docs(SDB): add planned maintenance doc MTA-4837 (#3456)

* docs(SDB): add planned maintenance doc MTA-4837

* docs(SDB): update

* Update serverless/sql-databases/reference-content/planned-maintenance.mdx

Co-authored-by: nerda-codes <[email protected]>

* Apply suggestions from code review

Co-authored-by: nerda-codes <[email protected]>
Co-authored-by: fpagny <[email protected]>

---------

Co-authored-by: nerda-codes <[email protected]>
Co-authored-by: fpagny <[email protected]>

Author: 3 people

menu/navigation.json

@@ -3526,6 +3526,10 @@
                   {
                     "label": "Serverless SQL Databases overview",
                     "slug": "serverless-sql-databases-overview"
+                  },
+                  {
+                    "label": "Planned maintenance",
+                    "slug": "planned-maintenance"
                   }
                 ],
                 "label": "Additional Content",

serverless/sql-databases/reference-content/planned-maintenance.mdx

@@ -0,0 +1,46 @@
+---
+meta:
+  title: Maintenance process for Serverless SQL Databases
+  description: This page explains the maintenance process for Serverless SQL Databases and its potential impact on your applications
+content:
+  h1: Maintenance process for Serverless SQL Databases
+  paragraph: This page explains the maintenance process for Serverless SQL Databases and its potential impact on your applications
+tag: serverless sql databases maintenance service interruption planned operation
+dates:
+  validation: 2024-07-09
+  posted: 2024-07-09
+---
+
+## Overview
+
+To add features, deploy security fixes or corrective patches, we perform regular maintenance operations. **Most maintenance operations are transparent to you**, and have no impact on your database availability, or performance.
+
+However, **some maintenance operations may impact your database availability** or require actions on your side. In this case, **we will inform you beforehand**, so you can **follow the recommendations below** to ensure that the impact on your application is minimal.
+
+The maintenance operations particularly concern our [connection pooler](/serverless/sql-databases/reference-content/serverless-sql-databases-overview/) for now, as we are working on making it as transparent as possible in future Serverless SQL Databases updates.
+
+## Impact on your application and recommendations
+
+A maintenance operation impacting your SQL client connections to the database will usually:
+
+- Disconnect your SQL connections to the database **during less than 1 minute**
+
+- Require your **SQL client to reconnect afterward**
+
+To avoid requiring any manual actions on your side, **we recommend you ensure that your applications or SQL clients can reconnect automatically**. This is the default behavior with most web application frameworks or software relying on SQL Databases.
+
+<Message type="note">
+When the maintenance operation starts, database queries pending (such as transactions being processed) will still be processed before SQL clients are disconnected, as long as transactions do not last more than 1 minute.
+</Message>
+
+## Maintenance period and communication delay
+
+We will **communicate the maintenance period at least 1 week in advance** for low-impact operations, such as unavailability below 1 minute, and **up to 1 month in advance** for higher-impact operations.
+
+By default, we plan a maintenance period **every Tuesday between 14:30 pm and 14:45 pm (CEST)**, that disconnects SQL clients from your database **for at most 10 seconds**.
+
+Any change to this period or additional maintenance periods will be communicated specifically. 
+
+<Message type="note">
+If maintenance operations are urgent, such as security or corrective patches requiring immediate action, we may still perform maintenance operations without delay.
+</Message>