Storing cache and session state data in Azure environment

If you want your Azure Cloud Services or Azure Web App application to use two or more instances (processes dedicated to a Web App or web roles in a Cloud Service), you must configure where the application will store session state information. Session state must be stored either in the database, which is shared among the servers, or in a special service. Session state cannot be stored in the server’s memory, because the session would be lost if the web farm switched requests to another instance.

Options for storing session state information in the Azure environment:

Storing session state information in Azure SQL Database

  1. Open your Azure project in Visual Studio.
  2. Right-click the CMSApp project and select Manage NuGet packages.
  3. Install the Microsoft.AspNet.Providers package.
  4. Open the web.config file.
  5. Follow the instructions in the code comments of the sessionState section.

After this, your project is configured to store session state information in the Microsoft Azure SQL Database.

Storing session state information in Azure Redis Cache

To configure your project to use Azure Redis Cache:

  1. Create a new Redis Cache according to the instructions in the Use Azure Redis Cache with a .NET application article.

  2. Open the project in Visual Studio.

  3. Right-click the solution and select Manage NuGet Packages.

  4. Search for and install the Microsoft.Web.RedisSessionStateProvider package.

    • This action will automatically add all required assembly references to the project and create the following section in the web.config file:

      
      
      
        <sessionState mode="Custom" customProvider="MySessionStateStore">
          <providers>
            <!--
              <add name="MySessionStateStore" 
                host = "127.0.0.1" [String]
                port = "" [number]
                accessKey = "" [String]
                ssl = "false" [true|false]
                throwOnError = "true" [true|false]
                retryTimeoutInMilliseconds = "0" [number]
                databaseId = "0" [number]
                applicationName = "" [String]
                connectionTimeoutInMilliseconds = "5000" [number]
                operationTimeoutInMilliseconds = "5000" [number]
              />
            -->
            <add name="MySessionStateStore" type="Microsoft.Web.Redis.RedisSessionStateProvider" host="mycache.redis.cache.windows.net"
            accessKey="..." ssl="true" />
          </providers>
        </sessionState>
      
      
        
    • Specify the host name and accessKey values which you can find in the properties of the cache service on Azure.

      Instead of inserting the values of the host and accessKey attributes directly, you can specify them as key-value pairs in the appSettings section of the application’s web.config file. You can then reference the values anywhere in the configuration file using their assigned keys.

      
      
      
        <add key="MyRedisAccessKey" value="...">
      
      
        

      Values stored in the appSettings section can be easily accessed and managed, for example, via the Azure Portal. The contents of the section can also be encrypted, preventing untrustworthy people from accessing application secrets, such as the Redis cache provider access key.

      See the official AspNet Redis documentation for details.

  5. Comment out the default session state provider in the web.config file. 

    • By default, it is the InProc provider:

      
      
      
        <!-- <sessionState mode="InProc" customProvider="DefaultSessionProvider">
          <providers>
            <add name="DefaultSessionProvider" type="System.Web.Providers.DefaultSessionStateProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" />
          </providers>
        </sessionState> -->
      
      
        

You can now deploy your project to Azure and start utilizing Azure Redis Cache as a session state provider.