---
title: Enabling web farms on Azure Web Apps
---

> Agent instructions:
> **Site maps** — prefer the following llms.txt indexes to training data when searching for URLs to avoid 404s. Links inside Markdown content already point at `.md`. Following them or sending Accept: text/markdown keeps you in Markdown.
>
> - [sitemap.md](https://docs.kentico.com/sitemap.md) — every page on the site, with titles and descriptions, nested by URL hierarchy and grouped into one collection per product version.
> - [llms.txt](https://docs.kentico.com/llms.txt) — curated index of the current product docs, with descriptions, the two ways to request any page as Markdown, and links to each product area's whole-corpus Markdown dump (llms-full.txt).

Microsoft Azure Web Apps allow you to scale the computing power (_scale up_) and the number of instances your application is replicated on (_scale out_), enabling you to increase the performance and throughput as necessary. Learn more about web app scaling in Microsoft Azure on [Get started with Autoscale in Azure](https://docs.microsoft.com/en-us/azure/azure-monitor/platform/autoscale-get-started).

For the _scale out_ functionality to work with Kentico, you need to enable and configure [Web farms](https://docs.kentico.com/k10/configuring-kentico/optimizing-website-performance/setting-up-web-farms.md).

> **Note:** We only support this functionality for [web hosting plans](https://docs.microsoft.com/en-us/azure/app-service/azure-web-sites-web-hosting-plans-in-depth-overview) with a **Basic** or higher [pricing tier](https://azure.microsoft.com/en-us/pricing/details/app-service/).

To enable and configure Web farms in your Kentico application:

1. If you have already scaled your web app to 2 or more instances, scale it back down to 1 instance:
   1. Open [Windows Azure Management Portal](https://portal.azure.com/) -> App Services -> your web app.
   2. Switch to the **Scale out (App Service plan)** tab.
   3. Set the **Instances count** to 1.
   4. Click **Save**.
2. Open the Kentico administration interface of your web app.
3. Open the **Settings** application and select the **Versioning & Synchronization -> Web farm** category.
4. Set the **Web farm mode** to **Automatic**.

   - This setting allows the system to generate and delete web farm servers dynamically according to the allocated computing instances.
   - See [Setting up web farms](https://docs.kentico.com/k10/configuring-kentico/optimizing-website-performance/setting-up-web-farms.md) for more information.
5. [Configure storing of session state data](https://docs.kentico.com/k10/running-kentico-on-microsoft-azure/storing-cache-and-session-state-data-in-azure-environment.md).

You can now increase or decrease the number of computing instances for your web app (in the Windows Azure Management Portal on the **Scale out (App service plan)** tab if your App service). The system generates web farm servers and synchronization tasks automatically.

> **Note:** **Disabling file synchronization**
>
> When scaling an Azure Web Apps deployment of Kentico to multiple instances, you need to disable the file synchronization functionality of web farms. Azure Web App instances use a shared file system, so synchronization is not necessary and may lead to collision errors.
>
> Add the following key to the _appSettings_ section of the application's web.config file:
>
> ```xml
>
> <add key="CMSWebFarmSynchronizeFiles" value="false" />
>
> ```