Requests using YARP are much slower

Question

I'm making API calls using Postman to some endpoint (e.g. https://example.com/api) and it takes between 150-200ms to get a response.

I'm trying to use IHttpForwarder from YARP 2.0. and suddenly my requests start to take 400-700ms to get a response. I added some events logging based on diagnosing YARP-based proxies and those are the results:

Forwarder Telemetry [13:30:40.534] => OnForwarderStage :: Stage: SendAsyncStart
Forwarder Telemetry [13:30:40.758] => OnForwarderStage :: Stage: SendAsyncStop
Forwarder Telemetry [13:30:40.966] => OnContentTransferred :: Content length: 510127, IOps: 24, Read time: 0.204, Write time: 0.003

Any idea how to fast those things up? Here is my code, which is more or less the same as in their documentation:

[ApiController]
[Route("/test")]
public class TestController : ControllerBase
{
    private readonly IHttpForwarder _forwarder;

    private readonly CustomTransformer _transformer;
    private readonly HttpMessageInvoker _httpClient;
    private readonly ForwarderRequestConfig _requestOptions;

    public TestController(IHttpForwarder forwarder)
    {
        _forwarder = forwarder;

        // Setup our own request transform class
        _transformer = new CustomTransformer();

        // Configure our own HttpMessageInvoker for outbound calls for proxy operations
        _httpClient = new HttpMessageInvoker(new SocketsHttpHandler()
        {
            UseProxy = false,
            AllowAutoRedirect = false,
            AutomaticDecompression = DecompressionMethods.None,
            UseCookies = false,
            ActivityHeadersPropagator = new ReverseProxyPropagator(DistributedContextPropagator.Current)
        });

        // Initialize the ForwarderRequestConfig
        _requestOptions = new ForwarderRequestConfig { ActivityTimeout = TimeSpan.FromSeconds(100) };
    }

    [HttpGet]
    [Route("{**catch-all}")]
    public async Task IndexAsync()
    {
        var error = await _forwarder.SendAsync(HttpContext, "https://example.com/api/", _httpClient, _requestOptions, _transformer);
    }
}

I have tried disabling TLS/SSL certificate check, and adding some PooledConnectionLifetime to SocketsHttpHandler but without success.

Thanks for help!

Avoid creating the HttpClient in the controller constructor. You want to do that once instead of per incoming request. — davidfowl, May 15 '23 at 07:18

score 2 · Accepted Answer · answered May 18 '23 at 08:14

2

Avoid creating the HttpClient in the controller constructor. You want to do that once instead of per incoming request. Instead, register it as a singleton and pass it into the forwarder.

answered May 18 '23 at 08:14

davidfowl

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I suspect the OP doesn't know that HttpClient is thread safe, reusable and pools sockets, or just how expensive creating a new instance per request is. `adding some PooledConnectionLifetime to SocketsHttpHandler but without success.` sounds like they tried to implement the out-of-the-box behavior without realizing it – Panagiotis Kanavos May 18 '23 at 08:25

Requests using YARP are much slower

1 Answers1