How to get a Fast .Net Http Request

Question

I need an Http request that I can use in .Net which takes under 100 ms. I\'m able to achieve this in my browser so I really don\'t see why this is such a problem in code.

Answer 1

When benchmarking, it is best to discard at least the first two timings as they are likely to skew the results:

• Timing 1: Dominated by JIT overhead i.e. the process of turning byte code into native code.
• Timing 2: A possible optimization pass for the JIT'd code.

Timings after this will reflect repeat performance much better.

The following is an example of a test harness that will automatically disregard JIT and optimization passes, and run a test a set number of iterations before taking an average to assert performance. As you can see the JIT pass takes a substantial amount of time.

JIT:410.79ms

Optimize:0.98ms.

Average over 10 iterations:0.38ms

Code:

[Test]
public void WebRequest_Should_Get_Html_Quickly()
{
    private const int TestIterations = 10;
    private const int MaxMilliseconds = 100;

    Action test = () =>
    {
       WebRequest.Create("http://localhost/iisstart.htm").GetResponse();
    };

    AssertTimedTest(TestIterations, MaxMilliseconds, test);
}

private static void AssertTimedTest(int iterations, int maxMs, Action test)
{
    double jit = Execute(test); //disregard jit pass
    Console.WriteLine("JIT:{0:F2}ms.", jit);

    double optimize = Execute(test); //disregard optimize pass
    Console.WriteLine("Optimize:{0:F2}ms.", optimize);

    double totalElapsed = 0;
    for (int i = 0; i < iterations; i++) totalElapsed += Execute(test);

    double averageMs = (totalElapsed / iterations);
    Console.WriteLine("Average:{0:F2}ms.", averageMs);
    Assert.Less(averageMs, maxMs, "Average elapsed test time.");
}

private static double Execute(Action action)
{
    Stopwatch stopwatch = Stopwatch.StartNew();
    action();
    return stopwatch.Elapsed.TotalMilliseconds;
}