CODEWITHSUNDEEP
c#asp.net-coreparallel-processing
Stefano Toppi
Stefano Toppi

Reputation: 656

Aspnet core parallel request max simultaneous connections

I'm trying to parallelize some calls to my api service. I found this example and it works fine. The only problem is that the server I call accepts a maximum of 10 simultaneous connections and the result is that some calls fail. How can I write this code in such a way that I am sure it does not make more than 10 simultaneous connections?

List<PlayerViewModel> p; // my list of 700 element
List<Player> listFinalPlayer = new List<Player>(); //final List
var batchSize = 100;
int numberOfBatches = (int)Math.Ceiling((double)p.Count() / batchSize);


for (int i = 0; i < numberOfBatches; i++)
{
    var currentIds = p.Skip(i * batchSize).Take(batchSize);
    var tasks = currentIds.Select(p => GetMarket(p));
    .AddRange(await Task.WhenAll(tasks));
}


public async Task<Player> GetMarket(PlayerViewModel p)
{
    try
    {
        HttpRequestMessage tirthRequest = createRequest("https://myapiprovider/v2/players/" + p.id + "/marketvalue");
        var client3 = _clientFactory.CreateClient();
        var response3 = await client3.SendAsync(tirthRequest);
        Market market = JsonConvert.DeserializeObject<Market>(await response3.Content.ReadAsStringAsync());
        Player finalPlayer = new Player();
        finalPlayer.PlayerId = id;
        finalPlayer.MarketValue = market.marketValue;
        finalPlayer.Value = Convert.ToDouble(market.marketValue) / Convert.ToDouble(1000000);
        return finalPlayer;
    } catch(Exception e)
    {
        //Here I receive to many request from server
        return new Player();
    }
}

Thanks!!

Upvotes: 0

Views: 178

Answers (1)

Stephen Cleary
Stephen Cleary

Reputation: 457027

How can I write this code in such a way that I am sure it does not make more than 10 simultaneous connections?

Throttling asynchronous code is usually done with SemaphoreSlim:

private readonly SemaphoreSlim _throttle = new SemaphoreSlim(10);
public async Task<Player> GetMarket(PlayerViewModel p)
{
  await _throttle.WaitAsync();
  try
  {
    ...
  }
  finally
  {
    _throttle.Release();
  }
}

Upvotes: 1

Related Questions