redis - 在 .NET Core 依赖注入(inject)中， `StackExchange.Redis.ConnectionMultiplexer` 应该是 `AddSingleton` 还是 `AddScope`？

Question

我正在使用 StackExchange.Redis 添加到 .NET Core 的 Redis 连接，它目前看起来像这样:

public static IServiceCollection AddRedisMultiplexer(
    this IServiceCollection services,
    Func<ConfigurationOptions> getOptions = null)
{
    // Get the options or assume localhost, as these will be set in Startup.ConfigureServices assume they won't change
    var options = getOptions?.Invoke() ?? ConfigurationOptions.Parse("localhost");

    // The Redis is a singleton, shared as much as possible.
    return services.AddSingleton<IConnectionMultiplexer>(provider => ConnectionMultiplexer.Connect(options));
}

然后在Startup

public void ConfigureServices(IServiceCollection services)
{
    services.AddRedisMultiplexer(() => 
        ConfigurationOptions.Parse(Configuration["ConnectionStrings:Redis"]));
    ...

这意味着我可以在任何地方使用 IConnectionMultiplexer 进行依赖注入(inject)。

我的问题是:ConnectionMultiplexer 是 designed to be reused ，所以我使用 AddSingleton 为整个应用程序保留一个实例。但是，我也可以使用 AddScoped 在请求期间使用一个。哪个更好？为什么？

Answer 1

应用程序的预期负载是多少？如果您有很多并发性，我认为使用 AddScoped 将意味着为每个请求启动和关闭连接带来很多不必要的负担。

此外，恕我直言，这些观察表明您应该使用 AddSingleton

(...) it is exceptionally rare that you would want to use a ConnectionMultiplexer briefly, as the idea is to re-use this object.

Another common use of redis is as a pub/sub message distribution tool; this is also simple, and in the event of connection failure, the ConnectionMultiplexer will handle all the details of re-subscribing to the requested channels.

此外，您将节省只有一个 ConnectionMultiplexer 实例的内存(恕我直言)。