public void EDR_SpotFall()
{
TestClock clock = new TestClock();
TestScheduler scheduler = new TestScheduler(clock);
ExponentiallyDecayingReservoir reservoir = new ExponentiallyDecayingReservoir(1000, 0.015, clock, scheduler);
int valuesRatePerMinute = 10;
int valuesIntervalMillis = (int)(TimeUnit.Minutes.ToMilliseconds(1) / valuesRatePerMinute);
// mode 1: steady regime for 120 minutes
for (int i = 0; i < 120 * valuesRatePerMinute; i++)
{
reservoir.Update(9998);
clock.Advance(TimeUnit.Milliseconds, valuesIntervalMillis);
}
// switching to mode 2: 10 minutes more with the same rate, but smaller value
for (int i = 0; i < 10 * valuesRatePerMinute; i++)
{
reservoir.Update(178);
clock.Advance(TimeUnit.Milliseconds, valuesIntervalMillis);
}
// expect that quantiles should be more about mode 2 after 10 minutes
reservoir.Snapshot.Percentile95.Should().Be(178);
}
public TestModule(TestClock clock)
: base("/test")
{
Get["/action"] = _ =>
{
clock.Advance(TimeUnit.Milliseconds, 100);
return(Response.AsText("response"));
};
Post["/post"] = _ =>
{
clock.Advance(TimeUnit.Milliseconds, 200);
return(HttpStatusCode.OK);
};
Put["/put"] = _ =>
{
clock.Advance(TimeUnit.Milliseconds, 200);
return(HttpStatusCode.OK);
};
Patch["/patch"] = _ =>
{
clock.Advance(TimeUnit.Milliseconds, 200);
return(HttpStatusCode.OK);
};
Get["/error"] = _ => { throw new InvalidOperationException(); };
}
public void TimerMetric_CanTrackTime()
{
using (timer.NewContext())
{
clock.Advance(TimeUnit.Milliseconds, 100);
}
timer.Value.Histogram.Count.Should().Be(1);
timer.Value.Histogram.Max.Should().Be(TimeUnit.Milliseconds.ToNanoseconds(100));
}
public void MeterMetric_CanCalculateMeanRate()
{
meter.Mark();
clock.Advance(TimeUnit.Seconds, 1);
meter.Value.MeanRate.Should().Be(1);
clock.Advance(TimeUnit.Seconds, 1);
meter.Value.MeanRate.Should().Be(0.5);
}
public void apdex_score_should_be_between_zero_and_one()
{
const double apdexTSeconds = 0.5;
const int fromMilliSeconds = 20;
const int toMilliSeconds = 5000;
const int sampleSize = 1024;
var random = new Random();
var clock = new TestClock();
IApdexMetric apdexMetric = new ApdexMetric(SamplingType.ExponentiallyDecaying, sampleSize,
Constants.ReservoirSampling.DefaultExponentialDecayFactor, clock, apdexTSeconds, false);
foreach (var requestNumber in Enumerable.Range(0, 1000))
{
using (apdexMetric.NewContext())
{
clock.Advance(TimeUnit.Milliseconds, random.Next(fromMilliSeconds, toMilliSeconds));
}
}
var score = apdexMetric.GetValue().Score;
score.Should().BeGreaterOrEqualTo(0);
score.Should().BeLessOrEqualTo(1);
}
public void MeterCanCalculateMeanRate()
{
TestClock clock = new TestClock();
TestScheduler scheduler = new TestScheduler(clock);
var meter = new MeterMetric(clock, scheduler);
meter.Mark();
clock.Advance(TimeUnit.Seconds, 1);
meter.Value.MeanRate.Should().Be(1);
clock.Advance(TimeUnit.Seconds, 1);
meter.Value.MeanRate.Should().Be(0.5);
}
public void apdex_score_should_be_between_zero_and_one()
{
const double apdexTSeconds = 0.5;
const int fromMilliSeconds = 20;
const int toMilliSeconds = 5000;
var random = new Random();
var clock = new TestClock();
var reservoir = new Lazy <IReservoir>(() => new DefaultForwardDecayingReservoir());
IApdexMetric apdexMetric = new DefaultApdexMetric(reservoir, apdexTSeconds, clock, false);
foreach (var unused in Enumerable.Range(0, 1000))
{
using (apdexMetric.NewContext())
{
clock.Advance(TimeUnit.Milliseconds, random.Next(fromMilliSeconds, toMilliSeconds));
}
}
var score = apdexMetric.GetValue().Score;
score.Should().BeGreaterOrEqualTo(0);
score.Should().BeLessOrEqualTo(1);
}
public void can_calculate_the_hit_ratio_as_a_guage_with_one_min_rate_as_default()
{
var clock = new TestClock();
var scheduler = new TestTaskScheduler(clock);
var cacheHitMeter = new DefaultMeterMetric(clock, scheduler);
var dbQueryTimer = new DefaultTimerMetric(new DefaultAlgorithmRReservoir(1028), clock);
foreach (var index in Enumerable.Range(0, 1000))
{
using (dbQueryTimer.NewContext())
{
clock.Advance(TimeUnit.Milliseconds, 100);
}
if (index % 2 == 0)
{
cacheHitMeter.Mark();
}
}
var cacheHitRatioGauge = new HitRatioGauge(cacheHitMeter, dbQueryTimer);
cacheHitRatioGauge.Value.Should().BeGreaterThan(0.0);
}
public void TimerContextRecordsTimeOnlyOnFirstDispose()
{
TestClock clock = new TestClock();
TestScheduler scheduler = new TestScheduler(clock);
TimerMetric timer = new TimerMetric(SamplingType.LongTerm, new MeterMetric(clock, scheduler), clock);
var context = timer.NewContext();
clock.Advance(TimeUnit.Milliseconds, 100);
using (context) { }
clock.Advance(TimeUnit.Milliseconds, 100);
using (context) { }
timer.Value.Histogram.Count.Should().Be(1);
timer.Value.Histogram.Max.Should().Be(TimeUnit.Milliseconds.ToNanoseconds(100));
}
public void EDR_QuantiliesShouldBeBasedOnWeights()
{
TestClock clock = new TestClock();
TestScheduler scheduler = new TestScheduler(clock);
ExponentiallyDecayingReservoir reservoir = new ExponentiallyDecayingReservoir(1000, 0.015, clock, scheduler);
for (int i = 0; i < 40; i++)
{
reservoir.Update(177);
}
clock.Advance(TimeUnit.Seconds, 120);
for (int i = 0; i < 10; i++)
{
reservoir.Update(9999);
}
reservoir.Snapshot.Size.Should().Be(50);
// the first added 40 items (177) have weights 1
// the next added 10 items (9999) have weights ~6
// so, it's 40 vs 60 distribution, not 40 vs 10
reservoir.Snapshot.Median.Should().Be(9999);
reservoir.Snapshot.Percentile75.Should().Be(9999);
}
public TestModule(TestClock clock)
: base("/test")
{
Get["/action"] = _ =>
{
clock.Advance(TimeUnit.Milliseconds, 100);
return Response.AsText("response");
};
Post["/post"] = _ =>
{
clock.Advance(TimeUnit.Milliseconds, 200);
return HttpStatusCode.OK;
};
Get["/error"] = _ => { throw new InvalidOperationException(); };
}
private static void RunSamples(IEnumerable <int> satisfiedRequestsDurations, IApdexMetric apdexMetric, TestClock clock)
{
foreach (var duration in satisfiedRequestsDurations)
{
using (apdexMetric.NewContext())
{
clock.Advance(TimeUnit.Milliseconds, duration);
}
}
}
public TestModule(TestClock clock)
: base("/test")
{
this.MetricForRequestTimeAndResponseSize("ActionRequest", "Get", "/");
this.MetricForRequestSize("RequestSize", "Put", "/");
Get["/action"] = _ =>
{
clock.Advance(TimeUnit.Milliseconds, 100);
return(Response.AsText("response"));
};
Get["/contentWithLength"] = _ =>
{
clock.Advance(TimeUnit.Milliseconds, 100);
return(Response.AsText("response").WithHeader("Content-Length", "100"));
};
Put["/size"] = _ => HttpStatusCode.OK;
}
public TestModule(TestClock clock)
: base("/test")
{
this.MetricForRequestTimeAndResponseSize("Action Request", "Get", "/");
this.MetricForRequestSize("Request Size", "Put", "/");
Get["/action"] = _ =>
{
clock.Advance(TimeUnit.Milliseconds, 100);
return Response.AsText("response");
};
Get["/contentWithLength"] = _ =>
{
clock.Advance(TimeUnit.Milliseconds, 100);
return Response.AsText("response").WithHeader("Content-Length", "100");
};
Put["/size"] = _ => HttpStatusCode.OK;
}
public void EDR_longPeriodsOfInactivityShouldNotCorruptSamplingState()
{
TestClock clock = new TestClock();
TestScheduler scheduler = new TestScheduler(clock);
ExponentiallyDecayingReservoir reservoir = new ExponentiallyDecayingReservoir(10, 0.015, clock, scheduler);
// add 1000 values at a rate of 10 values/second
for (int i = 0; i < 1000; i++)
{
reservoir.Update(1000 + i);
clock.Advance(TimeUnit.Milliseconds, 100);
}
reservoir.Snapshot.Size.Should().Be(10);
reservoir.Snapshot.Values.Should().OnlyContain(v => 1000 <= v && v < 2000);
// wait for 15 hours and add another value.
// this should trigger a rescale. Note that the number of samples will be reduced to 2
// because of the very small scaling factor that will make all existing priorities equal to
// zero after rescale.
clock.Advance(TimeUnit.Hours, 15);
reservoir.Update(2000);
var snapshot = reservoir.Snapshot;
snapshot.Size.Should().Be(2);
snapshot.Values.Should().OnlyContain(v => 1000 <= v && v < 3000);
// add 1000 values at a rate of 10 values/second
for (int i = 0; i < 1000; i++)
{
reservoir.Update(3000 + i);
clock.Advance(TimeUnit.Milliseconds, 100);
}
var finalSnapshot = reservoir.Snapshot;
finalSnapshot.Size.Should().Be(10);
// TODO: double check the Skip first value - sometimes first value is 2000 - which might or not be correct
finalSnapshot.Values.Skip(1).Should().OnlyContain(v => 3000 <= v && v < 4000);
}
public void EDRlongPeriodsOfInactivityShouldNotCorruptSamplingState()
{
TestClock clock = new TestClock();
TestScheduler scheduler = new TestScheduler(clock);
ExponentiallyDecayingReservoir reservoir = new ExponentiallyDecayingReservoir(10, 0.015, clock, scheduler);
// add 1000 values at a rate of 10 values/second
for (int i = 0; i < 1000; i++)
{
reservoir.Update(1000 + i);
clock.Advance(TimeUnit.Milliseconds, 100);
}
reservoir.Snapshot.Size.Should().Be(10);
reservoir.Snapshot.Values.Should().OnlyContain(v => 1000 <= v && v < 2000);
// wait for 15 hours and add another value.
// this should trigger a rescale. Note that the number of samples will be reduced to 2
// because of the very small scaling factor that will make all existing priorities equal to
// zero after rescale.
clock.Advance(TimeUnit.Hours, 15);
reservoir.Update(2000);
var snapshot = reservoir.Snapshot;
snapshot.Size.Should().Be(2);
snapshot.Values.Should().OnlyContain(v => 1000 <= v && v < 3000);
// add 1000 values at a rate of 10 values/second
for (int i = 0; i < 1000; i++)
{
reservoir.Update(3000 + i);
clock.Advance(TimeUnit.Milliseconds, 100);
}
var finalSnapshot = reservoir.Snapshot;
finalSnapshot.Size.Should().Be(10);
// TODO: double check the Skip first value - sometimes first value is 2000 - which might or not be correct
finalSnapshot.Values.Skip(1).Should().OnlyContain(v => 3000 <= v && v < 4000);
}
public void TimerCanTrackTime()
{
TestClock clock = new TestClock();
TestScheduler scheduler = new TestScheduler(clock);
TimerMetric timer = new TimerMetric(SamplingType.LongTerm, new MeterMetric(clock, scheduler), clock);
using (timer.NewContext())
{
clock.Advance(TimeUnit.Milliseconds, 100);
}
timer.Value.Histogram.Count.Should().Be(1);
timer.Value.Histogram.Max.Should().Be(TimeUnit.Milliseconds.ToNanoseconds(100));
}
public void MeterCanComputeRates()
{
TestClock clock = new TestClock();
TestScheduler scheduler = new TestScheduler(clock);
var meter = new MeterMetric(clock, scheduler);
meter.Mark();
clock.Advance(TimeUnit.Seconds, 10);
meter.Mark(2);
var value = meter.Value;
value.MeanRate.Should().BeApproximately(0.3, 0.001);
value.OneMinuteRate.Should().BeApproximately(0.1840, 0.001);
value.FiveMinuteRate.Should().BeApproximately(0.1966, 0.001);
value.FifteenMinuteRate.Should().BeApproximately(0.1988, 0.001);
}