is an open-source, in-memory data storage that serves as a database, cache, or message broker. It stores a variety of data, including strings, lists, transaction data, datasets, geospatial index, and others.

The Redis server has a limited storage space. An internally configured purging activity periodically purges data from the Redis server. The data stored in the Redis server is used for analysis, comparison, and forecasting. To archive this historical data, the Vahana cloud provides a feature to take a snapshot of the Redis server’s data. This feature is called Redis Snapshot and Restore.

After you take a snapshot of the data, you can restore it in the future.

Use Case

In the real-world scenario, you can use the Logs Snapshot and Restore submodule as follows:

• Long-term log retention to optimize the data storage cost in the Elasticsearch server
• Retaining logs for ‘n’ number of years related to regulatory and compliance purposes
• Maintaining data for on-demand historical analysis
• Retaining snapshots for data migration between the dev, test, and production environments, and others

Concept

Accessing Redis Snapshot and Restore Submodule

You can access the Logs Snapshot and Restore submodule in the VRT-specific ITOps module. To access the Redis Snapshot and Restore module:

1. On the ITOps page, see the left panel.
2. In the left panel, click the VRT Ops menu to display a list of menu items.
3. In the list of menus, click Redis Snapshot and Restore to display the Redis Snapshot & Restore page.

Creating a New Snapshot

To take a backup of the Redis server’s data, you need to create a new snapshot. After you create a new snapshot, this function starts taking a backup of the data.

To create a new snapshot:

1. On the Redis Snapshot & Restore page, click Create New to display the Create Snapshot dialog box.
2. On the Create Snapshot dialog box, in the Description box, enter a brief reason to create the snapshot.
3. After you enter a description, click Create to create a new snapshot of the Redis server’s data.

After you successfully create a snapshot, the Redis Snapshot & Restore page displays its record in list format.

Errors in Creating a Snapshot

When you create a new snapshot of the Resid server’s data, you may encounter the following error types:

Error Type	Description
Snapshot cannot be created	This error occurs when a snapshot job is already taking place. After the Redis Snapshot submodule completes the current snapshot job, you can take a snapshot of the data.
Unable to create snapshot	This error occurs when the disk (hard disk) does not have sufficient space in the Redis server. To resolve this error, you need to delete the unused, old, and obsolete snapshots of data.
Unexpected System Error	This error occurs as a result of an unexpected error in the system. This unexpected error may occur in the code of the Redis Snapshot & Restore submodule or  because of network-related issues.
Snapshot Path Unavailable	This error occurs when a user attempts to delete the snap that is not available at the specific path or location. This error may also occur when a user restores a snapshot that is not available at the specific path or location.

Restore Snapshot

This feature allows you to restore the snapshot’s data for a specific usage. After you perform the restore function, it restores the snapshot’s data in the Redis server. After you restore the data, you can use it for analysis, comparison, and resolution purposes.

To restore the data:

1. On the Redis Snapshot & Restore page, under Name, find the snapshot that you want to restore.
2. After you find the snapshot, put the mouse pointer on its record and then move it to the right to find the three-dot icon ().
3. Click the three-dot icon (), and then click it to display a context menu.
4. In the context menu, click Restore to restore the snapshot’s data in the Redis server.