When sending requests in a loop, httpclient starts to be slowing

Question

I have a program that sends a request and parse the response. I want to do 1000 of requests. After 10-15 requests, Httpclient starts to be slowig, and sends a request for about 10 seconds slower, and then slower and slower. Sample code:

class a5
{
    public static HttpClient client = new HttpClient();

    public async System.Threading.Tasks.Task main()
    {
        for (int page = 0; Position < 1000; page++)
        {
            //int totalpages = await frist1(link);
            string full_json = await post_all_pages(page, link);
            var jsons = JsonConvert.DeserializeObject<Json5>(full_json);
            // Далее парсинг данных...
        }
    }
    // запрос 
    private async System.Threading.Tasks.Task<string> post_all_pages(int page, string link)
    {
        var Other_Link = link.Substring(link.LastIndexOf("/") + 1, link.Length - (link.LastIndexOf("/") + 1));

        var jsonrequest = "{\"PageSize\":" + 25 + ",\"PageNumber\":" + page + ",\"OrderBy\":\"PriceAsc\",\"HotelId\":null}";
        var content = new StringContent(jsonrequest, Encoding.UTF8, "application/json");
        var html = await client.PostAsync("https://intourist.ru/search/api/TourSearch/" + Other_Link, content);
        Console.WriteLine("{\"PageSize\":" + 25 + ",\"PageNumber\":" + page + ",\"OrderBy\":\"PriceAsc\",\"HotelId\":null}");
        Console.WriteLine(html);
        return html.Content.ReadAsStringAsync().Result;
    }

Answer 1

List<Task<string>> alltasks = new List<Task<string>>();

for (int page = 0; Position < 1000; page++)
{
    //int totalpages = await frist1(link);
    Task<String> t =  post_all_pages(page, link);
    alltasks.add(t);
    //var jsons = JsonConvert.DeserializeObject<Json5>(full_json);
    // Далее парсинг данных...
}

Tasks.WaitAll(alltasks.ToArray());

You may want to create a async function that will calls post_all_pages, then await result and then does a JsonDeserialize.

[EDIT 07/18/2020] Using WhenAll is a better solution:

await Task.WhenAll(alltasks.ToArray());