Merge pull request #261557 from bjqian/main

add how to scale for webpubsub

Author: JamesJBarnett

articles/azure-web-pubsub/howto-scale-manual-scale.md

@@ -0,0 +1,88 @@
+---
+title: Scale an instance of Azure Web PubSub Service
+description: Learn how to scale an Azure Web PubSub Service instance to add or reduce capacity, through Azure portal or Azure CLI.
+author: biqian
+ms.service: azure-web-pubsub
+ms.topic: how-to
+ms.date: 12/19/2023
+ms.author: biqian 
+ms.custom: devx-track-azurecli
+---
+# How to scale an Azure Web PubSub Service instance?
+This article shows you how to scale your instance of Azure Web PubSub Service. There are two scenarios for scaling, scale up and scale out.
+
+* [Scale up](https://en.wikipedia.org/wiki/Scalability#Horizontal_and_vertical_scaling): Get more units, connections, messages, and more. You scale up by changing the pricing tier from Free to Standard.
+* [Scale out](https://en.wikipedia.org/wiki/Scalability#Horizontal_and_vertical_scaling): Increase the number of Web PubSub units. You can scale out to as many as 100 units. There are limited unit options to select for the scaling: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 units for a single Web PubSub Service instance. If you want to scale beyond 100 units, the [Premium_P2](#enhanced-large-instance-support-with-premium_p2-sku) SKU offers expanded capabilities.
+
+The scale settings take a few minutes to apply. In rare cases, it may take around 30 minutes to apply. Scaling doesn't require you to change your code or redeploy your server application.
+
+For information about the pricing and capacities of individual Web PubSub Service, see [Azure Web PubSub Service Pricing Details](https://azure.microsoft.com/pricing/details/web-pubsub/).  
+
+> [!NOTE]
+> Changing Web PubSub Service from **Free** tier to **Standard** or **Premium** tier or vice versa, the public service IP will be changed and it usually takes 30-60 minutes to propagate the change to DNS servers across the entire internet. Chaning tiers between  **Standard** and **Premium** will not change the public IP.
+> Your service might be unreachable before DNS gets updated. Generally it’s not recommended to change your pricing tier too often.
+
+
+## Scale up on Azure portal
+
+1. In your browser, open the [Azure portal](https://portal.azure.com).
+
+2. In your Web PubSub Service page, from the left menu, select **Scale Up**.
+   
+3. Click **Change** and select **Premium_P1** Tier in the pop out blade.
+   
+    ![Screenshot of scaling up on Portal.](./media/howto-scale-manual-scale/web-pubsub-howto-scale-up.png)
+
+4. Select **Save**.
+
+
+## Scale out on Azure portal
+
+1. In your browser, open the [Azure portal](https://portal.azure.com).
+
+2. In your Web PubSub Service page, from the left menu, select **Scale Out**.
+   
+3. Choose the unit in the **Manual scale** sector.
+
+    ![Screenshot of scaling out on Portal.](./media/howto-scale-manual-scale/web-pubsub-howto-scale-out.png)
+
+4. Select **Save**.
+
+
+## Scale using Azure CLI
+
+```bash
+# Scale up to Premium_P1 Tier, and scale out to 100 units
+az webpubsub update \
+  --name $myWebPubSubName \
+  --resource-group $myResourceGroupName \
+  --sku Premium_P1 \
+  --unit-count 100
+```
+
+
+## Compare pricing tiers
+
+For detailed information, such as included messages and connections for each pricing tier, see [Web PubSub Service Pricing Details](https://azure.microsoft.com/pricing/details/web-pubsub/).
+
+For a table of service limits, quotas, and constraints in each tier, see [Web PubSub Service limits](../azure-resource-manager/management/azure-subscription-service-limits.md#azure-web-pubsub-limits).
+
+
+## Enhanced large instance support with Premium_P2 SKU
+The new Premium_P2 SKU (currently in Preview) is designed to facilitate extensive scalability for high-demand scenarios.  This SKU allows scaling among 100, 200, 300, 400, 500, 600. 700, 800, 900, 1000 units for a single Web PubSub Service instance. This enhancement enables the handling of up to **one million** concurrent connections, catering to large-scale, real-time communication needs.
+
+You can scale up the SKU to Premium_P2 using Azure portal or Azure CLI.
+
+The Premium_P2 tier uses a different architecture internally to manage a large amount of underlying resources. Thus, it's expected that scaling operations of this tier might take longer compared to those in smaller SKUs.
+
+> [!NOTE]
+> Be aware that there is a default quota limit capping the number of Web PubSub units at **150** per subscription per region. This is a soft limit and can be increased upon request. To do so, simply submit a support ticket to request an adjustment to this quota.
+
+## Next steps
+
+In this guide, you learned about how to scale single Web PubSub Service instance.
+
+Autoscale is supported in Azure Web PubSub Service Premium Tier.
+
+> [!div class="nextstepaction"]
+> [Automatically scale units of an Azure Web PubSub Service](./howto-scale-autoscale.md)