Merge pull request #289957 from flang-msft/Umang---fxl-Redis-OSS-tiers-Zone-Resiliency-default

Umang---fxl-Redis-OSS-tiers-Zone-Resiliency-default

Author: JamesJBarnett

articles/azure-cache-for-redis/cache-high-availability.md

@@ -20,7 +20,7 @@ Various high availability options are available in the Standard, Premium, and En
 | Option | Description | Availability | Standard | Premium | Enterprise |
 | ------------------- | ------- | ------- | :------: | :---: | :---: |
 | [Standard replication](#standard-replication-for-high-availability)| Dual-node replicated configuration in a single data center with automatic failover | 99.9% (see [details](https://azure.microsoft.com/support/legal/sla/cache/v1_1/)) |Yes|Yes|Yes|
-| [Zone redundancy](#zone-redundancy) | Multi-node replicated configuration across Availability Zones, with automatic failover | 99.9% in Premium; 99.99% in Enterprise (see [details](https://azure.microsoft.com/support/legal/sla/cache/v1_1/)) |Yes (Preview)|Yes|Yes|
+| [Zone redundancy](#zone-redundancy) | Multi-node replicated configuration across Availability Zones, with automatic failover | 99.9% in Premium; 99.99% in Enterprise (see [details](https://azure.microsoft.com/support/legal/sla/cache/v1_1/)) |Yes|Yes|Yes|
 | Geo-replication | Linked cache instances in two regions, with user-controlled failover | Premium; Enterprise (see [details](https://azure.microsoft.com/support/legal/sla/cache/v1_1/)) |No| [Passive](#passive-geo-replication) | [Active](#active-geo-replication) |
 | [Import/Export](#importexport) | Point-in-time snapshot of data in cache.  | 99.9% (see [details](https://azure.microsoft.com/support/legal/sla/cache/v1_1/)) |No|Yes|Yes|
 | [Persistence](#persistence) | Periodic data saving to storage account.  | 99.9% (see [details](https://azure.microsoft.com/support/legal/sla/cache/v1_1/)) |No|Yes|Preview|
@@ -61,19 +61,16 @@ Also, Azure Cache for Redis provides more replica nodes in the Premium tier. A [
 
 ## Zone redundancy
 
-Applicable tiers: **Standard (preview)**, **Premium**, **Enterprise**, **Enterprise Flash**
+Applicable tiers: **Standard**, **Premium**, **Enterprise**, **Enterprise Flash**
 
 Recommended for: **High availability**, **Disaster recovery - intra region**
 
-Azure Cache for Redis supports zone redundant configurations in the Standard (preview), Premium, and Enterprise tiers. A [zone redundant cache](cache-how-to-zone-redundancy.md) can place its nodes across different [Azure Availability Zones](../reliability/availability-zones-overview.md) in the same region. It eliminates data center or Availability Zone outage as a single point of failure and increases the overall availability of your cache.
-
-> [!NOTE]
-> On the Premium caches, only _automatic zone allocation_ is in public preview. Manual selection of availability zones us unchanged. Manual selection is GA (General Availability).
+Azure Cache for Redis supports zone redundant configurations in the Standard, Premium, and Enterprise tiers. A [zone redundant cache](cache-how-to-zone-redundancy.md) can place its nodes across different [Azure Availability Zones](../reliability/availability-zones-overview.md) in the same region. It eliminates data center or Availability Zone outage as a single point of failure and increases the overall availability of your cache.
 
 If a cache is configured to use two or more zones as described earlier in the article, the cache nodes are created in different zones. When a zone goes down, cache nodes in other zones are available to keep the cache functioning as usual.
 
 > [!IMPORTANT]
-> You can now enable _automatic zone allocation_ for all caches in applicable tiers and regions. For more information, see [Enable zone redundancy for Azure Cache for Redis](cache-how-to-zone-redundancy.md).
+> Azure Cache For Redis by default creates zone redundant caches for Premium, Standard Tiers using _Automatic_Zonal_Allocation_ in regions that support zones. For more information, see [Enable zone redundancy for Azure Cache for Redis](cache-how-to-zone-redundancy.md). 
 
 ### Premium tier
 
@@ -102,19 +99,21 @@ When a data node becomes unavailable or a network split happens, a failover simi
 
 ### Regional availability
 
-Zone-redundant Premium tier caches are available in the following regions:
+Zone-redundant Premium, Standard tier caches are available in the following regions:
 
 | Americas | Europe | Middle East | Africa | Asia Pacific |
 |---|---|---|---|---|
 | Brazil South | France Central | Qatar Central | South Africa North | Australia East |
-| Canada Central | Germany West Central | | | Central India |
-| Central US | North Europe | | | Japan East |
-| East US | Norway East | | | Korea Central |
-| East US 2 | UK South | | | Southeast Asia |
-| South Central US | West Europe | | | East Asia |
-| US Gov Virginia | Sweden Central | | | China North 3 |
-| West US 2 | Switzerland North | | | |
-| West US 3 | Poland Central | | | |
+| Canada Central | Italy North | UAE North | | Central India |
+| Central US |  Germany West Central | Israel Central | | Japan East |
+| East US | Norway East | | | |
+| East US 2 | North Europe  | | | Southeast Asia |
+| South Central US | UK South | | | East Asia |
+| US Gov Virginia | West Europe  | | | China North 3 |
+| West US 2 | Sweden Central | | |Korea Central  | 
+| West US 3 | Switzerland North | | | New Zealand North |
+| Mexico Central | Poland Central ||||
+||Spain Central ||||
 
 Zone-redundant Enterprise and Enterprise Flash tier caches are available in the following regions:
 

articles/azure-cache-for-redis/cache-how-to-geo-replication.md

@@ -6,7 +6,7 @@ description: Learn how to use cross-region replication to provide disaster recov
 
 ms.topic: how-to
 ms.custom: engagement-fy23
-ms.date: 12/15/2023
+ms.date: 11/15/2024
 
 ---
 
@@ -39,6 +39,7 @@ _Passive geo-replication_ is only available in the Premium tier of Azure Cache f
 To configure geo-replication between two caches, the following prerequisites must be met:
 
 - Both caches are [Premium tier](cache-overview.md#service-tiers) caches.
+- Both caches should have only one replica per primary per shard.
 - Both caches are in the same Azure subscription.
 - The secondary linked cache is either the same cache size or a larger cache size than the primary linked cache. To use geo-failover, both caches must be the same size.
 - Both caches are created and in a running state.
@@ -49,7 +50,6 @@ To configure geo-replication between two caches, the following prerequisites mus
 
 Some features aren't supported with geo-replication:
 
-- Zone Redundancy isn't supported with geo-replication.
 - Persistence isn't supported with geo-replication.
 - Caches with more than one replica can't be geo-replicated.
 - Clustering is supported if both caches have clustering enabled and have the same number of shards.

articles/azure-cache-for-redis/cache-how-to-zone-redundancy.md

@@ -5,14 +5,17 @@ description: Learn how to set up zone redundancy for your Premium and Enterprise
 
 
 ms.topic: conceptual
-ms.date: 08/05/2024
+ms.date: 11/15/2024
 
 ---
 
 # Enable zone redundancy for Azure Cache for Redis
 
 In this article, you learn how to configure a zone-redundant Azure Cache instance using the Azure portal.
 
+> [!NOTE]
+   > In regions that don't support zones, the option to enable zone redundancy is disabled. For a list of regions that support zones, see [Azure Cache for Redis - zones supported regions](cache-high-availability.md#regional-availability).
+
 Azure Cache for Redis Standard (preview), Premium, and Enterprise tiers provide built-in redundancy by hosting each cache on two dedicated virtual machines (VMs). Even though these VMs are located in separate [Azure fault and update domains](/azure/virtual-machines/availability) and highly available, they're susceptible to data center-level failures. Azure Cache for Redis also supports zone redundancy in its Standard (preview), Premium, and Enterprise tiers. A zone-redundant cache runs on VMs spread across multiple [Availability Zones](../reliability/availability-zones-overview.md). It provides higher resilience and availability.
 
 ## Prerequisites
@@ -27,57 +30,96 @@ To create a cache, follow these steps:
 
 1. On the **New** page, select **Databases** and then select **Azure Cache for Redis**.
 
-    :::image type="content" source="media/cache-create/new-cache-menu.png" alt-text="Select Azure Cache for Redis.":::
+   :::image type="content" source="media/cache-create/new-cache-menu.png" alt-text="Select Azure Cache for Redis.":::
 
 1. On the **Basics** page, configure the settings for your new cache.
 
     | Setting      | Suggested value  | Description |
     | ------------ |  ------- | -------------------------------------------------- |
     | **Subscription** | Select your subscription. | The subscription under which to create this new Azure Cache for Redis instance. |
     | **Resource group** | Select a resource group, or select **Create new** and enter a new resource group name. | Name for the resource group in which to create your cache and other resources. By putting all your app resources in one resource group, you can easily manage or delete them together. |
-    | **DNS name** | Enter a globally unique name. | The cache name must be a string between 1 and 63 characters that contains only numbers, letters, or hyphens. The name must start and end with a number or letter, and can't contain consecutive hyphens. Your cache instance's *host name* will be *\<DNS name>.redis.cache.windows.net*. |
+    | **DNS name** | Enter a globally unique name. | The cache name must be a string between 1 and 63 characters that contains only numbers, letters, or hyphens. The name must start and end with a number or letter, and can't contain consecutive hyphens. Your cache instance's _host name_ will be _\<DNS name>.redis.cache.windows.net_. |
     | **Location** | Select a location. | Select a [region](https://azure.microsoft.com/regions/) near other services that use your cache. |
     | **Cache type** | Select a [Premium or Enterprise tier](https://azure.microsoft.com/pricing/details/cache/) cache. |  The pricing tier determines the size, performance, and features that are available for the cache. For more information, see [Azure Cache for Redis Overview](cache-overview.md). |
 
-1. For Standard or Premium tier cache, select **Advanced** in the Resource menu. To enable zone resiliency with automatic zone allocation, select **(Preview) Select zones automatically**.
-
-    > [!NOTE]
-    > On the Premium caches, only _automatic zone selection_ is in public preview. Manual selection of availability zones us unchanged. Manual selection is GA (General Availability).
+1. **Standard** tier caches are always created as zone redundant using [Automatic Zonal Allocation](#automatic-zonal-allocation) in the [regions that support availability zones](cache-high-availability.md#regional-availability).
+    :::image type="content" source="media/cache-how-to-zone-redundancy/create-standard-cache-default-as-az.png" alt-text="Screenshot showing the Advanced tab with a red box around Availability zones for Standard cache.":::
 
-   :::image type="content" source="media/cache-how-to-zone-redundancy/cache-availability-zone.png" alt-text="Screenshot showing the Advanced tab with a red box around Availability zones.":::
+1. For **Premium** tier caches, select **Advanced** in the Resource menu. In regions that support zones, Zone redundancy for this tier can be enabled using couple of ways.
+    1. Using [Automatic Zonal Allocation](#automatic-zonal-allocation):
+        - **Allocate zones automatically** is the default option selected for **Availability Zones**.
+            :::image type="content" source="media/cache-how-to-zone-redundancy/create-premium-cache-default-as-az.png" alt-text="Screenshot showing the Advanced tab with a red box around Availability zones for Premium cache.":::
+    1. Using **UserDefined Zonal Allocation**:
+        - For **Premium** tier caches, **Availability zones** setting can be edited by the user, using which they can select non-zonal or manually select zones for the cache.
+   - Selecting NoZones:
+                :::image type="content" source="media/cache-how-to-zone-redundancy/create-premium-cache-as-non-az.png" alt-text="Screenshot showing the Advanced tab with a red box around Availability zones and its None option for Premium cache.":::
+   - When choosing zones manually, the number of availability zones must always be less than or equal to the total number of nodes for the cache:
+                 :::image type="content" source="media/cache-how-to-zone-redundancy/cache-premium-replica-count.png" alt-text="Screenshot showing Availability zones set to one and Replica count set to three.":::
 
-   For an Enterprise tier cache, select **Advanced** in the Resource menu. For **Zone redundancy**, select **Zone redundant (recommended)**.
+1. For an Enterprise tier cache, select **Advanced** in the Resource menu. For **Zone redundancy**, select **Zone redundant (recommended)**.
 
    :::image type="content" source="media/cache-how-to-zone-redundancy/cache-enterprise-create-zones.png" alt-text="Screenshot showing the Advanced tab with a red box around Zone redundancy.":::
 
-   Automatic zone allocation increases the overall availability of your cache by automatically spreading it across multiple availability zones. Using availability zones makes the cache more resilient to outages in a data center. For more information, see [Zone redundancy](cache-high-availability.md#zone-redundancy).
-
-    > [!IMPORTANT]
-    > Automatic Zone Allocation cannot be modified once enabled for a cache.
-
-    > [!IMPORTANT]
-    > Enabling Automatic Zone Allocation (preview) is currently NOT supported for Geo-replicated caches or caches with VNET injection.
-
-1. Availability zones can be selected manually for Premium tier caches. The number of availability zones must always be less than or equal to the total number of nodes for the cache. 
-
-   :::image type="content" source="media/cache-how-to-zone-redundancy/cache-premium-replica-count.png" alt-text="Screenshot showing Availability zones set to one and Replica count set to three.":::
-
 1. Configure your settings for clustering and/or RDB persistence.  
 
    > [!NOTE]
    > Zone redundancy doesn't support Append-only File (AOF) persistence with multiple replicas (more than one replica).
-   > Zone redundancy doesn't work with geo-replication currently.
-   >
 
 1. Select **Create**.
 
     It takes a while for the cache to be created. You can monitor progress on the Azure Cache for Redis **Overview** page. When **Status** shows as **Running**, the cache is ready to use.
 
+## Automatic Zonal Allocation
+
+Azure Cache for Redis automatically allocates zones to the cache on behalf of the user based on the number of nodes per shard and region's zonal support such that the cache is spread across multiple zones for high availability.
+
+With this type of allocation, users don't need to worry about choosing the zones manually for the cache and the capacity issues associated with the zones as Azure handles them.
+
+The actual zones that are allocated to the cache are abstracted from the user.
+
+The REST API spec for different types of zonal allocation can be found at: [Create - ZonalAllocationPolicy](/rest/api/redis/redis/create#zonalallocationpolicy).
+
+If the property `ZonalAllocationPolicy` is not passed in the request, Azure assigns its value for caches based on the region's zonal supportability and capacity.
+
+The supported values for the property `ZonalAllocationPolicy` are:
+
+1. **Automatic**
+
+This value can be passed to let Azure allocate zones automatically to the cache.
+
+In the regions that support zones, it is selected as default option for caches starting with _2024-11-01_ API version if `ZonalAllocationPolicy` isn't passed in the request.
+
+1. **UserDefined**
+
+Users are allowed to pass this value only for Premium caches and can be passed in the request body while manually selecting the zones.
+
+1. **NoZones**
+
+Users are allowed to pass this value only for Premium caches. This is the only value supported in the regions that don't support zones.
+
+- This value can't be passed by user in the request for Standard caches, since they can't explicitly choose for non zonal standard caches.
+
+It is selected as default option for caches if `ZonalAllocationPolicy` isn't passed in the request in cases:
+
+- Regions that don't support zones (irrespective of API version used).
+- All Regions (irrespective of zonal support) if API version used is less than _2024-11-01_.
+
+> [!IMPORTANT]
+> Automatic Zonal Allocation can't be modified once enabled for a cache.
+
+> [!IMPORTANT]
+>
+> - Starting with 2024-11-01 API version, Automatic Zonal Allocation is chosen as default option for Premium, Standard caches. In rare cases, when sufficient zonal capacity is unavailable to at-least allocate two zones, and user does not pass `ZonalAllocationPolicy` in the request, Azure will create a non-zonal cache which user can verify by checking the `ZonalAllocationPolicy` property in the response.
+>   - Hence, it is recommended not to pass `ZonalAllocationPolicy` in the request body while creating the cache as it will enable Azure to choose the best option among **Automatic**, **NoZones** for the cache based on the region's zonal supportability and capacity. Otherwise, users can pass `ZonalAllocationPolicy` if they want to explicitly use a specific zonal allocation policy.
+
+> [!IMPORTANT]
+  > Users can update their existing non-zonal or cache with manually selected zones to use Automatic Zonal Allocation by updating the cache with `ZonalAllocationPolicy` set to **Automatic**. For more information regarding the update process, see [Migrate an Azure Cache for Redis instance to availability zone support](#can-i-update-my-existing-standard-or-premium-cache-to-use-zone-redundancy).
+
 ## Zone Redundancy FAQ
 
 - [Why can't I enable zone redundancy when creating a Premium cache?](#why-cant-i-enable-zone-redundancy-when-creating-a-premium-cache)
 - [Why can't I select all three zones during cache create?](#why-cant-i-select-all-three-zones-during-cache-create)
-- Can I update my existing Standard or Premium cache to use zone redundancy?]
+- [Can I update my existing Standard or Premium cache to use zone redundancy?](#can-i-update-my-existing-standard-or-premium-cache-to-use-zone-redundancy)
 - [How much does it cost to replicate my data across Azure Availability Zones?](#how-much-does-it-cost-to-replicate-my-data-across-azure-availability-zones)
 
 ### Why can't I enable zone redundancy when creating a Premium cache?
@@ -90,13 +132,16 @@ A Premium cache has one primary and one replica node by default. To configure zo
 
 ### Can I update my existing Standard or Premium cache to use zone redundancy?
 
-Yes, updating an existing Standard or Premium cache to use zone redundancy is supported. You can enable it by selecting **Allocate Zones automatically** from the **Advanced settings** on the Resource menu. You can't disable zone redundancy once you enable it.
+- Yes, updating an existing Standard or Premium cache to use zone redundancy is supported in-place (Preview). Users can enable it by navigating to the **Advanced settings** on the Resource menu and selecting **Allocate Zones automatically** check-box followed by the save button. You can't disable zone redundancy once you enable it.
+- For more details, look into [Migrate an Azure Cache for Redis instance to availability zone support](/azure/reliability/migrate-cache-redis)
+- This can also be done by passing `ZonalAllocationPolicy` as `Automatic`in the request body while updating the cache. For more information regarding the update process using REST API, see [Update - ZonalAllocationPolicy](/rest/api/redis/redis/update#zonalallocationpolicy).
+  - Updating `ZonalAllocationPolicy` to any other value than `Automatic`isn't supported.
 
   > [!IMPORTANT]
-  > Automatic Zone Allocation cannot be modified once enabled for a cache.
+  > Automatic Zonal Allocation can't be modified once enabled for a cache.
 
   > [!IMPORTANT]
-  > Enabling Automatic Zone Allocation is currently NOT supported for Geo Replicated caches or caches with VNet injection.
+  > Enabling Automatic Zonal Allocation for an existing cache (which is created with a different zonal allocation) is currently NOT supported for Geo Replicated caches or caches with VNet injection.
 
 ### How much does it cost to replicate my data across Azure Availability Zones?