[APIM] Autoscaling and AZ

Author: dlepow

articles/api-management/api-management-howto-autoscale.md

@@ -1,17 +1,14 @@
 ---
 # Mandatory fields. See more on aka.ms/skyeye/meta.
 title: Configure autoscale of an Azure API Management instance | Microsoft Docs
-description: This topic describes how to set up autoscale behavior for an Azure API Management instance.
+description: This article describes how to set up autoscale behavior for an Azure API Management instance.
 services: api-management
 documentationcenter: ''
 author: dlepow
-manager: anneta
-editor: ''
 
 ms.service: api-management
-ms.workload: integration
-ms.topic: article
-ms.date: 06/20/2018
+ms.topic: how-to
+ms.date: 02/02/2022
 ms.author: danlep
 ---
 
@@ -39,11 +36,11 @@ To follow the steps from this article, you must:
 
 Certain limitations and consequences of scaling decisions need to be considered before configuring autoscale behavior.
 
-+ Autoscale can be enabled only for **Standard** and **Premium** tiers of Azure API Management service.
-+ Pricing tiers also specify the maximum number of units for a service instance.
++ The pricing tier of your API Management instance determines the [maximum number of units](upgrade-and-scale.md#upgrade-and-scale) you may set in autoscale rules. The **Standard tier** can be scaled to 4 units. You can add any number of units to the **Premium** tier.
 + Scaling process will take at least 20 minutes.
-+ If the service is locked by another operation, scaling request will fail and retry automatically.
-+ In case of a service with multi-regional deployments, only units in the **Primary location** can be scaled. Units in other locations can't be scaled.
++ If the service is locked by another operation, the scaling request will fail and retry automatically.
++ If your service instance is deployed in multiple regions (locations), only units in the **Primary location** can be scaled. Units in other locations can't be scaled.
++ If your service instance is configured with [availability zones](zone-redundancy.md) in the **Primary location**, be aware of the number of zones when configuring autoscaling. The counts (API Management units) in autoscale rules and limits must be a multiple of the number of zones. 
 
 ## Enable and configure autoscale for Azure API Management service
 

articles/api-management/zone-redundancy.md

@@ -5,7 +5,7 @@ author: dlepow
 
 ms.service: api-management
 ms.topic: how-to
-ms.date: 01/24/2022
+ms.date: 02/02/2022
 ms.author: danlep
 ms.custom: references_regions
 
@@ -50,9 +50,12 @@ Configuring API Management for zone redundancy is currently supported in the fol
 
 ## Prerequisites
 
-* If you have not yet created an API Management service instance, see [Create an API Management service instance](get-started-create-service-instance.md). Select the Premium service tier.
+* If you haven't yet created an API Management service instance, see [Create an API Management service instance](get-started-create-service-instance.md). Select the Premium service tier.
 * If your API Management instance is deployed in a [virtual network](api-management-using-with-vnet.md), ensure that you set up a virtual network, subnet, and public IP address in any new location where you plan to enable zone redundancy.
 
+> [!NOTE]
+> If you've configured [autoscaling](api-management-howto-autoscale.md) for your API Management instance in the primary location, you might need to adjust your autoscale settings after enabling zone redundancy. The counts (API Management units) in autoscale rules and limits must be a multiple of the number of zones.
+
 ## Enable zone redundancy - portal
 
 In the portal, optionally enable zone redundancy when you add a location to your API Management service, or update the configuration of an existing location.
@@ -61,7 +64,7 @@ In the portal, optionally enable zone redundancy when you add a location to your
 1. Select an existing location, or select **+ Add** in the top bar. The location must [support availability zones](#supported-regions).
 1. Select the number of scale **[Units](upgrade-and-scale.md)** in the location.
 1. In **Availability zones**, select one or more zones. The number of units selected must distribute evenly across the availability zones. For example, if you selected 3 units, select 3 zones so that each zone hosts one unit.
-1. If the API Management instance is deployed in a [virtual network](api-management-using-with-vnet.md), configure virtual network settings in the location by select an existing virtual network, subnet, and public IP address that are available in the location. For an existing location, the virtual network and subnet must be configured from the Virtual Network blade.
+1. If the API Management instance is deployed in a [virtual network](api-management-using-with-vnet.md), select an existing virtual network, subnet, and public IP address that are available in the location. For an existing location, the virtual network and subnet must be configured from the Virtual Network blade.
 1. Select **Apply** and then select **Save**.
 
 :::image type="content" source="media/zone-redundancy/add-location-zones.png" alt-text="Enable zone redundancy":::