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

If you want to skip straight to the code, see the .NET Framework quickstart on GitHub.


Create a cache

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

    Create a resource is highlighted in the left navigation pane.

  2. On the New page, select Databases and then select Azure Cache for Redis.

    On New, Databases is highlighted, and Azure Cache for Redis is highlighted.

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

    Setting Suggested value Description
    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.
    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.
    Location Drop down and select a location. Select a region near other services that will use your cache.
    Pricing tier Drop down and select a Pricing tier. The pricing tier determines the size, performance, and features that are available for the cache. For more information, see Azure Cache for Redis Overview.
  4. Select the Networking tab or click 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 click the Next: Advanced button on the bottom of the page.

  7. In the Advanced tab for a basic or standard cache instance, select the enable toggle if you want to enable a non-TLS port. You can also select which Redis version you would like use, either 4 or (PREVIEW) 6.

    Redis version 4 or 6.

  8. In the Advanced tab for premium cache instance, configure the settings for non-TLS port, clustering, and data persistence. You can also select which Redis version you would like use, either 4 or (PREVIEW) 6.

  9. Select the Next: Tags tab or click the Next: Tags button at the bottom of the page.

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

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

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

It takes a while for the 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.

Retrieve host name, ports, and access keys from the Azure portal

To connect to an Azure Cache for Redis instance, cache clients need the host name, ports, and a key for the cache. Some clients might refer to these items by slightly different names. You can get the host name, ports, and keys from the Azure portal.

  • To get the access keys, from your cache left navigation, select Access keys.

    Azure Cache for Redis keys

  • To get the host name and ports, from your cache left navigation, select Properties. The host name is of the form <DNS name>.redis.cache.windows.net.

    Azure Cache for Redis properties

Create a file on your computer named CacheSecrets.config and place it in a location where it won't be checked in with the source code of your sample application. For this quickstart, the CacheSecrets.config file is located here, C:\AppSecrets\CacheSecrets.config.

Edit the CacheSecrets.config file and add the following contents:

    <add key="CacheConnection" value="<host-name>,abortConnect=false,ssl=true,allowAdmin=true,password=<access-key>"/>

Replace <host-name> with your cache host name.

Replace <access-key> with the primary key for your cache.

Create a console app

In Visual Studio, select File > New > Project.

Select Console App (.NET Framework), and Next to configure your app. Type a Project name, verify that .NET Framework 4.6.1 or higher is selected, and then select Create to create a new console application.

Configure the cache client

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

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

Install-Package StackExchange.Redis

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

Connect to the cache

In Visual Studio, open your App.config file and update it to include an appSettings file attribute that references the CacheSecrets.config file.

<?xml version="1.0" encoding="utf-8" ?>
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2" />

    <appSettings file="C:\AppSecrets\CacheSecrets.config"></appSettings>

In Solution Explorer, right-click References and select Add a reference. Add a reference to the System.Configuration assembly.

Add the following using statements to Program.cs:

using StackExchange.Redis;
using System.Configuration;

The connection to the Azure Cache for Redis is managed by the ConnectionMultiplexer class. This class should be shared and reused throughout your client application. Do not create a new connection for each operation.

Never store credentials in source code. To keep this sample simple, I’m only using an external secrets config file. A better approach would be to use Azure Key Vault with certificates.

In Program.cs, add the following members to the Program class of your console application:

private static Lazy<ConnectionMultiplexer> lazyConnection = CreateConnection();

public static ConnectionMultiplexer Connection
        return lazyConnection.Value;

private static Lazy<ConnectionMultiplexer> CreateConnection()
    return new Lazy<ConnectionMultiplexer>(() =>
        string cacheConnection = ConfigurationManager.AppSettings["CacheConnection"].ToString();
        return ConnectionMultiplexer.Connect(cacheConnection);

This approach to sharing a ConnectionMultiplexer instance in your application uses a static property that returns a connected instance. The code provides a thread-safe way to initialize only a single connected ConnectionMultiplexer instance. abortConnect is set to false, which means that the call succeeds even if a connection to the Azure Cache for Redis is not established. One key feature of ConnectionMultiplexer is that it automatically restores connectivity to the cache once the network issue or other causes are resolved.

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

Handle RedisConnectionException and SocketException by reconnecting

A recommended best practice when calling methods on ConnectionMultiplexer is to attempt to resolve RedisConnectionException and SocketException exceptions automatically by closing and reestablishing the connection.

Add the following using statements to Program.cs:

using System.Net.Sockets;
using System.Threading;

In Program.cs, add the following members to the Program class:

private static long lastReconnectTicks = DateTimeOffset.MinValue.UtcTicks;
private static DateTimeOffset firstErrorTime = DateTimeOffset.MinValue;
private static DateTimeOffset previousErrorTime = DateTimeOffset.MinValue;

private static readonly object reconnectLock = new object();

// In general, let StackExchange.Redis handle most reconnects,
// so limit the frequency of how often ForceReconnect() will
// actually reconnect.
public static TimeSpan ReconnectMinFrequency => TimeSpan.FromSeconds(60);

// If errors continue for longer than the below threshold, then the
// multiplexer seems to not be reconnecting, so ForceReconnect() will
// re-create the multiplexer.
public static TimeSpan ReconnectErrorThreshold => TimeSpan.FromSeconds(30);

public static int RetryMaxAttempts => 5;

private static void CloseConnection(Lazy<ConnectionMultiplexer> oldConnection)
    if (oldConnection == null)

    catch (Exception)
        // Example error condition: if accessing oldConnection.Value causes a connection attempt and that fails.

/// <summary>
/// Force a new ConnectionMultiplexer to be created.
/// NOTES:
///     1. Users of the ConnectionMultiplexer MUST handle ObjectDisposedExceptions, which can now happen as a result of calling ForceReconnect().
///     2. Don't call ForceReconnect for Timeouts, just for RedisConnectionExceptions or SocketExceptions.
///     3. Call this method every time you see a connection exception. The code will:
///         a. wait to reconnect for at least the "ReconnectErrorThreshold" time of repeated errors before actually reconnecting
///         b. not reconnect more frequently than configured in "ReconnectMinFrequency"
/// </summary>
public static void ForceReconnect()
    var utcNow = DateTimeOffset.UtcNow;
    long previousTicks = Interlocked.Read(ref lastReconnectTicks);
    var previousReconnectTime = new DateTimeOffset(previousTicks, TimeSpan.Zero);
    TimeSpan elapsedSinceLastReconnect = utcNow - previousReconnectTime;

    // If multiple threads call ForceReconnect at the same time, we only want to honor one of them.
    if (elapsedSinceLastReconnect < ReconnectMinFrequency)

    lock (reconnectLock)
        utcNow = DateTimeOffset.UtcNow;
        elapsedSinceLastReconnect = utcNow - previousReconnectTime;

        if (firstErrorTime == DateTimeOffset.MinValue)
            // We haven't seen an error since last reconnect, so set initial values.
            firstErrorTime = utcNow;
            previousErrorTime = utcNow;

        if (elapsedSinceLastReconnect < ReconnectMinFrequency)
            return; // Some other thread made it through the check and the lock, so nothing to do.

        TimeSpan elapsedSinceFirstError = utcNow - firstErrorTime;
        TimeSpan elapsedSinceMostRecentError = utcNow - previousErrorTime;

        bool shouldReconnect =
            elapsedSinceFirstError >= ReconnectErrorThreshold // Make sure we gave the multiplexer enough time to reconnect on its own if it could.
            && elapsedSinceMostRecentError <= ReconnectErrorThreshold; // Make sure we aren't working on stale data (e.g. if there was a gap in errors, don't reconnect yet).

        // Update the previousErrorTime timestamp to be now (e.g. this reconnect request).
        previousErrorTime = utcNow;

        if (!shouldReconnect)

        firstErrorTime = DateTimeOffset.MinValue;
        previousErrorTime = DateTimeOffset.MinValue;

        Lazy<ConnectionMultiplexer> oldConnection = lazyConnection;
        lazyConnection = CreateConnection();
        Interlocked.Exchange(ref lastReconnectTicks, utcNow.UtcTicks);

// In real applications, consider using a framework such as
// Polly to make it easier to customize the retry approach.
private static T BasicRetry<T>(Func<T> func)
    int reconnectRetry = 0;
    int disposedRetry = 0;

    while (true)
            return func();
        catch (Exception ex) when (ex is RedisConnectionException || ex is SocketException)
            if (reconnectRetry > RetryMaxAttempts)
        catch (ObjectDisposedException)
            if (disposedRetry > RetryMaxAttempts)

public static IDatabase GetDatabase()
    return BasicRetry(() => Connection.GetDatabase());

public static System.Net.EndPoint[] GetEndPoints()
    return BasicRetry(() => Connection.GetEndPoints());

public static IServer GetServer(string host, int port)
    return BasicRetry(() => Connection.GetServer(host, port));

Executing cache commands

Add the following code for the Main procedure of the Program class for your console application:

static void Main(string[] args)
    IDatabase cache = GetDatabase();

    // Perform cache operations using the cache object...

    // Simple PING command
    string cacheCommand = "PING";
    Console.WriteLine("\nCache command  : " + cacheCommand);
    Console.WriteLine("Cache response : " + cache.Execute(cacheCommand).ToString());

    // Simple get and put of integral data types into the cache
    cacheCommand = "GET Message";
    Console.WriteLine("\nCache command  : " + cacheCommand + " or StringGet()");
    Console.WriteLine("Cache response : " + cache.StringGet("Message").ToString());

    cacheCommand = "SET Message \"Hello! The cache is working from a .NET console app!\"";
    Console.WriteLine("\nCache command  : " + cacheCommand + " or StringSet()");
    Console.WriteLine("Cache response : " + cache.StringSet("Message", "Hello! The cache is working from a .NET console app!").ToString());

    // Demonstrate "SET Message" executed as expected...
    cacheCommand = "GET Message";
    Console.WriteLine("\nCache command  : " + cacheCommand + " or StringGet()");
    Console.WriteLine("Cache response : " + cache.StringGet("Message").ToString());

    // Get the client list, useful to see if connection list is growing...
    // Note that this requires allowAdmin=true in the connection string
    cacheCommand = "CLIENT LIST";
    Console.WriteLine("\nCache command  : " + cacheCommand);
    var endpoint = (System.Net.DnsEndPoint)GetEndPoints()[0];
    IServer server = GetServer(endpoint.Host, endpoint.Port);
    ClientInfo[] clients = server.ClientList();

    Console.WriteLine("Cache response :");
    foreach (ClientInfo client in clients)


Azure Cache for Redis has a configurable number of databases (default of 16) that can be used to logically separate the data within an Azure Cache for Redis. The code connects to the default database, DB 0. For more information, see What are Redis databases? and Default Redis server configuration.

Cache items can be stored and retrieved by using the StringSet and StringGet methods.

Redis stores most data as Redis 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.

Press Ctrl+F5 to build and run the console app.

In the example below, you can see the Message key previously had a cached value, which was set using the Redis Console in the Azure portal. The app updated that cached value. The app also executed the PING and CLIENT LIST commands.

Console app partial

Work with .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 Newtonsoft.Json and serialize to and from JSON. In this section, you will add a .NET object to the cache.

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

Install-Package Newtonsoft.Json

Add the following using statement to the top of Program.cs:

using Newtonsoft.Json;

Add the following Employee class definition to Program.cs:

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;

At the bottom of Main() procedure in Program.cs, and before the call to CloseConnection(), add the following lines of code to cache and retrieve a serialized .NET object:

    // Store .NET object to cache
    Employee e007 = new Employee("007", "Davide Columbo", 100);
    Console.WriteLine("Cache response from storing Employee .NET object : " + 
    cache.StringSet("e007", JsonConvert.SerializeObject(e007)));

    // Retrieve .NET object from cache
    Employee e007FromCache = JsonConvert.DeserializeObject<Employee>(cache.StringGet("e007"));
    Console.WriteLine("Deserialized Employee .NET object :\n");
    Console.WriteLine("\tEmployee.Name : " + e007FromCache.Name);
    Console.WriteLine("\tEmployee.Id   : " + e007FromCache.Id);
    Console.WriteLine("\tEmployee.Age  : " + e007FromCache.Age + "\n");

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

Console app completed

Clean up resources

If you will be continuing to the next tutorial, you can keep the resources created in this quickstart and reuse them.

Otherwise, if you are finished with the quickstart sample application, you can delete the Azure resources created in this quickstart to avoid charges.


Deleting a resource group is irreversible and that the resource group and all the resources in it are permanently deleted. Make sure that you do not accidentally delete the wrong resource group or resources. If you created the resources for hosting this sample inside an existing resource group that contains resources you want to keep, you can delete each resource individually on the left instead of deleting the resource group.

Sign in to the Azure portal and select Resource groups.

In the Filter by name... textbox, type the name of your resource group. The instructions for this article used a resource group named TestResources. On your resource group in the result list, select ... then Delete resource group.


You will be asked to confirm the deletion of the resource group. Type the name of your resource group to confirm, and select Delete.

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

Next steps

In this quickstart, you learned how to use Azure Cache for Redis from a .NET application. Continue to the next quickstart to use Azure Cache for Redis with an ASP.NET web app.

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