Implement Data Redundancy – The Storage of Data

1. Log in to the Azure portal at https://portal.azure.com ➢ navigate to the Azure Synapse Analytics workspace you created in Exercise 3.3 ➢ choose the SQL Pools link from the left navigation menu in the Analytics Pools section ➢ and then select the dedicated SQL pool you created for Exercise 3.7. Something similar to Figure 4.8 is rendered.

FIGURE 4.8 Data redundancy dedicated SQL pool

2. Choose the Restore menu option on the SQL Pool blade (see Figure 4.8) ➢ enter a dedicated SQL pool name to apply the snapshot to (see Figure 4.9) ➢ select the Review + Restore button ➢ review the details ➢ and then click Create.

FIGURE 4.9 Data redundancy restore dedicated SQL pool

The first option was to select either the Automatic Restore Points or User‐defined Restore Points radio button. Notice that the Newest Restore Point datetime in Figure 4.9 is the same as the one shown via the SQL query just provided and shown in Figure 4.7. So, you know there is a link between what you see when running the SQL query and the snapshot to be applied if this option is selected. It is also possible to select a previous snapshot and restore it from the portal blade shown in Figure 4.9. In addition to applying the newest snapshot (the default) or an older one, had you created a user‐defined snapshot, it would show in a drop‐down list box when the User‐defined Restore Points radio button is selected. To create a user‐defined restore point, simply choose the + New Restore Point menu item, shown in Figure 4.8, enter a name, and then click Apply. One last point is that the snapshot must be applied to a new dedicated SQL pool; it cannot be applied to the one it was taken from. This is a platform restriction and not something you can change.
There is also a similar capability available with ADLS where your data files are stored. By default, a feature called Enable Soft Delete for Blobs is enabled. It is configurable from the Data Protection blade for the Azure storage account, as shown in Figure 4.10.

FIGURE 4.10 Data redundancy restore ADLS
At the time of writing, it is not possible to recover a single file, only an entire container. When a container is deleted, it is considered a soft delete. That means it can be recovered up to the number of days configured, which is 7 by default. After that time expires, the container and its contents are permanently removed and cannot be recovered. To recover a container that has been deleted, toggle the Show Deleted Containers switch, as shown in Figure 4.11.

FIGURE 4.11 Data redundancy restore ADLS container
To recover a container, click it and, in the next blade, click Undelete. The container and all the files are then recovered and ready for use. There is ongoing work to make this work on a file basis. Until then, you may consider implementing a business continuity and disaster recovery (BCDR) solution.