Redis for C#

ServiceStack.Redis

初识Redis时接触到的.Net-Redis组件是 ServiceStack.Redis，其V3系列的最新版本是：ServiceStack.Redis.3.9.29.0。

ServiceStack.Common.dll
ServiceStack.Interfaces.dll
ServiceStack.Redis.dll
ServiceStack.Text.dll

RedisClient

public void Init();
public bool ContainsKey(string key);
public bool Remove(string key);
public void RemoveByPattern(string pattern);
public void RemoveByRegex(string pattern);
public IEnumerable<string> GetKeysByPattern(string pattern);
public List<string> SearchKeys(string pattern);
public List<string> GetAllKeys();  // 数据库内的所有键（慎用）
public string GetRandomKey();
public T Get<T>(string key);
public IRedisTypedClient<T> As<T>();  //  /* 重要 */
public bool Add<T>(string key, T value [, DateTime expiresAt]); // [设置过期时间]
public bool Add<T>(string key, T value [, TimeSpan expiresIn]);
public bool Set<T>(string key, T value [, DateTime expiresAt]);  // [设置过期时间]
public bool Set<T>(string key, T value [, TimeSpan expiresIn]);
public bool ExpireEntryAt(string key, DateTime expireAt);   // 设置过期时间
public bool ExpireEntryIn(string key, TimeSpan expireIn);
public TimeSpan GetTimeToLive(string key);  // TTL时间
public long DecrementValue(string key);  // 减
public long DecrementValueBy(string key, int count);
public long IncrementValue(string key);  // 增
public long IncrementValueBy(string key, int count);

支持类型

// string
public long GetStringCount(string key);
public string GetValue(string key);
public void SetValue(string key, string value [, TimeSpan expireIn]);
public void RenameKey(string fromName, string toName);
public int AppendToValue(string key, string value);
public string GetAndSetValue(string key, string value);
public string GetSubstring(string key, int fromIndex, int toIndex);
public List<string> GetValues(List<string> keys);
public Dictionary<string, string> GetValuesMap(List<string> keys);

// List
public int GetListCount(string listId);
public int RemoveItemFromList(string listId, string value);
public string RemoveStart/End/AllFromList(string listId);
public void SetItemInList(string listId, int listIndex, string value);
public void AddItemToList(string listId, string value);
public void AddRangeToList(string listId, List<string> values);
public List<string> GetAllItemsFromList(string listId);
public string GetItemFromList(string listId, int listIndex);
public List<string> GetRangeFromList(string listId, int startingFrom, int endingAt);
public List<string> GetRangeFromSortedList(string listId, int startingFrom, int endingAt);
public List<string> GetSortedItemsFromList(string listId, SortOptions sortOptions);
public List<T> GetValues<T>(List<string> keys);
public Dictionary<string, T> GetValuesMap<T>(List<string> keys);
// List作为队列
public void EnqueueItemOnList(string listId, string value);
public string DequeueItemFromList(string listId);
// List作为栈
public void PushItemToList(string listId, string value);
public string PopItemFromList(string listId);
public string PopAndPushItemBetweenLists(string fromListId, string toListId);

// Set
public int GetSetCount(string setId);
public bool SetContainsItem(string setId, string item);
public void RemoveItemFromSet(string setId, string item);
public void AddItemToSet(string setId, string item);
public void AddRangeToSet(string setId, List<string> items);
public HashSet<string> GetAllItemsFromSet(string setId);
public string GetRandomItemFromSet(string setId);
public List<string> GetSortedEntryValues(string setId, int startingFrom, int endingAt);
public HashSet<string> GetDifferencesFromSet(string fromSetId, params string[] withSetIds);
public HashSet<string> GetIntersectFromSets(params string[] setIds);
public HashSet<string> GetUnionFromSets(params string[] setIds);
public void StoreDifferencesFromSet(string intoSetId, string fromSetId, params string[] withSetIds);
public void StoreIntersectFromSets(string intoSetId, params string[] setIds);
public void StoreUnionFromSets(string intoSetId, params string[] setIds);
public void MoveBetweenSets(string fromSetId, string toSetId, string item);
public string PopItemFromSet(string setId);　

// Hash
public int GetHashCount(string hashId);
public bool HashContainsEntry(string hashId, string key);
public bool RemoveEntryFromHash(string hashId, string key);
public bool SetEntryInHash(string hashId, string key, string value);
public List<string> GetHashKeys(string hashId);
public List<string> GetHashValues(string hashId);
public Dictionary<string, string> GetAllEntriesFromHash(string hashId);
public string GetValueFromHash(string hashId, string key);
public List<string> GetValuesFromHash(string hashId, params string[] keys);
public T GetFromHash<T>(object id);

// SortedSet（zset）
public int GetSortedSetCount(string setId);
public bool SortedSetContainsItem(string setId, string value);
public bool RemoveItemFromSortedSet(string setId, string value);
public bool AddItemToSortedSet(string setId, string value [, double score]);
public bool AddRangeToSortedSet(string setId, List<string> values [, double score]);
public List<string> GetRangeFromSortedSet(string setId, int fromRank, int toRank);
public IDictionary<string, double> GetRangeWithScoresFromSortedSet(string setId, int fromRank, int toRank);
public List<string> GetAllItemsFromSortedSet[Desc](string setId);
public IDictionary<string, double> GetAllWithScoresFromSortedSet(string setId);

其中， public IRedisTypedClient<T> As<T>();  搭配接口 public interface IRedisTypedClient<T> : IEntityStore<T>{} 和 public interface IEntityStore<T>{}  中提供的方法可以完成各种操作。

在V3.0版本的基础上，其V4.0版本 ServiceStack.Redis-4.0.52 提供了更多的方法：

• Scan方法；
• 获取设置配置信息；
• 支持Lua脚本；　

public RedisText Custom(params object[] cmdWithArgs);  // 执行命令
public RedisClient CloneClient();
public string GetClient();
public void SetClient(string name);
public void KillClient(string address);
public void ChangeDb(long db);
public DateTime GetServerTime();
public DateTime ConvertToServerDate(DateTime expiresAt);
public List<Dictionary<string, string>> GetClientsInfo();
public string GetConfig(string configItem);
public void SetConfig(string configItem, string value);
public void SaveConfig();
public void ResetInfoStats();

其中，Custom()方法可以执行绝大多数的Redis命令，ServiceStack.Redis.Commands定义命令，用于Custom()方法的第一个参数：

public static class Commands{
        public static readonly byte[] CommandName;
}

• .NET中使用Redis - 一个Blog的Demo；
• ServiceStack.Redis初步实践 - 简单Blog实现；

由于ServiceStack.Redis的V4.0版本沦为商业用途，需充值否则限制：1）数据类型； 2）每小时访问次数6000

关于破解V4.0版本限制，参见：https://blog.csdn.net/hwt0101/article/details/80545383

虽然ServiceStack.Redis有15%的性能优势，但还是推荐使用：StackExchange.Redis　

StackExchange.Redis

StackExchange.Redis是专为.Net的Redis客户端API，被StackOverFlow、微软官方RedisSessionStateProvider也采用StackExchange.Redis实现。Cache组件 | 微软官方；

RedisHelper.dll
StackExchange.Redis.dll

核心：ConnectionMultiplexer类（线程安全），在命名空间StackExchange.Redis中定义，封装Redis服务的操作细节，该类的实例被整个应用程序域共享和重用

ConnectionMultiplexer redisClient = ConnectionMultiplexer.Connect("localhost");
IDatabase db = redisClient .GetDatabase();

• StackExchange.Redis Client初步详解；
• 玩转Redis； Redis到底该如何利用（1-3）；

提供一个工具类参考

public class RedisUtils<T> where T : class
{
	private readonly ConnectionMultiplexer redisConnect;
	private readonly IDatabase db;
	private readonly JilJsonUtil<T> _jilUtil;

	public RedisUtils(string connectionString)
	{
		_jilUtil = new JilJsonUtil<T>();
		redisConnect = ConnectionMultiplexer.Connect(connectionString);
		redisConnect.PreserveAsyncOrder = false;
		db = redisConnect.GetDatabase();
	}

	public string GetString(string _key)
	{
		return db.StringGet(_key);
	}
	public Dictionary<String, T> GetBatch(HashSet<String> keys)
	{
		Dictionary<String, T> res = new Dictionary<String, T>();

		Dictionary<string, RedisValue> stringPipelineDic= GetStringPipelining(keys);
		foreach (var key in stringPipelineDic.Keys)
		{
			var value = stringPipelineDic[key];
			if (!value.IsNullOrEmpty)
			{
				res.Add(key, _jilUtil.Deserialize(value));
			}
		}

		return res;
	}       

	///批量查询
	private Dictionary<string, RedisValue> GetStringPipelining(HashSet<String> keys)
	{
		Dictionary<string, RedisValue> res = new Dictionary<string, RedisValue>();

		Dictionary<string, Task<RedisValue>> tmp = new Dictionary<string, Task<RedisValue>>();
		IBatch batch = db.CreateBatch();
		foreach (var it in keys)
		{
			Task<RedisValue> stringGetAsync = batch.StringGetAsync(it);
			tmp.Add(it, stringGetAsync);
		}
		batch.Execute();

		foreach (var it in keys)
		{
			Task<RedisValue> stringGetAsync = tmp[it];
			if (!stringGetAsync.Result.IsNullOrEmpty)
			{
				res.Add(it, stringGetAsync.Result);
			}
		}

		return res;
	}

	///存单个string的最大值是512M
	public bool SetString(string key, string valStr, int seconds)
	{
		return db.StringSet(key, valStr, TimeSpan.FromSeconds(seconds));
	}
	public bool Set(string key, T value, int seconds)
	{
		var jsonStr = _jilUtil.Serialize(value);
		return db.StringSet(key, jsonStr, TimeSpan.FromSeconds(seconds));
	}

	///PipeLine
	public void SetBatch(Dictionary<string, T> dic, int seconds)
	{
		IBatch ibatch = db.CreateBatch();
		foreach (var _key in dic.Keys)
		{
			T val = dic[_key];
			ibatch.StringSetAsync(_key, _jilUtil.Serialize(val), TimeSpan.FromSeconds(seconds));
		}
		ibatch.Execute();
	}
}

问题解决

[1]. 连接redis集群报错：（StackExchange.Redis.dll-v1.2.1）

StackExchange.Redis.RedisConnectionException: It was not possible to connect to the redis server(s);
    to create a disconnected multiplexer, disable AbortOnConnectFail. InternalFailure on PING
 在 StackExchange.Redis.ConnectionMultiplexer.ConnectImpl(Func`1 multiplexerFactory, TextWriter log)
 在 StackExchange.Redis.ConnectionMultiplexer.Connect(String configuration, TextWriter log)

原因：客户端dll版本与redis集群不兼容，替换为 v1.2.6 即可

管道（PipeLine）/批量（Batch）

• 命令打包，降低通信往返时延

关于性能提升：参考1，参考2

StackExchange.Redis两个神器：ConnectionCounters 和 IProfiler

• ConnectionCounters：分析线程瞬时状态
• IProfiler：跟踪一个请求总共执行redis命令及执行时长

对StackExchange.Redis的封装，参见：

• https://www.cnblogs.com/liqingwen/p/6672452.html
• https://www.cnblogs.com/qtqq/p/5951201.html（推荐）

但是，V1.0版本存在 timeout的问题，超时和异步慢的问题初探解决方法：

// 解决超时
ThreadPool.SetMinThreads(xx, xx);
// 解决异步慢
connection.PreserveAsyncOrder = false;

该问题在 StackExchange.Redis 2.0 中已解决，重构了异步队列，采用管道方式解决了异步慢的问题，参见：https://www.cnblogs.com/qhca/p/9347604.html

在 StackExchange.Redis二次封装 中，建议不要用lock作为单例使用，避免出现超时问题，待验证....

应用

Log4net+redis日志队列：https://www.cnblogs.com/dissun/p/10558817.html

Redis监控：由 Opserver工具  ==> RedisMonitor

基于 Redis的 Session共享

环境配置

.NET Framework 4.5 （推荐配置）
Microsoft.Web.RedisSessionStateProvider V2.2.6
StackExchange.Redis.StrongName V1.2.1

.NET Framework 4.6.1
RedisSessionProvider V1.2.8
StackExchange.Redis V2.0.6（貌似会报错，提示用低版本V1.2.6）

使用方法　　

public static void RegistRedis()
{
    StackExchange.Redis.ConfigurationOptions redisConfigOpts =
        StackExchange.Redis.ConfigurationOptions.Parse("127.0.0.1:6379");
    redisConfigOpts.Password = "********";

    RedisSessionProvider.Config.RedisConnectionConfig.GetSERedisServerConfig =
        (context) =>
        {
            return new KeyValuePair<string, StackExchange.Redis.ConfigurationOptions>(
                "DefaultConnection", redisConfigOpts);
        };
    RedisSessionProvider.Config.RedisSessionConfig.SessionTimeout = TimeSpan.MaxValue;
}

CsRedis.Core

CsRedis 开源地址参见：https://github.com/2881099/csredis

/// .NET Framework 4.6
/// NuGet.Tools.vsix V2.12
/// CSRdeis.Core V3.0.62

CsRedis引入：https://www.cnblogs.com/kellynic/p/9803314.html