为什么.net核心API取消请求？ [英] Why is my .net core API cancelling requests?
问题描述
我有一个循环的aync方法：
I have a an aync method that is looped:
private Task<HttpResponseMessage> GetResponseMessage(Region region, DateTime startDate, DateTime endDate)
{
var longLatString = $"q={region.LongLat.Lat},{region.LongLat.Long}";
var startDateString = $"{startDateQueryParam}={ConvertDateTimeToApixuQueryString(startDate)}";
var endDateString = $"{endDateQueryParam}={ConvertDateTimeToApixuQueryString(endDate)}";
var url = $"http://api?key={Config.Key}&{longLatString}&{startDateString}&{endDateString}";
return Client.GetAsync(url);
}
然后我将响应保存到我的ef核心数据库中，但是在在某些情况下，我会收到此异常消息：操作被取消
I then take the response and save it to my ef core database, however in some instances I get this Exception message: The Operaiton was canceled
我真的不明白。这是TCP握手问题吗？
I really dont understand that. This is a TCP handshake issue?
编辑：
对于上下文，我正在进行许多此类调用，对写入db的方法的响应（这也是如此之慢，令人难以置信）：
For context I am making many of these calls, passing response to the method that writes to db (which is also so slow Its unbelievable):
private async Task<int> WriteResult(Response apiResponse, Region region)
{
// since context is not thread safe we ensure we have a new one for each insert
// since a .net core app can insert data at the same time from different users different instances of context
// must be thread safe
using (var context = new DalContext(ContextOptions))
{
var batch = new List<HistoricalWeather>();
foreach (var forecast in apiResponse.Forecast.Forecastday)
{
// avoid inserting duplicates
var existingRecord = context.HistoricalWeather
.FirstOrDefault(x => x.RegionId == region.Id &&
IsOnSameDate(x.Date.UtcDateTime, forecast.Date));
if (existingRecord != null)
{
continue;
}
var newHistoricalWeather = new HistoricalWeather
{
RegionId = region.Id,
CelsiusMin = forecast.Day.Mintemp_c,
CelsiusMax = forecast.Day.Maxtemp_c,
CelsiusAverage = forecast.Day.Avgtemp_c,
MaxWindMph = forecast.Day.Maxwind_mph,
PrecipitationMillimeters = forecast.Day.Totalprecip_mm,
AverageHumidity = forecast.Day.Avghumidity,
AverageVisibilityMph = forecast.Day.Avgvis_miles,
UvIndex = forecast.Day.Uv,
Date = new DateTimeOffset(forecast.Date),
Condition = forecast.Day.Condition.Text
};
batch.Add(newHistoricalWeather);
}
context.HistoricalWeather.AddRange(batch);
var inserts = await context.SaveChangesAsync();
return inserts;
}
编辑：我正在拨打150,000个电话。我知道这是有问题的，因为所有内存都存储在内存中，甚至在保存之前就已经存在了，但这就是我试图使运行速度更快的地方。。。只有我猜我的实际编写代码正在阻塞：/
I am making 150,000 calls. I know this is questionable since It all goes in memory I guess before even doing a save but this is where I got to in trying to make this run faster... only I guess my actual writing code is blocking :/
var dbInserts = await Task.WhenAll(
getTasks // the list of all api get requests
.Select(async x => {
// parsed can be null if get failed
var parsed = await ParseApixuResponse(x.Item1); // readcontentasync and just return the deserialized json
return new Tuple<ApiResult, Region>(parsed, x.Item2);
})
.Select(async x => {
var finishedGet = await x;
if(finishedGet.Item1 == null)
{
return 0;
}
return await writeResult(finishedGet.Item1, finishedGet.Item2);
})
);
推荐答案
.net核心具有注释中回答的是DefaultConnectionLimit 设置。
.net core has a DefaultConnectionLimit setting as answered in comments.
这限制了到特定域的传出连接，以确保不占用所有端口等。
this limits outgoing connections to specific domains to ensure all ports are not taken etc.
我的并行工作不正确，导致它超出了限制-我所读的内容在.net内核上不应为2，而是-并且导致连接关闭，然后接收响应。
i did my parallel work incorrectly causing it to go over the limit - which everything i read says should not be 2 on .net core but it was - and that caused connections to close before receiving responses.
我把它做的更大，并行工作正确，然后又降低了。
I made it greater, did parallel work correctly, lowered it again.
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