从StackExchange.Redis缓存中删除/删除所有/一项

Question

我正在使用Azure Redis缓存服务的StackExchange.Redis客户端.这是我的班级,

public class RedisCacheService : ICacheService
{
    private readonly ISettings _settings;
    private readonly IDatabase _cache;

    public RedisCacheService(ISettings settings)
    {
        _settings = settings;
        var connectionMultiplexer = ConnectionMultiplexer.Connect(settings.RedisConnection);
        _cache = connectionMultiplexer.GetDatabase();
    }

    public bool Exists(string key)
    {
        return _cache.KeyExists(key);
    }

    public void Save(string key, string value)
    {
        var ts = TimeSpan.FromMinutes(_settings.CacheTimeout);
        _cache.StringSet(key, value, ts);
    }

    public string Get(string key)
    {
        return _cache.StringGet(key);
    }

    public void Remove(string key)
    {
        // How to remove one
    }

    public void Clear()
    {
        // How to remove all
    }
}

更新:在Marc的帮助下,这是我的最后一堂课

public class RedisCacheService : ICacheService
{
    private readonly ISettings _settings;
    private readonly IDatabase _cache;
    private static ConnectionMultiplexer _connectionMultiplexer;

    static RedisCacheService()
    {
        var connection = ConfigurationManager.AppSettings["RedisConnection"];
        _connectionMultiplexer = ConnectionMultiplexer.Connect(connection);
    }

    public RedisCacheService(ISettings settings)
    {
        _settings = settings;
        _cache = _connectionMultiplexer.GetDatabase();
    }

    public bool Exists(string key)
    {
        return _cache.KeyExists(key);
    }

    public void Save(string key, string value)
    {
        var ts = TimeSpan.FromMinutes(_settings.CacheTimeout);
        _cache.StringSet(key, value, ts);
    }

    public string Get(string key)
    {
        return _cache.StringGet(key);
    }

    public void Remove(string key)
    {
        _cache.KeyDelete(key);
    }

    public void Clear()
    {
        var endpoints = _connectionMultiplexer.GetEndPoints(true);
        foreach (var endpoint in endpoints)
        {
            var server = _connectionMultiplexer.GetServer(endpoint);
            server.FlushAllDatabases();    
        }
    }
}

现在我不知道如何从redis缓存中删除所有项目或单个项目.

Answer 1

要删除单个项目:

_cache.KeyDelete(key);

要删除all,请执行FLUSHDBor FLUSHALLredis命令; 两者都可以在StackExchange.Redis中找到; 但是,由于这里讨论的原因,它们不在IDatabaseAPI上(因为:它们影响服务器,而不是逻辑数据库).

根据"那我该如何使用它们？" 在该页面上:

server.FlushDatabase(); // to wipe a single database, 0 by default
server.FlushAllDatabases(); // to wipe all databases

(很可能在使用GetEndpoints()多路复用器后)

Answer 2

我无法在Azure Redis缓存中刷新数据库,出现此错误:

除非启用管理模式,否则此操作不可用:FLUSHDB

而是遍历所有键以删除:

var endpoints = connectionMultiplexer.GetEndPoints();
var server = connectionMultiplexer.GetServer(endpoints.First());
//FlushDatabase didn't work for me: got error admin mode not enabled error
//server.FlushDatabase();
var keys = server.Keys();
foreach (var key in keys)
{
  Console.WriteLine("Removing Key {0} from cache", key.ToString());
  _cache.KeyDelete(key);
}

Answer 3

@Rasi 和 @Marc Gravell 的两个答案都包含所需的代码片段。基于以上，这里是假设只有 1 个服务器的工作片段：

您需要使用 连接到 redis allowAdmin=true，获取此类选项的一种方法是将 AllowAdmin 分配给已解析的字符串：

var options = ConfigurationOptions.Parse("server:6379");
options.AllowAdmin = true;
var redis = ConnectionMultiplexer.Connect(options);

然后刷新所有数据库：

var endpoints = redis.GetEndPoints();
var server = redis.GetServer(endpoints[0]);
server.FlushAllDatabases();

以上适用于任何 redis 部署，而不仅仅是 Azure。