/// <summary>
/// Replace <see cref="Sampler"/> with a new instance when parameters are updated.
/// </summary>
/// <param name="response">Response which contains either a <see cref="ProbabilisticSampler"/>
/// or <see cref="RateLimitingSampler"/>.</param>
private void UpdateRateLimitingOrProbabilisticSampler(SamplingStrategyResponse response)
{
ISampler sampler;
if (response.ProbabilisticSampling != null)
{
ProbabilisticSamplingStrategy strategy = response.ProbabilisticSampling;
sampler = new ProbabilisticSampler(strategy.SamplingRate);
}
else if (response.RateLimitingSampling != null)
{
RateLimitingSamplingStrategy strategy = response.RateLimitingSampling;
sampler = new RateLimitingSampler(strategy.MaxTracesPerSecond);
}
else
{
_metrics.SamplerParsingFailure.Inc(1);
_logger.LogError("No strategy present in response. Not updating sampler.");
return;
}
lock (_lock)
{
if (!Sampler.Equals(sampler))
{
Sampler.Close();
Sampler = sampler;
_metrics.SamplerUpdated.Inc(1);
}
}
}
public void TestParseRateLimitingSampling()
{
SamplingStrategyResponse response = _undertest.ParseJson(ReadFixture("ratelimiting_sampling.json"));
Assert.Equal(new RateLimitingSamplingStrategy(2.1), response.RateLimitingSampling);
Assert.Null(response.ProbabilisticSampling);
}
public async Task TestGetSamplingStrategy()
{
_httpClient.MakeGetRequestAsync("http://www.example.com/sampling?service=clairvoyant")
.Returns("{\"strategyType\":\"PROBABILISTIC\",\"probabilisticSampling\":{\"samplingRate\":0.001},\"rateLimitingSampling\":null}");
SamplingStrategyResponse response = await _undertest.GetSamplingStrategyAsync("clairvoyant");
Assert.NotNull(response.ProbabilisticSampling);
}
public async Task TestAllowHostPortSyntax()
{
var instance = new HttpSamplingManager(_httpClient, "example.com:80");
_httpClient.MakeGetRequestAsync("http://example.com/?service=clairvoyant")
.Returns("{\"strategyType\":\"PROBABILISTIC\",\"probabilisticSampling\":{\"samplingRate\":0.001},\"rateLimitingSampling\":null}");
SamplingStrategyResponse response = await instance.GetSamplingStrategyAsync("clairvoyant");
Assert.NotNull(response.ProbabilisticSampling);
}
public void TestUpdateToProbabilisticSampler()
{
double samplingRate = 0.55;
SamplingStrategyResponse probabilisticResponse = new SamplingStrategyResponse(
new ProbabilisticSamplingStrategy(samplingRate), null, null);
_samplingManager.GetSamplingStrategyAsync(SERVICE_NAME).Returns(probabilisticResponse);
_undertest.UpdateSampler();
Assert.Equal(new ProbabilisticSampler(samplingRate), _undertest.Sampler);
}
public void TestUpdateToRateLimitingSampler()
{
short tracesPerSecond = 22;
SamplingStrategyResponse rateLimitingResponse = new SamplingStrategyResponse(null,
new RateLimitingSamplingStrategy(tracesPerSecond), null);
_samplingManager.GetSamplingStrategyAsync(SERVICE_NAME).Returns(rateLimitingResponse);
_undertest.UpdateSampler();
Assert.Equal(new RateLimitingSampler(tracesPerSecond), _undertest.Sampler);
}
public void UpdateSampler_ShouldHandleNoMatchingStrategy()
{
//var expectedLogMessage = "No strategy present in response. Not updating sampler.";
var ssResponse = new SamplingStrategyResponse();
_mockSamplingManager.GetSamplingStrategy(Arg.Is <string>(sn => sn == _serivceName)).Returns(ssResponse);
_testingSampler.UpdateSampler();
_mockSamplerFactory.Received(0).NewRateLimitingSampler(Arg.Any <short>());
_mockSamplerFactory.Received(0).NewProbabilisticSampler(Arg.Any <double>());
_mockMetrics.Received(0).SamplerUpdated.Inc(Arg.Is <long>(d => d == 1));
_mockMetrics.Received(1).SamplerParsingFailure.Inc(Arg.Is <long>(d => d == 1));
// cannot mock extension methods :/ _mockLogger.Received(1).LogError(Arg.Is<string>(lm => lm == expectedLogMessage));
//_mockLogger.Received(1).Log(Arg.Any<LogLevel>(), Arg.Any<EventId>(), Arg.Any<string>(), Arg.Any<Exception>(), Arg.Any<Func<object, Exception, string>>());
}
public void TestParsePerOperationSampling()
{
SamplingStrategyResponse response = _undertest.ParseJson(ReadFixture("per_operation_sampling.json"));
OperationSamplingParameters actual = response.OperationSampling;
Assert.Equal(0.001, actual.DefaultSamplingProbability, 4);
Assert.Equal(0.001666, actual.DefaultLowerBoundTracesPerSecond, 4);
List <PerOperationSamplingParameters> actualPerOperationStrategies = actual.PerOperationStrategies;
Assert.Equal(2, actualPerOperationStrategies.Count);
Assert.Equal(
new PerOperationSamplingParameters("GET:/search", new ProbabilisticSamplingStrategy(1.0)),
actualPerOperationStrategies[0]);
Assert.Equal(
new PerOperationSamplingParameters("PUT:/pacifique", new ProbabilisticSamplingStrategy(0.8258308134813166)),
actualPerOperationStrategies[1]);
}
public void UpdateRateLimitingOrProbabilisticSampler_ShouldNotUpdateWhenSamplersAreTheSame()
{
var ssResponse = new SamplingStrategyResponse
{
RateLimitingSampling = new RateLimitingSamplingStrategy {
MaxTracesPerSecond = 10
}
};
_mockSamplingManager.GetSamplingStrategy(Arg.Is <string>(sn => sn == _serivceName)).Returns(ssResponse);
_mockSamplerFactory.NewRateLimitingSampler(Arg.Any <short>()).Returns(_mockSampler);
_testingSampler.UpdateSampler();
_mockSamplerFactory.Received(1)
.NewRateLimitingSampler(Arg.Is <short>(mt => mt == ssResponse.RateLimitingSampling.MaxTracesPerSecond));
_mockMetrics.Received(0).SamplerUpdated.Inc(Arg.Is <long>(d => d == 1));
}
public void UpdateSampler_ShouldHandleProbSampling()
{
var ssResponse = new SamplingStrategyResponse
{
ProbabilisticSampling = new ProbabilisticSamplingStrategy {
SamplingRate = 0.75
}
};
_mockSamplingManager.GetSamplingStrategy(Arg.Is <string>(sn => sn == _serivceName)).Returns(ssResponse);
_testingSampler.UpdateSampler();
_mockSamplingManager.Received(1).GetSamplingStrategy(Arg.Is <string>(sn => sn == _serivceName));
_mockMetrics.Received(1).SamplerRetrieved.Inc(Arg.Any <long>());
_mockSamplerFactory.Received(1)
.NewProbabilisticSampler(Arg.Is <double>(sr => sr == ssResponse.ProbabilisticSampling.SamplingRate));
}
public void UpdateSampler_ShouldHandleRateLimSampling()
{
var ssResponse = new SamplingStrategyResponse
{
RateLimitingSampling = new RateLimitingSamplingStrategy {
MaxTracesPerSecond = 10
}
};
_mockSamplingManager.GetSamplingStrategy(Arg.Is <string>(sn => sn == _serivceName)).Returns(ssResponse);
_testingSampler.UpdateSampler();
_mockSamplingManager.Received(1).GetSamplingStrategy(Arg.Is <string>(sn => sn == _serivceName));
_mockMetrics.Received(1).SamplerRetrieved.Inc(Arg.Any <long>());
_mockSamplerFactory.Received(1)
.NewRateLimitingSampler(Arg.Is <short>(mt => mt == ssResponse.RateLimitingSampling.MaxTracesPerSecond));
}
public void TestUpdateToPerOperationSamplerReplacesProbabilisticSampler()
{
var operationToSampler = new List <PerOperationSamplingParameters>();
operationToSampler.Add(new PerOperationSamplingParameters("operation",
new ProbabilisticSamplingStrategy(0.1)));
OperationSamplingParameters parameters = new OperationSamplingParameters(0.11, 0.22, operationToSampler);
SamplingStrategyResponse response = new SamplingStrategyResponse(null,
null, parameters);
_samplingManager.GetSamplingStrategyAsync(SERVICE_NAME).Returns(response);
_undertest.UpdateSampler();
PerOperationSampler perOperationSampler = new PerOperationSampler(2000, parameters, _loggerFactory);
ISampler actualSampler = _undertest.Sampler;
Assert.Equal(perOperationSampler, actualSampler);
}
/// <summary>
/// Updates <see cref="Sampler"/> to a new sampler when it is different.
/// </summary>
internal void UpdateSampler()
{
try
{
SamplingStrategyResponse response = _samplingManager.GetSamplingStrategyAsync(_serviceName)
.ConfigureAwait(false).GetAwaiter().GetResult();
_metrics.SamplerRetrieved.Inc(1);
if (response.OperationSampling != null)
{
UpdatePerOperationSampler(response.OperationSampling);
}
else
{
UpdateRateLimitingOrProbabilisticSampler(response);
}
}
catch (Exception ex)
{
_logger.LogWarning(ex, "Updating sampler failed");
_metrics.SamplerQueryFailure.Inc(1);
}
}
public void UpdateSampler_ShouldHandleOperationSampling()
{
var ssResponse = new SamplingStrategyResponse
{
OperationSampling = new PerOperationSamplingStrategies
{
DefaultSamplingProbability = 0.5,
DefaultLowerBoundTracesPerSecond = 10,
PerOperationStrategies = new List <OperationSamplingStrategy>()
}
};
_mockSamplingManager.GetSamplingStrategy(Arg.Is <string>(sn => sn == _serivceName)).Returns(ssResponse);
_testingSampler.UpdateSampler();
_mockSamplingManager.Received(1).GetSamplingStrategy(Arg.Is <string>(sn => sn == _serivceName));
_mockMetrics.Received(1).SamplerRetrieved.Inc(Arg.Any <long>());
_mockSamplerFactory.Received(1).NewPerOperationSampler(
Arg.Is <int>(mo => mo == 2000),
Arg.Is <double>(dsp => dsp == ssResponse.OperationSampling.DefaultSamplingProbability),
Arg.Is <double>(dlbtps => dlbtps == ssResponse.OperationSampling.DefaultLowerBoundTracesPerSecond),
Arg.Is <ILoggerFactory>(lf => lf == _mockLoggerFactory));
}