Merge pull request #262423 from varun-dhawan/varund-july

[PostgreSQL] updates the details for maintenance

Author: v-regandowner

articles/postgresql/flexible-server/concepts-maintenance.md

@@ -7,16 +7,18 @@ ms.topic: conceptual
 author: varun-dhawan
 ms.author: varundhawan
 ms.reviewer: 
-ms.date: 7/25/2023
+ms.date: 1/4/2024
 ---
 
 # Scheduled maintenance in Azure Database for PostgreSQL – Flexible Server
 
 [!INCLUDE [applies-to-postgresql-flexible-server](../includes/applies-to-postgresql-flexible-server.md)]
 
 Azure Database for PostgreSQL - Flexible Server performs periodic maintenance to keep your managed database secure, stable, and up-to-date. During maintenance, the server gets new features, updates, and patches.
- 
-## Selecting a maintenance window
+ > [!IMPORTANT]
+> Please avoid all server operations (modifications, configuration changes, starting/stopping server) during Azure Database for PostgreSQL flexible server maintenance. Engaging in these activities can lead to unpredictable outcomes, possibly affecting server performance and stability. Wait until maintenance concludes before conducting server operations.
+
+## Select a maintenance window
 
 You can schedule maintenance during a specific day of the week and a time window within that day. Or you can let the system pick a day and a time window time for you automatically. Either way, the system alerts you five days before running any maintenance. The system will also let you know when maintenance is started, and when it's successfully completed.
 
@@ -37,11 +39,17 @@ When specifying preferences for the maintenance schedule, you can pick a day of
 
 You can update scheduling settings at any time. If there's maintenance scheduled for your flexible server and you update scheduling preferences, the current rollout proceeds as scheduled and the scheduling settings change will become effective upon its successful completion for the next scheduled maintenance.
 
-You can define system-managed schedule or custom schedule for each flexible server in your Azure subscription.  
+## System / Custom managed maintenance schedule
+
+You can define system-managed schedule or custom schedule for each flexible server in your Azure subscription:
+ 
 * With custom schedule, you can specify your maintenance window for the server by choosing the day of the week and a one-hour time window.  
-* With system-managed schedule, the system picks any one-hour window between 11pm and 7am in your server's region time.  
+* With system-managed schedule, the system will pick any one-hour window between 11pm and 7am in your server's region time.  
+
+> [!IMPORTANT]
+> A 7-day deployment gap between system-managed and custom-managed schedules was maintained.
 
-As part of rolling out changes, we apply the updates to the servers configured with system-managed schedule first followed by servers with custom schedule after a minimum gap of 7-days within a given region. If you intend to receive early updates on fleet of development and test environment servers, we recommend you configure system-managed schedule for servers used in development and test environment. This allows you to receive the latest update first in your Dev/Test environment for testing and evaluation for validation. If you encounter any behavior or breaking changes, you'll have time to address them before the same update is rolled out to production servers with custom-managed schedule. The update starts to roll out on custom-schedule flexible servers after seven days and is applied to your server at the defined maintenance window. At this time, there's no option to defer the update after the notification has been sent. Custom-schedule is recommended for production environments only. 
+Updates are first applied to servers with system-managed schedules, followed by those with custom schedules after at least 7 days within a region. To receive early updates for development and test servers, use a system-managed schedule. This allows early testing and issue resolution before updates reach production servers with custom schedules. Updates for custom-schedule servers begin 7 days later during a defined maintenance window. Once notified, updates can't be deferred. Custom schedules are advised for production environments only.
 
 In rare cases, maintenance event can be canceled by the system or may fail to complete successfully. If the update fails, the update is reverted, and the previous version of the binaries is restored. In such failed update scenarios, you may still experience restart of the server during the maintenance window. If the update is canceled or failed, the system creates a notification about canceled or failed maintenance event respectively notifying you. The next attempt to perform maintenance will be scheduled as per your current scheduling settings and you'll receive notification about it five days in advance.