RedLock.net 使用 StackExchange.Redis 的連線設定

最近專案發現在大量並行處理時會出現重複建立資料的狀況，因為這個專案本來就是設計來進行分散式作業，同時會建立好幾個 instance 在不同的 pod 中，所以預計使用分散式鎖: RedLock.net 來解決問題，關於 RedLock.net 的基本用法在可以參考之前筆記使用 RedLock.net 搭配 redis 達成分散式 Lock

團隊中不少專案為了加快資料顯示的速度都使用 redis 做為 cache，其中 redis 的存取都是使用 StackExchange.Redis，而這與 RedLock.net 相依一致，為了統一連線管理為了避免建立多餘的連線，所以打算共用原有的 StackExchange.Redis multiplexer connection，簡單紀錄一下用法

ASP.NET Core 註冊 StackExchange.Redis 的做法可以參考之前筆記 ASP.NET Core 中 StackExchange.Redis 的註冊與使用方式

基本環境設定

mac Big Sur 11.6
.NET Core SDK 5.0.401
NuGet packages
- StackExchange.Redis.Extensions.AspNetCore 7.1.1
- StackExchange.Redis.Extensions.System.Text.Json 7.1.1
- StackExchange.Redis 2.2.79
- RedLock.net 2.3.1

設定與使用方式

使用 IConnectionMultiplexer 註冊 RedLockFactory

Startup.cs 中的 ConfigureServices

services.AddSingleton<IConnectionMultiplexer>(ConnectionMultiplexer.Connect(Configuration.GetValue<string>("RedisConnection")));
        
services.AddSingleton<IDistributedLockFactory,RedLockFactory>(sp =>
    {
        var redis = sp.GetService<IConnectionMultiplexer>();
        var multiplexers = new List<RedLockMultiplexer>
        {
            (ConnectionMultiplexer)redis.GetDatabase().Multiplexer
        };
        return RedLockFactory.Create( multiplexers);
    });

使用方式

public TestController : Controller
{
    private readonly IConnectionMultiplexer _connectionMultiplexer;
    private readonly IDistributedLockFactory _redlockFactory;

    public TestController(IConnectionMultiplexer multiplexer,IDistributedLockFactory redlockFactory)
    {
        _connectionMultiplexer = multiplexer;
        _redlockFactory = redlockFactory;

        const string resource = "yowko-test-redlock";
        var expiry = TimeSpan.FromSeconds(30);

        using var redLock =  _redlockFactory.CreateLockAsync(resource, expiry).ConfigureAwait(false).GetAwaiter().GetResult();

        if (redLock.IsAcquired)
        {
            Thread.Sleep(TimeSpan.FromSeconds(10));
        }
    }
}

使用 IDatabase 註冊 RedLockFactory

Startup.cs 中的 ConfigureServices

services.AddSingleton<IDatabase>(ConnectionMultiplexer.Connect(Configuration.GetValue<string>("RedisConnection")).GetDatabase(0));

services.AddSingleton<IDistributedLockFactory,RedLockFactory>(sp =>
    {
        var redisDb = sp.GetService<IDatabase>();
        var multiplexers = new List<RedLockMultiplexer>
        {
            (ConnectionMultiplexer)redisDb.Multiplexer
        };
        return RedLockFactory.Create( multiplexers);
    });

使用方式

public TestController : Controller
{
    private readonly IDatabase _redisDb
    private readonly IDistributedLockFactory _redlockFactory;

    public TestController(IDatabase redisDb, IDistributedLockFactory redlockFactory)
    {
        _redisDb = redisDb;
        _redlockFactory = redlockFactory;

        const string resource = "yowko-test-redlock";
        var expiry = TimeSpan.FromSeconds(30);

        using var redLock =  _redlockFactory.CreateLockAsync(resource, expiry).ConfigureAwait(false).GetAwaiter().GetResult();

        if (redLock.IsAcquired)
        {
            Thread.Sleep(TimeSpan.FromSeconds(10));
        }
    }
}

使用擴充方法註冊

Startup.cs 中的 ConfigureServices

services.AddStackExchangeRedisExtensions<SystemTextJsonSerializer>(Configuration.GetSection("RedisConnection").Get<RedisConfiguration>());
            
services.AddSingleton<IDistributedLockFactory,RedLockFactory>(sp =>
    {
        var redis = sp.GetService<IRedisCacheClient>();
        var multiplexers = new List<RedLockMultiplexer>
        {
            (ConnectionMultiplexer)redis.GetDbFromConfiguration().Database.Multiplexer
        };
        return RedLockFactory.Create( multiplexers);
    });

使用方式

public TestController : Controller
{
    private readonly IRedisCacheClient _redisCacheClient;
    private readonly IDistributedLockFactory _redlockFactory;

    public TestController(IRedisCacheClient redisCacheClient,IDistributedLockFactory redlockFactory)
    {
        _redisCacheClient = redisCacheClient;
        _redlockFactory = redlockFactory;

        const string resource = "yowko-test-redlock";
        var expiry = TimeSpan.FromSeconds(30);

        using var redLock =  _redlockFactory.CreateLockAsync(resource, expiry).ConfigureAwait(false).GetAwaiter().GetResult();

        if (redLock.IsAcquired)
        {
            Thread.Sleep(TimeSpan.FromSeconds(10));
        }
    }
}

心得

實際效果

當然實際應用上可以將 RedlockFactory 的建立移至各個實際應用位置，但如果不是對整個程式結構很有把握，可能會有重複 create 的疑慮，所以還是統一註冊管理比較好確保 singleton

文章目錄