Quickstart: Use Azure Cache for Redis in .NET Framework

In this quickstart, you incorporate Azure Cache for Redis into a .NET Framework app to have access to a secure, dedicated cache that is accessible from any application within Azure. You specifically use the StackExchange.Redis client with C# code in a .NET console app.

Skip to the code on GitHub

Clone the repo from Azure-Samples/azure-cache-redis-samples on GitHub.

Prerequisites

• An Azure subscription. Create one
• Visual Studio 2019
• .NET Framework 4 or higher, which is required by the StackExchange.Redis client.

Create a cache

1. To create a cache, sign in to the Azure portal and select Create a resource.

   

2. On the Get Started page, type Azure Cache for Redis in the search box. Then, select Create.

   

3. On the New Redis Cache page, configure the settings for your cache.

   Setting	Choose a value	Description
   Subscription	Drop down and select your subscription.	The subscription under which to create this new Azure Cache for Redis instance.
   Resource group	Drop down and 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 unique name.	The cache name must be a string between 1 and 63 characters that contain 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 is <DNS name>.redis.cache.chinacloudapi.cn.
   Location	Drop down and select a location.	Select a region near other services that use your cache.
   Cache SKU	Drop down and select a SKU.	The SKU determines the size, performance, and features parameters that are available for the cache. For more information, see Azure Cache for Redis Overview.
   Cache size	Drop down and select a size of your cache	For more information, see Azure Cache for Redis Overview.

4. Select the Networking tab or select the Networking button at the bottom of the page.

5. In the Networking tab, select your connectivity method.

6. Select the Next: Advanced tab or select the Next: Advanced button on the bottom of the page to see the Advanced tab.

   

   • For Basic or Standard caches, toggle the selection for a non-TLS port. You can also select if you want to enable Microsoft Entra Authentication.
   • For a Premium cache, configure the settings for non-TLS port, clustering, managed identity, and data persistence. You can also select if you want to enable Microsoft Entra Authentication.

7. Select the Next: Tags tab or select the Next: Tags button at the bottom of the page.

8. Optionally, in the Tags tab, enter the name and value if you wish to categorize the resource.

9. Select Review + create. You're taken to the Review + create tab where Azure validates your configuration.

10. After the green Validation passed message appears, select Create.

It takes a while for a cache to create. You can monitor progress on the Azure Cache for Redis Overview page. When Status shows as Running, the cache is ready to use.

Enable Microsoft Entra ID authentication on your cache

If you have a cache, check to see if Microsoft Entra Authentication has been enabled. If not, then enable it. We recommend using Microsoft Entra ID for your apps.

1. In the Azure portal, select the Azure Cache for Redis instance where you'd like to use Microsoft Entra token-based authentication.

2. Select Authentication from the Resource menu.

3. Check in the working pane to see if Enable Microsoft Entra Authentication is checked. If so, you can move on.

4. Select Enable Microsoft Entra Authentication, and enter the name of a valid user. The user you enter is automatically assigned Data Owner Access Policy by default when you select Save. You can also enter a managed identity or service principal to connect to your cache instance.

   

5. A popup dialog box displays asking if you want to update your configuration, and informing you that it takes several minutes. Select Yes.

   Important

   Once the enable operation is complete, the nodes in your cache instance reboots to load the new configuration. We recommend performing this operation during your maintenance window or outside your peak business hours. The operation can take up to 30 minutes.

For information on using Microsoft Entra ID with Azure CLI, see the references pages for identity.

1. Edit the App.config file and add the following contents:

   <appSettings>
   
   <add key="RedisHostName" value="your_redis_cache_hostname"/>
   

```

1. Replace "your_Azure_Redis_hostname" with your Azure Redis host name and port numbers. For example: cache-name.redis.cache.chinacloudapi.cn:6380 for Azure Cache for Redis services.

2. Save the file.

Configure the cache client

In this section, you prepare the console application to use the StackExchange.Redis client for .NET.

1. In Visual Studio, select Tools > NuGet Package Manager > Package Manager Console, and run the following command from the Package Manager Console window.

   Install-Package Microsoft.Azure.StackExchangeRedis
   

2. Once the installation is completed, the StackExchange.Redis cache client is available to use with your project.

Connect to the cache with RedisConnection

The connection to your cache is managed by the RedisConnection class. The connection is first made in this statement from Program.cs:

     _redisConnection = await RedisConnection.InitializeAsync(redisHostName: ConfigurationManager.AppSettings["RedisHostName"].ToString());

The value of the CacheConnection appSetting is used to reference the cache connection string from the Azure portal as the password parameter.

In RedisConnection.cs, you see the StackExchange.Redis namespace with the using keyword. This is needed for the RedisConnection class.

using StackExchange.Redis;

The RedisConnection code ensures that there is always a healthy connection to the cache by managing the ConnectionMultiplexer instance from StackExchange.Redis. The RedisConnection class recreates the connection when a connection is lost and unable to reconnect automatically.

For more information, see StackExchange.Redis and the code in a GitHub repo.

Executing cache commands

In program.cs, you can see the following code for the RunRedisCommandsAsync method in the Program class for the console application:

private static async Task RunRedisCommandsAsync(string prefix)
    {
        // Simple PING command
        Console.WriteLine($"{Environment.NewLine}{prefix}: Cache command: PING");
        RedisResult pingResult = await _redisConnection.BasicRetryAsync(async (db) => await db.ExecuteAsync("PING"));
        Console.WriteLine($"{prefix}: Cache response: {pingResult}");

        // Simple get and put of integral data types into the cache
        string key = "Message";
        string value = "Hello! The cache is working from a .NET console app!";

        Console.WriteLine($"{Environment.NewLine}{prefix}: Cache command: GET {key} via StringGetAsync()");
        RedisValue getMessageResult = await _redisConnection.BasicRetryAsync(async (db) => await db.StringGetAsync(key));
        Console.WriteLine($"{prefix}: Cache response: {getMessageResult}");

        Console.WriteLine($"{Environment.NewLine}{prefix}: Cache command: SET {key} \"{value}\" via StringSetAsync()");
        bool stringSetResult = await _redisConnection.BasicRetryAsync(async (db) => await db.StringSetAsync(key, value));
        Console.WriteLine($"{prefix}: Cache response: {stringSetResult}");

        Console.WriteLine($"{Environment.NewLine}{prefix}: Cache command: GET {key} via StringGetAsync()");
        getMessageResult = await _redisConnection.BasicRetryAsync(async (db) => await db.StringGetAsync(key));
        Console.WriteLine($"{prefix}: Cache response: {getMessageResult}");

        // Store serialized object to cache
        Employee e007 = new Employee("007", "Davide Columbo", 100);
        stringSetResult = await _redisConnection.BasicRetryAsync(async (db) => await db.StringSetAsync("e007", JsonSerializer.Serialize(e007)));
        Console.WriteLine($"{Environment.NewLine}{prefix}: Cache response from storing serialized Employee object: {stringSetResult}");

        // Retrieve serialized object from cache
        getMessageResult = await _redisConnection.BasicRetryAsync(async (db) => await db.StringGetAsync("e007"));
        Employee e007FromCache = JsonSerializer.Deserialize<Employee>(getMessageResult);
        Console.WriteLine($"{prefix}: Deserialized Employee .NET object:{Environment.NewLine}");
        Console.WriteLine($"{prefix}: Employee.Name : {e007FromCache.Name}");
        Console.WriteLine($"{prefix}: Employee.Id   : {e007FromCache.Id}");
        Console.WriteLine($"{prefix}: Employee.Age  : {e007FromCache.Age}{Environment.NewLine}");
    }

Cache items can be stored and retrieved by using the StringSetAsync and StringGetAsync methods.

In the example, you can see the Message key is set to value. The app updated that cached value. The app also executed the PING and command.

Work with .NET objects in the cache

The Redis server stores most data as strings, but these strings can contain many types of data, including serialized binary data, which can be used when storing .NET objects in the cache.

Azure Cache for Redis can cache both .NET objects and primitive data types, but before a .NET object can be cached it must be serialized.

This .NET object serialization is the responsibility of the application developer, and gives the developer flexibility in the choice of the serializer.

One simple way to serialize objects is to use the JsonConvert serialization methods in System.text.Json.

Add the System.text.Json namespace to Visual Studio:

1. Select Tools > NuGet Package Manager > Package Manager Console.

2. Then, run the following command from the Package Manager Console window.

   Install-Package system.text.json
   

The following Employee class was defined in Program.cs so that the sample could also show how to get and set a serialized object:

class Employee
{
    public string Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }

    public Employee(string employeeId, string name, int age)
    {
        Id = employeeId;
        Name = name;
        Age = age;
    }
}

Run the sample

Press Ctrl+F5 to build and run the console app to test serialization of .NET objects.

Clean up resources

If you want to continue to use the resources you created in this article, keep the resource group.

Otherwise, if you're finished with the resources, you can delete the Azure resource group that you created to avoid charges.

To delete a resource group

1. Sign in to the Azure portal, and then select Resource groups.

2. Select the resource group you want to delete.

   If there are many resource groups, use the Filter for any field... box, type the name of your resource group you created for this article. Select the resource group in the results list.

   

3. Select Delete resource group.

4. You're asked to confirm the deletion of the resource group. Type the name of your resource group to confirm, and then select Delete.

   

After a few moments, the resource group and all of its resources are deleted.

Next steps

• Connection resilience
• Best Practices Development