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The Pub/Sub engine powering Redis ServerEvents and Redis MQ has been extracted and encapsulated it into a re-usable class that can be used independently for handling messages published to specific Redis Pub/Sub channels.

RedisPubSubServer processes messages in a managed background thread that automatically reconnects when the redis-server connection fails and works like an independent background Service that can be stopped and started on command.

The public API is captured in the IRedisPubSubServer interface:

public interface IRedisPubSubServer : IDisposable
{
    IRedisClientsManager ClientsManager { get; }
    // What Channels it's subscribed to
    string[] Channels { get; }

    // Run once on initial StartUp
    Action OnInit { get; set; }
    // Called each time a new Connection is Started
    Action OnStart { get; set; }
    // Invoked when Connection is broken or Stopped
    Action OnStop { get; set; }
    // Invoked after Dispose()
    Action OnDispose { get; set; }

    // Fired when each message is received
    Action<string, string> OnMessage { get; set; }
    // Fired after successfully subscribing to the specified channels
    Action<string> OnUnSubscribe { get; set; }
    // Called when an exception occurs 
    Action<Exception> OnError { get; set; }
    // Called before attempting to Failover to a new redis master
    Action<IRedisPubSubServer> OnFailover { get; set; }

    int? KeepAliveRetryAfterMs { get; set; }
    // The Current Time for RedisServer
    DateTime CurrentServerTime { get; }

    // Current Status: Starting, Started, Stopping, Stopped, Disposed
    string GetStatus();
    // Different life-cycle stats
    string GetStatsDescription();
    
    // Subscribe to specified Channels and listening for new messages
    IRedisPubSubServer Start();
    // Close active Connection and stop running background thread
    void Stop();
    // Stop than Start
    void Restart();
}

To use RedisPubSubServer, initialize it with the channels you want to subscribe to and assign handlers for each of the events you want to handle. At a minimum you'll want to handle OnMessage:

var clientsManager = new PooledRedisClientManager();
var redisPubSub = new RedisPubSubServer(clientsManager, "channel-1", "channel-2") {
        OnMessage = (channel, msg) => "Received '{0}' from '{1}'".Print(msg, channel)
    }.Start();

Calling Start() after it's initialized will get it to start listening and processing any messages published to the subscribed channels.

The new ZRANGEBYLEX sorted set operations allowing you to query a sorted set lexically have been added. A good showcase for this is available on autocomplete.redis.io.

These new operations are available as a 1:1 mapping with redis-server on IRedisNativeClient:

public interface IRedisNativeClient
{
    ...
    byte[][] ZRangeByLex(string setId, string min, string max, int? skip=null, int? take=null);
    long ZLexCount(string setId, string min, string max);
    long ZRemRangeByLex(string setId, string min, string max);
}

And the more user-friendly APIs under IRedisClient:

public interface IRedisClient
{
    ...
    List<string> SearchSortedSet(string setId, string start=null, string end=null);
    long SearchSortedSetCount(string setId, string start=null, string end=null);
    long RemoveRangeFromSortedSetBySearch(string setId, string start=null, string end=null);
}

Just like NuGet version matchers, Redis uses [ char to express inclusiveness and ( char for exclusiveness. Since the IRedisClient APIs defaults to inclusive searches, these two APIs are the same:

Redis.SearchSortedSetCount("zset", "a", "c")
Redis.SearchSortedSetCount("zset", "[a", "[c")

Alternatively you can specify one or both bounds to be exclusive by using the ( prefix, e.g:

Redis.SearchSortedSetCount("zset", "a", "(c")
Redis.SearchSortedSetCount("zset", "(a", "(c")

More API examples are available in LexTests.cs.

The development branch of Redis server (available when v3.0 is released) includes an ingenious algorithm to approximate the unique elements in a set with maximum space and time efficiency. For details about how it works see Redis's creator Salvatore's blog who explains it in great detail. Essentially it lets you maintain an efficient way to count and merge unique elements in a set without having to store its elements. A Simple example of it in action:

redis.AddToHyperLog("set1", "a", "b", "c");
redis.AddToHyperLog("set1", "c", "d");
var count = redis.CountHyperLog("set1"); //4

redis.AddToHyperLog("set2", "c", "d", "e", "f");

redis.MergeHyperLogs("mergedset", "set1", "set2");

var mergeCount = redis.CountHyperLog("mergedset"); //6

Redis v2.8 introduced a beautiful new SCAN operation that provides an optimal strategy for traversing a redis instance entire keyset in managable-size chunks utilizing only a client-side cursor and without introducing any server state. It's a higher performance alternative and should be used instead of KEYS in application code. SCAN and its related operations for traversing members of Sets, Sorted Sets and Hashes are now available in the Redis Client in the following API's:

public interface IRedisClient
{
    ...
    IEnumerable<string> ScanAllKeys(string pattern = null, int pageSize = 1000);
    IEnumerable<string> ScanAllSetItems(string setId, string pattern = null, int pageSize = 1000);
    IEnumerable<KeyValuePair<string, double>> ScanAllSortedSetItems(string setId, string pattern = null, int pageSize = 1000);
    IEnumerable<KeyValuePair<string, string>> ScanAllHashEntries(string hashId, string pattern = null, int pageSize = 1000);    
}

//Low-level API
public interface IRedisNativeClient
{
    ...
    ScanResult Scan(ulong cursor, int count = 10, string match = null);
    ScanResult SScan(string setId, ulong cursor, int count = 10, string match = null);
    ScanResult ZScan(string setId, ulong cursor, int count = 10, string match = null);
    ScanResult HScan(string hashId, ulong cursor, int count = 10, string match = null);
}

The IRedisClient provides a higher-level API that abstracts away the client cursor to expose a lazy Enumerable sequence to provide an optimal way to stream scanned results that integrates nicely with LINQ, e.g:

var scanUsers = Redis.ScanAllKeys("urn:User:*");
var sampleUsers = scanUsers.Take(10000).ToList(); //Stop after retrieving 10000 user keys 

The IRedisClient API's for redis server-side LUA support have been re-factored into the more user-friendly API's below:

public interface IRedisClient 
{
    //Eval/Lua operations 

    string ExecLuaAsString(string luaBody, params string[] args);
    string ExecLuaAsString(string luaBody, string[] keys, string[] args);
    string ExecLuaShaAsString(string sha1, params string[] args);
    string ExecLuaShaAsString(string sha1, string[] keys, string[] args);
    
    int ExecLuaAsInt(string luaBody, params string[] args);
    int ExecLuaAsInt(string luaBody, string[] keys, string[] args);
    int ExecLuaShaAsInt(string sha1, params string[] args);
    int ExecLuaShaAsInt(string sha1, string[] keys, string[] args);

    List<string> ExecLuaAsList(string luaBody, params string[] args);
    List<string> ExecLuaAsList(string luaBody, string[] keys, string[] args);
    List<string> ExecLuaShaAsList(string sha1, params string[] args);
    List<string> ExecLuaShaAsList(string sha1, string[] keys, string[] args);

    string CalculateSha1(string luaBody);
    
    bool HasLuaScript(string sha1Ref);
    Dictionary<string, bool> WhichLuaScriptsExists(params string[] sha1Refs);
    void RemoveAllLuaScripts();
    void KillRunningLuaScript();
    string LoadLuaScript(string body);
}

Here's how you can implement a ZPOP in Lua to remove the items with the lowest rank from a sorted set:

var luaBody = @"
    local val = redis.call('zrange', KEYS[1], 0, ARGV[1]-1)
    if val then redis.call('zremrangebyrank', KEYS[1], 0, ARGV[1]-1) end
    return val";

var i = 0;
var alphabet = 26.Times(c => ((char)('A' + c)).ToString());
alphabet.ForEach(x => Redis.AddItemToSortedSet("zalphabet", x, i++));

//Remove the letters with the lowest rank from the sorted set 'zalphabet'
var letters = Redis.ExecLuaAsList(luaBody, keys: new[] { "zalphabet" }, args: new[] { "3" });
letters.PrintDump(); //[A, B, C]

And how to implement ZREVPOP to remove items with the highest rank from a sorted set:

var luaBody = @"
    local val = redis.call('zrange', KEYS[1], -ARGV[1], -1)
    if val then redis.call('zremrangebyrank', KEYS[1], -ARGV[1], -1) end
    return val";

var i = 0;
var alphabet = 26.Times(c => ((char)('A' + c)).ToString());
alphabet.ForEach(x => Redis.AddItemToSortedSet("zalphabet", x, i++));

//Remove the letters with the highest rank from the sorted set 'zalphabet'
List<string> letters = Redis.ExecLuaAsList(luaBody, keys: new[] { "zalphabet" }, args: new[] { "3" });

letters.PrintDump(); //[X, Y, Z]

Returning an int:

int intVal = Redis.ExecLuaAsInt("return 123"); //123
int intVal = Redis.ExecLuaAsInt("return ARGV[1] + ARGV[2]", "10", "20"); //30

Returning an string:

var strVal = Redis.ExecLuaAsString(@"return 'Hello, ' .. ARGV[1] .. '!'", "Redis Lua"); //Hello, Redis Lua!

Returning a List of strings:

Enum.GetNames(typeof(DayOfWeek)).ToList()
    .ForEach(x => Redis.AddItemToList("DaysOfWeek", x));

var daysOfWeek = Redis.ExecLuaAsList("return redis.call('LRANGE', 'DaysOfWeek', 0, -1)");
daysOfWeek.PrintDump(); //[Sunday, Monday, Tuesday, ...]

More examples can be found in the Redis Eval Lua tests

The Redis client is an independent project and can be used with or without the ServiceStack webservices framework.

Redis is one of the fastest and most feature-rich key-value stores to come from the NoSQL movement. It is similar to memcached but the dataset is not volatile, and values can either be strings lists, sets, sorted sets or hashes.

ServiceStack's C# Redis Client is an Open Source C# Redis client based on Miguel de Icaza previous efforts with redis-sharp.

There are a number of different APIs available which are all a friendly drop-in with your local IOC: The ServiceStack.Redis.RedisClient class below implements the following interfaces:

• ICacheClient - If you are using Redis solely as a cache, you should bind to the ServiceStack's common interface as there already are In-Memory an Memcached implementations available in ServiceStack, allowing you to easily switch providers in-future.
• IRedisNativeClient - For those wanting a low-level raw byte access (where you can control your own serialization/deserialization) that map 1:1 with Redis operations of the same name.

For most cases if you require access to Redis-specific functionality you would want to bind to the interface below:

• IRedisClient - Provides a friendlier, more descriptive API that lets you store values as strings (UTF8 encoding).
• IRedisTypedClient - created with IRedisClient.As<T>() - it returns a 'strongly-typed client' that provides a typed-interface for all redis value operations that works against any C#/.NET POCO type.

The class hierachy for the C# Redis clients effectively look like:

RedisTypedClient (POCO) > RedisClient (string) > RedisNativeClient (raw byte[])

Each client provides a different layer of abstraction:

• The RedisNativeClient exposes raw byte[] apis and does no marshalling and passes all values directly to redis.
• The RedisClient assumes string values and simply converts strings to UTF8 bytes before sending to Redis
• The RedisTypedClient provides a generic interface allowing you to add POCO values. The POCO types are serialized using .NETs fastest JSON Serializer which is then converted to UTF8 bytes and sent to Redis.

For multi-threaded applications you can choose from our different client connection managers:

• BasicRedisClientManager - a load-balance (master-write and read-slaves) client manager that returns a new IRedisClient connection with the defaults specified (faster when accessing a redis-server instance on the same host).
• PooledRedisClientManager - a load-balanced (master-write and read-slaves) client manager that utilizes a pool of redis client connections (faster when accessing a redis-server instance over the network).

PM> Install-Package ServiceStack.Redis

Latest v4+ on NuGet is a commercial release with free quotas.

Since September 2013, ServiceStack source code is available under GNU Affero General Public License/FOSS License Exception, see license.txt in the source. Alternative commercial licensing is also available, see https://servicestack.net/pricing for details.

Commits should be made to the v3-fixes branch so they can be merged into both v3 and master (v4) release branches. Contributors need to approve the Contributor License Agreement before any code will be reviewed, see the Contributing wiki for more details.

• MS Open Tech - Redis on Windows
• Downloads for Cygwin 32bit Redis Server Windows builds.
• Project that lets you run Redis as a Windows Service
• Another Redis as a Windows Service project, which allows you to run separate service for each Redis instance
• Downloads for MinGW 32bit and 64bit Redis Server Windows builds

• Run Redis in a Vagrant virtual machine

###C# Redis Client wiki Contains all the examples, tutorials and resources you need to get you up to speed with common operations and the latest features.

Useful Links on Redis server

• Using Transactions in Redis (i.e. MULTI/EXEC/DISCARD)
• Using Redis's built-in Publish/Subscribe pattern for high performance network notifications
• Using Redis to create high performance distributed locks spannable across multiple app servers

Below is a simple example to give you a flavour of how easy it is to use some of Redis's advanced data structures - in this case Redis Lists: Full source code of this example is viewable online

using (var redisClient = new RedisClient())
{
    //Create a 'strongly-typed' API that makes all Redis Value operations to apply against Shippers
    IRedisTypedClient<Shipper> redis = redisClient.As<Shipper>();

    //Redis lists implement IList<T> while Redis sets implement ICollection<T>
    var currentShippers = redis.Lists["urn:shippers:current"];
    var prospectiveShippers = redis.Lists["urn:shippers:prospective"];

    currentShippers.Add(
        new Shipper {
            Id = redis.GetNextSequence(),
            CompanyName = "Trains R Us",
            DateCreated = DateTime.UtcNow,
            ShipperType = ShipperType.Trains,
            UniqueRef = Guid.NewGuid()
        });

    currentShippers.Add(
        new Shipper {
            Id = redis.GetNextSequence(),
            CompanyName = "Planes R Us",
            DateCreated = DateTime.UtcNow,
            ShipperType = ShipperType.Planes,
            UniqueRef = Guid.NewGuid()
        });

    var lameShipper = new Shipper {
        Id = redis.GetNextSequence(),
        CompanyName = "We do everything!",
        DateCreated = DateTime.UtcNow,
        ShipperType = ShipperType.All,
        UniqueRef = Guid.NewGuid()
    };

    currentShippers.Add(lameShipper);

    Dump("ADDED 3 SHIPPERS:", currentShippers);

    currentShippers.Remove(lameShipper);

    Dump("REMOVED 1:", currentShippers);

    prospectiveShippers.Add(
        new Shipper {
            Id = redis.GetNextSequence(),
            CompanyName = "Trucks R Us",
            DateCreated = DateTime.UtcNow,
            ShipperType = ShipperType.Automobiles,
            UniqueRef = Guid.NewGuid()
        });

    Dump("ADDED A PROSPECTIVE SHIPPER:", prospectiveShippers);

    redis.PopAndPushBetweenLists(prospectiveShippers, currentShippers);

    Dump("CURRENT SHIPPERS AFTER POP n' PUSH:", currentShippers);
    Dump("PROSPECTIVE SHIPPERS AFTER POP n' PUSH:", prospectiveShippers);

    var poppedShipper = redis.PopFromList(currentShippers);
    Dump("POPPED a SHIPPER:", poppedShipper);
    Dump("CURRENT SHIPPERS AFTER POP:", currentShippers);

    //reset sequence and delete all lists
    redis.SetSequence(0);
    redis.Remove(currentShippers, prospectiveShippers);
    Dump("DELETING CURRENT AND PROSPECTIVE SHIPPERS:", currentShippers);
}

/*
== EXAMPLE OUTPUT ==

ADDED 3 SHIPPERS:
Id:1,CompanyName:Trains R Us,ShipperType:Trains,DateCreated:2010-01-31T11:53:37.7169323Z,UniqueRef:d17c5db0415b44b2ac5da7b6ebd780f5
Id:2,CompanyName:Planes R Us,ShipperType:Planes,DateCreated:2010-01-31T11:53:37.799937Z,UniqueRef:e02a73191f4b4e7a9c44eef5b5965d06
Id:3,CompanyName:We do everything!,ShipperType:All,DateCreated:2010-01-31T11:53:37.8009371Z,UniqueRef:d0c249bbbaf84da39fc4afde1b34e332

REMOVED 1:
Id:1,CompanyName:Trains R Us,ShipperType:Trains,DateCreated:2010-01-31T11:53:37.7169323Z,UniqueRef:d17c5db0415b44b2ac5da7b6ebd780f5
Id:2,CompanyName:Planes R Us,ShipperType:Planes,DateCreated:2010-01-31T11:53:37.799937Z,UniqueRef:e02a73191f4b4e7a9c44eef5b5965d06

ADDED A PROSPECTIVE SHIPPER:
Id:4,CompanyName:Trucks R Us,ShipperType:Automobiles,DateCreated:2010-01-31T11:53:37.8539401Z,UniqueRef:67d7d4947ebc4b0ba5c4d42f5d903bec

CURRENT SHIPPERS AFTER POP n' PUSH:
Id:4,CompanyName:Trucks R Us,ShipperType:Automobiles,DateCreated:2010-01-31T11:53:37.8539401Z,UniqueRef:67d7d4947ebc4b0ba5c4d42f5d903bec
Id:1,CompanyName:Trains R Us,ShipperType:Trains,DateCreated:2010-01-31T11:53:37.7169323Z,UniqueRef:d17c5db0415b44b2ac5da7b6ebd780f5
Id:2,CompanyName:Planes R Us,ShipperType:Planes,DateCreated:2010-01-31T11:53:37.799937Z,UniqueRef:e02a73191f4b4e7a9c44eef5b5965d06

PROSPECTIVE SHIPPERS AFTER POP n' PUSH:

POPPED a SHIPPER:
Id:2,CompanyName:Planes R Us,ShipperType:Planes,DateCreated:2010-01-31T11:53:37.799937Z,UniqueRef:e02a73191f4b4e7a9c44eef5b5965d06

CURRENT SHIPPERS AFTER POP:
Id:4,CompanyName:Trucks R Us,ShipperType:Automobiles,DateCreated:2010-01-31T11:53:37.8539401Z,UniqueRef:67d7d4947ebc4b0ba5c4d42f5d903bec
Id:1,CompanyName:Trains R Us,ShipperType:Trains,DateCreated:2010-01-31T11:53:37.7169323Z,UniqueRef:d17c5db0415b44b2ac5da7b6ebd780f5

DELETING CURRENT AND PROSPECTIVE SHIPPERS:
*/

More examples are available in the [RedisExamples Redis examples page] and in the comprehensive test suite

One of the best things about Redis is the speed - it is quick.

This example below stores and gets the entire Northwind database (3202 records) in less 1.2 secs - we've never had it so quick!

(Running inside a VS.NET/R# unit test on a 3 year old iMac)

using (var client = new RedisClient())
{
    var before = DateTime.Now;
    client.StoreAll(NorthwindData.Categories);
    client.StoreAll(NorthwindData.Customers);
    client.StoreAll(NorthwindData.Employees);
    client.StoreAll(NorthwindData.Shippers);
    client.StoreAll(NorthwindData.Orders);
    client.StoreAll(NorthwindData.Products);
    client.StoreAll(NorthwindData.OrderDetails);
    client.StoreAll(NorthwindData.CustomerCustomerDemos);
    client.StoreAll(NorthwindData.Regions);
    client.StoreAll(NorthwindData.Territories);
    client.StoreAll(NorthwindData.EmployeeTerritories);

    Console.WriteLine("Took {0}ms to store the entire Northwind database ({1} records)",
        (DateTime.Now - before).TotalMilliseconds, totalRecords);


    before = DateTime.Now;
    var categories = client.GetAll<Category>();
    var customers = client.GetAll<Customer>();
    var employees = client.GetAll<Employee>();
    var shippers = client.GetAll<Shipper>();
    var orders = client.GetAll<Order>();
    var products = client.GetAll<Product>();
    var orderDetails = client.GetAll<OrderDetail>();
    var customerCustomerDemos = client.GetAll<CustomerCustomerDemo>();
    var regions = client.GetAll<Region>();
    var territories = client.GetAll<Territory>();
    var employeeTerritories = client.GetAll<EmployeeTerritory>();

    Console.WriteLine("Took {0}ms to get the entire Northwind database ({1} records)",
        (DateTime.Now - before).TotalMilliseconds, totalRecords);
}
/*
== EXAMPLE OUTPUT ==

Took 1020.0583ms to store the entire Northwind database (3202 records)
Took 132.0076ms to get the entire Northwind database (3202 records)
*/

Note: The total time taken includes an extra Redis operation for each record to store the id in a Redis set for each type as well as serializing and de-serializing each record using Service Stack's TypeSerializer.

• Distributed Caching using Redis Server with .NET/C# Client by Sem.Shekhovtsov
• Fan Messaging with ServiceStack.Redis by miket
• Redis and VB.Net by @chrissie1
• Using ServiceStack.Redis Part 2: Sets and Hashes by @msarchet
• Using the ServiceStack.Redis Client by @msarchet
• Implementing ServiceStack.Redis.RedisClient (.NET Client for Redis) by @NarizWallace
• Getting started with Redis in ASP.NET under Windows by @maxivak
• Using Redis on Windows with ServiceStack