public async Task AddsTraceKeepRateMetricToRootSpan()
{
// Traces should be dropped when both buffers are full
var calculator = new MovingAverageKeepRateCalculator(windowSize: 10, Timeout.InfiniteTimeSpan);
var tracer = new Mock <IDatadogTracer>();
tracer.Setup(x => x.DefaultServiceName).Returns("Default");
var traceContext = new TraceContext(tracer.Object);
var rootSpanContext = new SpanContext(null, traceContext, null);
var rootSpan = new Span(rootSpanContext, DateTimeOffset.UtcNow);
var childSpan = new Span(new SpanContext(rootSpanContext, traceContext, null), DateTimeOffset.UtcNow);
traceContext.AddSpan(rootSpan);
traceContext.AddSpan(childSpan);
var trace = new[] { rootSpan, childSpan };
var sizeOfTrace = ComputeSizeOfTrace(trace);
// Make the buffer size big enough for a single trace
var api = new Mock <IApi>();
api.Setup(x => x.SendTracesAsync(It.IsAny <ArraySegment <byte> >(), It.IsAny <int>()))
.ReturnsAsync(() => true);
var agent = new AgentWriter(api.Object, statsd: null, calculator, automaticFlush: false, maxBufferSize: (sizeOfTrace * 2) + SpanBuffer.HeaderSize - 1, batchInterval: 100);
// Fill both buffers
agent.WriteTrace(trace);
agent.WriteTrace(trace);
// Drop one
agent.WriteTrace(trace);
await agent.FlushTracesAsync(); // Force a flush to make sure the trace is written to the API
// Write another one
agent.WriteTrace(trace);
await agent.FlushTracesAsync(); // Force a flush to make sure the trace is written to the API
api.Verify();
api.Invocations.Clear();
// Write trace and update keep rate
calculator.UpdateBucket();
agent.WriteTrace(trace);
await agent.FlushTracesAsync(); // Force a flush to make sure the trace is written to the API
const double expectedTraceKeepRate = 0.75;
rootSpan.SetMetric(Metrics.TracesKeepRate, expectedTraceKeepRate);
var expectedData = Vendors.MessagePack.MessagePackSerializer.Serialize(trace, new FormatterResolverWrapper(SpanFormatterResolver.Instance));
await agent.FlushAndCloseAsync();
api.Verify(x => x.SendTracesAsync(It.Is <ArraySegment <byte> >(y => Equals(y, expectedData)), It.Is <int>(i => i == 1)), Times.Once);
}
public void Calculator_ShouldCalculateKeepRateCorrectly(int keep, int drop, double expected)
{
const int size = 5;
var calc = new MovingAverageKeepRateCalculator(size, Timeout.InfiniteTimeSpan);
calc.IncrementKeeps(keep);
calc.IncrementDrops(drop);
calc.UpdateBucket();
var actualRate = calc.GetKeepRate();
Assert.Equal(expected, actualRate, precision: 2);
}
