Merge pull request #202078 from sr-msft/fspg-ha-same-zone-3

FSPG: HA same zone further updates

Author: hmacgregor1

articles/postgresql/flexible-server/concepts-high-availability.md

@@ -169,15 +169,15 @@ Flexible servers that are configured with high availability, log data is replica
   2. If you just want to restore an object, you can then export the object from the restored database server and import it to your production database server.
   3. If you want to clone your database server for testing and development purposes, or you want to restore for any other purposes, you can perform point-in-time restore.
 
-## Zone redundant high availability - features
+## High availability - features
 
 * Standby replica will be deployed in an exact VM configuration same as the primary server, including vCores, storage, network settings (VNET, Firewall), etc.
 
 * You can add high availability for an existing database server.
 
 * You can remove standby replica by disabling high availability.
 
-* You can only choose your availability zone for your primary database server. Standby zone is auto-selected.
+* For zone-redundant HA, you can choose your availability zones for your primary and standby database servers.
 
 * Operations such as stop, start, and restart are performed on both primary and standby database servers at the same time.
 
@@ -191,11 +191,11 @@ Flexible servers that are configured with high availability, log data is replica
 
 * Periodic maintenance activities such as minor version upgrades happen at the standby first and the service is failed over to reduce downtime.  
 
-## Zone redundant high availability - limitations
+## High availability - limitations
 
 * High availability is not supported with burstable compute tier.
 * High availability is supported only in regions where multiple zones are available.
-* Due to synchronous replication to another availability zone, applications can experience elevated write and commit latency.
+* Due to synchronous replication to the standby server, especially with zone-redundant HA, applications can experience elevated write and commit latency.
 
 * Standby replica cannot be used for read queries.
 
@@ -212,7 +212,7 @@ Flexible servers that are configured with high availability, log data is replica
 
 * If logical decoding or logical replication is configured with a HA configured flexible server, in the event of a failover to the standby server, the logical replication slots are not copied over to the standby server.  
 
-## Availability without high availability
+## Availability for non-HA servers
 
 For Flexible servers configured **without** high availability, the service still provides built-in availability, storage redundancy and resiliency to help to recover from any planned or unplanned downtime events.
 
@@ -257,7 +257,7 @@ Here are some failure scenarios that require user action to recover:
 
 * **Can I choose the availability zones for my primary and standby servers?** <br>
     If you choose same zone HA, then you can only choose the primary server. If you choose zone redundant HA, then you can choose both primary and standby AZs.
-    
+
 * **Is zone redundant HA available in all regions?** <br>
     Zone-redundant HA is available in regions that support multiple AZs in the region. For the latest region support, please see [this documentation](overview.md#azure-regions). We are continuously adding more regions and enabling multiple AZs. Note that same-zone HA is available in all regions. 
 

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

@@ -11,7 +11,7 @@ ms.date: 11/30/2021
 
 # Limits in Azure Database for PostgreSQL - Flexible Server
 
-[!INCLUDE [!INCLUDE [applies-to-postgresql-flexible-server](../includes/applies-to-postgresql-flexible-server.md)]
+[!INCLUDE [applies-to-postgresql-flexible-server](../includes/applies-to-postgresql-flexible-server.md)]
 
 The following sections describe capacity and functional limits in the database service. If you'd like to learn about resource (compute, memory, storage) tiers, see the [compute and storage](concepts-compute-storage.md) article.
 
@@ -46,7 +46,7 @@ When connections exceed the limit, you may receive the following error:
 > FATAL:  sorry, too many clients already.
 
 > [!IMPORTANT]
-> For best experience, we recommend that you use a connection pool manager like PgBouncer to efficiently manage connections. Azure Database for PostgreSQL - Flexible Server offers pgBouncer as [built-in connection pool management solution](concepts-pgbouncer.md). 
+> For best experience, it is recommended to you use a connection pool manager like PgBouncer to efficiently manage connections. Azure Database for PostgreSQL - Flexible Server offers pgBouncer as [built-in connection pool management solution](concepts-pgbouncer.md). 
 
 A PostgreSQL connection, even idle, can occupy about 10 MB of memory. Also, creating new connections takes time. Most applications request many short-lived connections, which compounds this situation. The result is fewer resources available for your actual workload leading to decreased performance. Connection pooling can be used to decrease idle connections and reuse existing connections. To learn more, visit our [blog post](https://techcommunity.microsoft.com/t5/azure-database-for-postgresql/not-all-postgres-connection-pooling-is-equal/ba-p/825717).
 
@@ -64,60 +64,59 @@ A PostgreSQL connection, even idle, can occupy about 10 MB of memory. Also, crea
 
 ### Storage
 
-- Once configured, storage size cannot be reduced. You have to create a new server with desired storage size, perform manual [dump and restore](../howto-migrate-using-dump-and-restore.md) and migrate your database(s) to the new server.
-- Currently, storage auto-grow feature is not available. Please monitor the usage and increase the storage to a higher size. 
+- Once configured, storage size can't be reduced. You have to create a new server with desired storage size, perform manual [dump and restore](../howto-migrate-using-dump-and-restore.md) and migrate your database(s) to the new server.
+- Currently, storage auto-grow feature isn't available. You can monitor the usage and increase the storage to a higher size. 
 - When the storage usage reaches 95% or if the available capacity is less than 5 GiB, the server is automatically switched to **read-only mode** to avoid errors associated with disk-full situations. 
 - We recommend to set alert rules for `storage used` or `storage percent` when they exceed certain thresholds so that you can proactively take action such as increasing the storage size. For example, you can set an alert if the storage percent exceeds 80% usage.
 
 ### Networking
 
 - Moving in and out of VNET is currently not supported.
 - Combining public access with deployment within a VNET is currently not supported.
-- Firewall rules are not supported on VNET, Network security groups can be used instead.
-- Public access database servers can connect to public internet, for example through `postgres_fdw`, and this access cannot be restricted. VNET-based servers can have restricted outbound access using Network Security Groups.
+- Firewall rules aren't supported on VNET, Network security groups can be used instead.
+- Public access database servers can connect to public internet, for example through `postgres_fdw`, and this access can't be restricted. VNET-based servers can have restricted outbound access using Network Security Groups.
 
 ### High availability (HA)
 
-- Please see [Zone Redundant HA Limitations documentation](concepts-high-availability.md#zone-redundant-high-availability---limitations) page.
+- See [HA Limitations documentation](concepts-high-availability.md#high-availability---limitations).
 
 ### Availability zones
 
 - Manually moving servers to a different availability zone is currently not supported.
-- The availability zone of the HA standby server cannot be manually configured.
 
 ### Postgres engine, extensions, and PgBouncer
 
-- Postgres 10 and older are not supported. We recommend using the [Single Server](../overview-single-server.md) option if you require older Postgres versions.
+- Postgres 10 and older aren't supported. We recommend using the [Single Server](../overview-single-server.md) option if you require older Postgres versions.
 - Extension support is currently limited to the Postgres `contrib` extensions.
 - Built-in PgBouncer connection pooler is currently not available for Burstable servers.
-- SCRAM authentication is not supported with connectivity using built-in PgBouncer.
+- SCRAM authentication isn't supported with connectivity using built-in PgBouncer.
 
 ### Stop/start operation
 
 - Server can't be stopped for more than seven days.
 
 ### Scheduled maintenance
 
-- Changing the maintenance window less than five days before an already planned upgrade, will not affect that upgrade. Changes only take effect with the next scheduled maintenance.
+- Changing the maintenance window less than five days before an already planned upgrade, won't affect that upgrade. Changes only take effect with the next scheduled maintenance.
 
 ### Backing up a server
 
 - Backups are managed by the system, there is currently no way to run these backups manually. We recommend using `pg_dump` instead.
-- Backups are always snapshot-based full backups (not differential backups), possibly leading to higher backup storage utilization. Note that transaction logs (write ahead logs - WAL) are separate from the full/differential backups, and are archived continuously.
+- Backups are always snapshot-based full backups (not differential backups), possibly leading to higher backup storage utilization. The transaction logs (write ahead logs - WAL) are separate from the full/differential backups, and are archived continuously.
 
 ### Restoring a server
 
 - When using the Point-in-time-Restore feature, the new server is created with the same compute and storage configurations as the server it is based on.
 - VNET based database servers are restored into the same VNET when you restore from a backup.
-- The new server created during a restore does not have the firewall rules that existed on the original server. Firewall rules need to be created separately for the new server.
-- Restoring a deleted server is not supported.
-- Cross region restore is not supported.
+- The new server created during a restore doesn't have the firewall rules that existed on the original server. Firewall rules need to be created separately for the new server.
+- Restoring a deleted server isn't supported.
+- Cross region restore isn't supported.
 
 ### Other features
 
-* Azure AD authentication is not yet supported. We recommend using the [Single Server](../overview-single-server.md) option if you require Azure AD authentication.
-* Read replicas are not yet supported. We recommend using the [Single Server](../overview-single-server.md) option if you require read replicas.
-* Moving resources to another subscription is not supported. 
+* Azure AD authentication isn't yet supported. We recommend using the [Single Server](../overview-single-server.md) option if you require Azure AD authentication.
+* Read replicas aren't yet supported. We recommend using the [Single Server](../overview-single-server.md) option if you require read replicas.
+* Moving resources to another subscription isn't supported. 
 
 
 ## Next steps