Autofac - IHTTPClientFactory多线程

Question

我正在使用NET Framework4.7.2与Autofac和Topshelf，并且我已经实现了一个HTTPClient，如下所示：

private static IContainer BuildContainer() {

    NameValueCollection anexiaADSettings = (NameValueCollection)ConfigurationManager.GetSection("AnexiaADSettings");

    var services = new ServiceCollection();
    services.AddHttpClient("API", c => {
        c.BaseAddress = new Uri(Settings["APIUrl"]);
        c.DefaultRequestHeaders.Add("Authorization", "Token " + Settings["APIToken"]);
        c.DefaultRequestHeaders.Accept.Clear();
        c.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
    });

    var providerFactory = new AutofacServiceProviderFactory();
    ContainerBuilder builder2 = providerFactory.CreateBuilder(services);

    //Builder Settings

    var container = builder2.Build();

    return container;

}

在我的Worker类中，我的构造函数看起来像：

private readonly ILogger _log;
private readonly IHttpClientFactory _clientFactory;

public LDAP(ILogger log, IHttpClientFactory clientFactory) {
    this._log = log;
    this._clientFactory = clientFactory;
}

我在一个带有以下参数的多线程foreach循环中调用我的httpClient：

var httpClient = _clientFactory.CreateClient("API");
test= await httpClient.GetFromJsonAsync<Models.GSObject>(uri);

问题是，foreach循环启动了多次，但显然只有一个活动的httpClient实例。如果我使用10个线程执行该方法，则GetFromJsonAsync将按顺序运行。如果第一个调用已经执行，它将转到下一个调用，依此类推。httpClient不应该获得与我触发foreach循环相同数量的实例吗？

编辑:这是当前执行的循环，最多有10个线程：

        var taskThrottler = new SemaphoreSlim(initialCount: 10);
        var compareTasks = new List<Task>();

        foreach (var User in Users.data.data) {

            await taskThrottler.WaitAsync();

            compareTasks.Add(
                Task.Run(async () => {
                    try {
                        await _helper.CompareUsersAsync(_settings, adUsers, gsUser.identifier);
                    }
                    finally {
                        taskThrottler.Release();
                    }
                })
            );
        }

CompareUsersAsync方法如下所示：

    public async Task CompareUsersAsync(Settings settings, List<Models.ADUser> adUsers, string identifier) {

        var httpClient = _clientFactory.CreateClient("API");
        
        try {
            string uri = "api/request.json/" + identifier;

            
            Models.GSADUser gsUser = await httpClient.GetFromJsonAsync<Models.GSADUser>(uri);

//Removed the rest of the code.

Answer 1

我已经找到了解决方案。到同一服务器的连接的默认最大值设置为2。如果你想增加这个值，你必须定义一个ServicePointManager，如下所示：

        ServicePointManager.DefaultConnectionLimit = 20;

        var services = new ServiceCollection();
        services.AddHttpClient("EngineAPI", c => {
            c.BaseAddress = new Uri("URL");
            c.DefaultRequestHeaders.Add("Authorization", "Token " + settings["APIToken"]);
            c.DefaultRequestHeaders.Accept.Clear();
            c.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
        });

在这种情况下，最多允许20个连接到同一个端点。