opensearch btar

Author: wojcik-dorota

docs/platform/concepts/backup-to-another-region.md

@@ -5,6 +5,8 @@ sidebar_label: Backup to another region
 ---
 
 import RelatedPages from "@site/src/components/RelatedPages";
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
 
 In addition to the primary service backup, you can have a secondary backup in an alternative location.
 
@@ -27,6 +29,9 @@ BTAR is supported for the following services:
 
 ## How BTAR works
 
+<Tabs groupId="group1">
+<TabItem value="sql-relational" label="PostgreSQL & MySQL" default>
+
 When you enable the backup to another region (BTAR) feature, an additional service backup
 is created in the cloud region of your choice that is alternative to the primary backup
 location.
@@ -66,12 +71,66 @@ flowchart LR
             SBn
             end
         end
-    Service_X -- Default \n backups --> Primary_backups
-    Primary_backups -- Cross-region backups \n if BTAR  enabled --> Secondary_backups
-    Secondary_backups -- Secondary backups \n to restore service X --> Forked_service_X
-    Service_X -- Forking service X \n if primary region down --> Forked_service_X
+    Service_X -- Default backups --> Primary_backups
+    Primary_backups -- Cross-region backups<br/>if BTAR  enabled --> Secondary_backups
+    Secondary_backups -- Secondary backups<br/>to restore service X --> Forked_service_X
+    Service_X -- Forking service X<br/>if primary region down --> Forked_service_X
+```
+
+</TabItem>
+<TabItem value="non-sql-search-analytics" label="OpenSearch">
+
+When you enable the backup to another region (BTAR) feature:
+
+- An additional service backup is created in the cloud region of your choice that is
+  alternative to the primary backup location.
+- A custom repository is created for the additional region, where snapshots are managed in
+  sync with changes to snapshots in the primary region.
+
+Secondary backups are generated from primary backups, not from the service itself. For
+this reason, your secondary backup becomes available only after the primary backup is
+taken. There might be a data replication lag between the primary region and the secondary
+region.
+
+Restoring from a secondary backup, for example in case of an outage of the primary region,
+can be done by creating a fork of the service in the region where the secondary backup is
+located.
+
+```mermaid
+flowchart LR
+    subgraph Primary_region
+        direction TB
+        subgraph Service_X
+            end
+        subgraph Primary_backups
+            direction LR
+            PB1
+            PB2
+            PB3
+            PBn
+            end
+        end
+    subgraph Secondary_region
+        direction TB
+        subgraph Forked_service_X
+            end
+        subgraph Secondary_backups
+            direction LR
+            SB1
+            SB2
+            SB3
+            SBn
+            end
+        end
+    Service_X -- Default backups --> Primary_backups
+    Primary_backups -- Cross-region backups<br/>if BTAR  enabled --> Secondary_backups
+    Secondary_backups -- Secondary backups<br/>to restore service X --> Forked_service_X
+    Service_X -- Forking service X<br/>if primary region down --> Forked_service_X
 ```
 
+</TabItem>
+</Tabs>
+
 ## Limitations
 
 - BTAR is supported for Aiven for MySQL®, Aiven for PostgreSQL®, and Aiven for OpenSearch®.