Merge pull request #291108 from dlepow/azlb

[APIM] Scale units in AZs behavior

Author: denrea

articles/api-management/high-availability.md

@@ -35,8 +35,7 @@ Enabling [zone redundancy](../reliability/migrate-api-mgt.md) for an API Managem
 
 When you enable zone redundancy in a region, consider the number of API Management scale [units](upgrade-and-scale.md) that need to be distributed. Minimally, configure the same number of units as the number of availability zones, or a multiple so that the units are distributed evenly across the zones. For example, if you select 3 availability zones in a region, you could have 3 units so that each zone hosts one unit.
 
-> [!NOTE]
-> Use [capacity metrics](api-management-capacity.md) and your own testing to decide the number of scale units that will provide the gateway performance for your needs. Learn more about [scaling and upgrading](upgrade-and-scale.md) your service instance.
+[!INCLUDE [api-management-az-notes](../../includes/api-management-az-notes.md)]
 
 ## Multi-region deployment
 

articles/reliability/migrate-api-mgt.md

@@ -44,7 +44,7 @@ There are no downtime requirements for any of the migration options.
 
 * When you're enabling availability zones in a region, you configure API Management scale [units](../api-management/upgrade-and-scale.md) that you can distribute evenly across the zones. For example, if you configure two zones, you can configure two units, four units, or another multiple of two units. 
 
-  Adding units incurs additional costs. For details, see [API Management pricing](https://azure.microsoft.com/pricing/details/api-management/).
+    [!INCLUDE [api-management-az-notes](../../includes/api-management-az-notes.md)]
 
 * If you configured autoscaling for your API Management instance in the primary location, you might need to adjust your autoscale settings after configuring availability zones. The number of API Management units in autoscale rules and limits must be a multiple of the number of zones.
 

includes/api-management-az-notes.md

@@ -0,0 +1,13 @@
+---
+author: dlepow
+ms.service: azure-api-management
+ms.topic: include
+ms.date: 11/26/2024
+ms.author: danlep
+---
+
+> [!NOTE]
+> Use [capacity metrics](../articles/api-management/api-management-capacity.md) and your own testing to decide the number of scale units that will provide the gateway performance for your needs. Adding units incurs additional costs. Learn more about [scaling and upgrading](../articles/api-management/upgrade-and-scale.md) your service instance.
+    
+> [!NOTE]
+> When availability zones are configured for your API Management instance, under normal operating conditions all scale units in all configured zones are active and serve gateway traffic.