public async Task Invoke_NoThrottle_DispatchesDirectly()
{
bool nextInvoked = false;
RequestDelegate next = (ctxt) =>
{
nextInvoked = true;
ctxt.Response.StatusCode = (int)HttpStatusCode.Accepted;
return(Task.CompletedTask);
};
var options = new HttpOptions();
var middleware = new HttpThrottleMiddleware(next, _loggerFactory, TimeSpan.FromSeconds(1));
var httpContext = new DefaultHttpContext();
await middleware.Invoke(httpContext, new OptionsWrapper <HttpOptions>(_httpOptions), _requestQueue, _performanceManager.Object, _metricsLogger.Object);
Assert.True(nextInvoked);
Assert.Equal(HttpStatusCode.Accepted, (HttpStatusCode)httpContext.Response.StatusCode);
}
public async Task Invoke_MaxParallelism_RequestsAreThrottled()
{
int maxParallelism = 3;
_httpOptions = new HttpOptions
{
MaxConcurrentRequests = maxParallelism
};
_requestQueue = new HttpRequestQueue(new OptionsWrapper <HttpOptions>(_httpOptions));
int count = 0;
RequestDelegate next = async(ctxt) =>
{
if (Interlocked.Increment(ref count) > maxParallelism)
{
throw new Exception($"Max parallelism of {maxParallelism} exceeded. Current parallelism: {count}");
}
await Task.Delay(100);
Interlocked.Decrement(ref count);
ctxt.Response.StatusCode = (int)HttpStatusCode.Accepted;
};
var middleware = new HttpThrottleMiddleware(next, _loggerFactory, TimeSpan.FromSeconds(1));
// expect all requests to succeed
var tasks = new List <Task>();
var httpContexts = new List <HttpContext>();
for (int i = 0; i < 20; i++)
{
var httpContext = new DefaultHttpContext();
httpContexts.Add(httpContext);
tasks.Add(middleware.Invoke(httpContext, new OptionsWrapper <HttpOptions>(_httpOptions), _requestQueue, _performanceManager.Object, _metricsLogger.Object));
}
await Task.WhenAll(tasks);
Assert.True(httpContexts.All(p => (HttpStatusCode)p.Response.StatusCode == HttpStatusCode.Accepted));
}
public async Task Invoke_HostIsOverloaded_RequestsAreRejected()
{
_httpOptions = new HttpOptions
{
DynamicThrottlesEnabled = true
};
_requestQueue = new HttpRequestQueue(new OptionsWrapper <HttpOptions>(_httpOptions));
bool isOverloaded = false;
_performanceManager.Setup(p => p.PerformanceCountersExceeded(It.IsAny <Collection <string> >(), It.IsAny <ILogger>())).Returns(() => isOverloaded);
RequestDelegate next = async(ctxt) =>
{
await Task.Delay(100);
ctxt.Response.StatusCode = (int)HttpStatusCode.Accepted;
};
var middleware = new HttpThrottleMiddleware(next, _loggerFactory, TimeSpan.FromMilliseconds(50));
var tasks = new List <Task>();
var httpContexts = new List <HttpContext>();
for (int i = 0; i < 10; i++)
{
if (i == 7)
{
isOverloaded = true;
}
var httpContext = new DefaultHttpContext();
httpContexts.Add(httpContext);
await middleware.Invoke(httpContext, new OptionsWrapper <HttpOptions>(_httpOptions), _requestQueue, _performanceManager.Object, _metricsLogger.Object);
}
await Task.WhenAll(tasks);
Assert.Equal(7, httpContexts.Count(p => (HttpStatusCode)p.Response.StatusCode == HttpStatusCode.Accepted));
Assert.Equal(3, httpContexts.Count(p => (HttpStatusCode)p.Response.StatusCode == HttpStatusCode.TooManyRequests));
}
public async Task Invoke_UnderLoad_RequestsAreRejected()
{
_httpOptions.DynamicThrottlesEnabled = true;
bool highLoad = false;
int highLoadQueryCount = 0;
_performanceManager.Setup(p => p.PerformanceCountersExceeded(It.IsAny <Collection <string> >(), It.IsAny <ILogger>()))
.Callback <Collection <string>, ILogger>((exceededCounters, tw) =>
{
if (highLoad)
{
exceededCounters.Add("Threads");
exceededCounters.Add("Processes");
}
}).Returns(() =>
{
highLoadQueryCount++;
return(highLoad);
});
// issue some requests while not under high load
for (int i = 0; i < 3; i++)
{
var httpContext = new DefaultHttpContext();
await _middleware.Invoke(httpContext, new OptionsWrapper <HttpOptions>(_httpOptions), _requestQueue, _performanceManager.Object, _metricsLogger.Object);
Assert.Equal(HttpStatusCode.Accepted, (HttpStatusCode)httpContext.Response.StatusCode);
await Task.Delay(100);
}
Assert.Equal(1, highLoadQueryCount);
Assert.Equal(0, _throttleMetricCount);
// signal high load and verify requests are rejected
await Task.Delay(1000);
highLoad = true;
for (int i = 0; i < 3; i++)
{
var httpContext = new DefaultHttpContext();
await _middleware.Invoke(httpContext, new OptionsWrapper <HttpOptions>(_httpOptions), _requestQueue, _performanceManager.Object, _metricsLogger.Object);
httpContext.Response.Headers.TryGetValue(ScriptConstants.AntaresScaleOutHeaderName, out StringValues values);
string scaleOutHeader = values.Single();
Assert.Equal("1", scaleOutHeader);
Assert.Equal(HttpStatusCode.TooManyRequests, (HttpStatusCode)httpContext.Response.StatusCode);
await Task.Delay(100);
}
Assert.Equal(2, highLoadQueryCount);
Assert.Equal(3, _throttleMetricCount);
var log = _loggerProvider.GetAllLogMessages().Last();
Assert.Equal("Thresholds for the following counters have been exceeded: [Threads, Processes]", log.FormattedMessage);
await Task.Delay(1000);
highLoad = false;
for (int i = 0; i < 3; i++)
{
var httpContext = new DefaultHttpContext();
await _middleware.Invoke(httpContext, new OptionsWrapper <HttpOptions>(_httpOptions), _requestQueue, _performanceManager.Object, _metricsLogger.Object);
Assert.Equal(HttpStatusCode.Accepted, (HttpStatusCode)httpContext.Response.StatusCode);
await Task.Delay(100);
}
Assert.Equal(3, highLoadQueryCount);
Assert.Equal(3, _throttleMetricCount);
}
