HttpClient 卡在异步任务上

Question

我有一个 HttpClient，我正在使用以下代码基于远程服务器上的文件拉取流。当线程走到第三个await时，它会在那里暂停很长时间。如果文件的大小妨碍了它们分别为 33347 kb、123665 kb 和 178688 kb，但我怀疑是这种情况，因为最后两个文件的大小相似。

// a property in a class
private HttpClient HttpClient { get; set; } = new HttpClient() { Timeout = TimeSpan.FromMilliseconds(-1) };

// in a function in that class
using Stream stationsStream = await HttpClient.GetStreamAsync("https://eddb.io/archive/v6/stations.jsonl");
using Stream systemsStream = await HttpClient.GetStreamAsync("https://eddb.io/archive/v6/systems_populated.jsonl");
// always gets stuck on the third await no matter the order.
using Stream listingStream = await HttpClient.GetStreamAsync("https://eddb.io/archive/v6/listings.csv");

我没有太多地使用 HttpClient class，但是一些理论认为 API 只允许两个连接或者 HttpClient 只能有两个。

Answer 1

我需要用 HttpClientHandler 创建 HttpClient 并将 HttpClientHandler 传递给 HttpClient 的构造函数，同时更改 HttpClientHandler 的MaxConnectionsPerServer 到更大的数字。例如：

private HttpClient HttpClient { get; set; } = new HttpClient(Handler) { Timeout = TimeSpan.FromMilliseconds(-1) };
private static HttpClientHandler Handler { get; set; } = new HttpClientHandler() { MaxConnectionsPerServer = 3 };

HttpClient 卡在异步任务上

HttpClient gets stuck on async task

c#

dotnet-httpclient