DOC-4307 Create DB availability placeholder article

Author: rrelledge

content/operate/rs/databases/durability-ha/db-availability.md

@@ -0,0 +1,40 @@
+---
+alwaysopen: false
+categories:
+- docs
+- operate
+- rs
+db_type: database
+description: Verify if a Redis Software database is available to perform read and write operations and can respond to queries from client applications.
+linkTitle: Database availability
+title: Check database availability
+toc: 'true'
+weight: 30
+---
+
+You can use the [database availability API]({{<relref "/operate/rs/references/rest-api/requests/bdbs/availability">}}) to verify whether a Redis Software database is available to perform read and write operations and can respond to queries from client applications. Load balancers and automated monitoring tools can use this API to monitor database availability.
+
+## Availability by database status
+
+| Database status | Availability |
+|-----------------|--------------|
+| active          | <span title="Available">&#x2705;</span> Available |
+| active-change-pending | <span title="Available">&#x2705;</span> Available |
+| creation-failed | <span title="Not available">:x:</span> Not available |
+| delete-pending  | <span title="Availability not guaranteed" class="font-serif">:warning:</span> Availability not guaranteed |
+| import-pending  | <span title="Available">&#x2705;</span> Available |
+| pending         | <span title="Available">&#x2705;</span> Available |
+| recovery        | <span title="Not available">:x:</span> Not available |
+
+## Availability by shard status
+ 
+| Shard status | Availability |
+|--------------|--------------|
+| busy         | <span title="Available">&#x2705;</span> Available |
+| down         | <span title="Not available">:x:</span> Not available |
+| importing    | <span title="Available">&#x2705;</span> Available |
+| loading      | <span title="Available">&#x2705;</span> Available |
+| ok           | <span title="Available">&#x2705;</span> Available |
+| timeout      | ?            |
+| trimming     | <span title="Available">&#x2705;</span> Available |
+| unknown      | ?            |