Merge pull request #111371 from jonels-msft/hsc-backup

Backup and restore

Author: American-Dipper

articles/postgresql/TOC.yml

@@ -167,6 +167,10 @@
         href: concepts-hyperscale-firewall-rules.md
       - name: Configure SSL
         href: concepts-hyperscale-ssl-connection-security.md
+    - name: Business continuity
+      items:
+      - name: Backup and restore
+        href: concepts-hyperscale-backup.md
     - name: Monitor and tune
       items:
       - name: Monitor and tune

articles/postgresql/concepts-hyperscale-backup.md

@@ -0,0 +1,91 @@
+---
+title: Backup and restore – Hyperscale (Citus) - Azure Database for PostgreSQL
+description: Protecting data from accidental corruption or deletion
+author: jonels-msft
+ms.author: jonels
+ms.service: postgresql
+ms.subservice: hyperscale-citus
+ms.topic: conceptual
+ms.date: 04/28/2020
+---
+
+# Backup and restore in Azure Database for PostgreSQL - Hyperscale (Citus)
+
+Azure Database for PostgreSQL – Hyperscale (Citus) automatically creates
+backups of each node and stores them in locally redundant storage. Backups can
+be used to restore your Hyperscale (Citus) cluster to a specified time. Backup
+and restore are an essential part of any business continuity strategy because
+they protect your data from accidental corruption or deletion.
+
+## Backups
+
+At least once a day, Azure Database for PostgreSQL takes snapshot backups of
+data files and the database transaction log. The backups allow you to restore a
+server to any point in time within the retention period. (The retention period
+is currently 35 days for all clusters.) All backups are encrypted using AES
+256-bit encryption.
+
+In Azure regions that support availability zones, backup snapshots are stored
+in three availability zones. As long as at least one availability zone is
+online, the Hyperscale (Citus) cluster is restorable.
+
+Backup files can't be exported. They may only be used for restore operations
+in Azure Database for PostgreSQL.
+
+### Backup storage cost
+
+For current backup storage pricing, see the Azure Database for PostgreSQL -
+Hyperscale (Citus) [pricing
+page](https://azure.microsoft.com/pricing/details/postgresql/hyperscale-citus/).
+
+## Restore
+
+In Azure Database for PostgreSQL, restoring a Hyperscale (Citus) cluster
+creates a new cluster from the original nodes' backups.
+
+> [!IMPORTANT]
+> Deleted Hyperscale (Citus) clusters can't be restored. If you delete the
+> cluster, all nodes that belong to the cluster are deleted and can't be
+> recovered. To protect cluster resources, post deployment, from accidental
+> deletion or unexpected changes, administrators can leverage [management
+> locks](/azure/azure-resource-manager/management/lock-resources).
+
+### Point-in-time restore (PITR)
+
+You can restore a cluster to any point in time within the last 35 days.
+Point-in-time restore is useful in multiple scenarios. For example, when a user
+accidentally deletes data, drops an important table or database, or if an
+application accidentally overwrites good data with bad data.
+
+The restore process creates a new cluster in the same Azure region,
+subscription, and resource group as the original. The cluster has the
+original's configuration: the same number of nodes, number of vCores, storage
+size, user roles, PostgreSQL version, and version of the Citus extension.
+
+Firewall settings and PostgreSQL server parameters are not preserved from the
+original server group, they are reset to default values. The firewall will
+prevent all connections. You will need to manually adjust these settings after
+restore.
+
+> [!IMPORTANT]
+> You'll need to open a support request to perform point-in-time restore of
+> your Hyperscale (Citus) cluster.
+
+### Post-restore tasks
+
+After a restore from either recovery mechanism, you should do the
+following to get your users and applications back up and running:
+
+* If the new server is meant to replace the original server, redirect clients
+  and client applications to the new server
+* Ensure appropriate server-level firewall and VNet rules are in place for
+  users to connect. These rules aren't copied from the original server group.
+* Adjust PostgreSQL server parameters as needed. The parameters aren't copied
+  from the original server group.
+* Ensure appropriate logins and database level permissions are in place
+* Configure alerts, as appropriate
+
+## Next steps
+
+* Learn about [Azure availability zones](/azure/availability-zones/az-overview).
+* Set [suggested alerts](/azure/postgresql/howto-hyperscale-alert-on-metric#suggested-alerts) on Hyperscale (Citus) server groups.