Sampler Performance Testing (open-telemetry#175)

sdk/test/trace/BUILD

@@ -1,3 +1,5 @@
+load("//bazel:otel_cc_benchmark.bzl", "otel_cc_benchmark")
+
 cc_test(
     name = "tracer_provider_test",
     srcs = [
@@ -81,8 +83,14 @@ cc_test(
         "probability_sampler_test.cc",
     ],
     deps = [
-        "//sdk/src/trace",
         "//sdk/src/common:random",
+        "//sdk/src/trace",
         "@com_google_googletest//:gtest_main",
     ],
 )
+
+otel_cc_benchmark(
+    name = "sampler_benchmark",
+    srcs = ["sampler_benchmark.cc"],
+    deps = ["//sdk/src/trace"],
+)

sdk/test/trace/CMakeLists.txt

@@ -1,8 +1,20 @@
-foreach(testname tracer_provider_test span_data_test simple_processor_test
-                 tracer_test always_off_sampler_test always_on_sampler_test 
-                 parent_or_else_sampler_test probability_sampler_test)
+foreach(
+  testname
+  tracer_provider_test
+  span_data_test
+  simple_processor_test
+  tracer_test
+  always_off_sampler_test
+  always_on_sampler_test
+  parent_or_else_sampler_test
+  probability_sampler_test)
   add_executable(${testname} "${testname}.cc")
-  target_link_libraries(${testname} ${GTEST_BOTH_LIBRARIES}
-                        ${CMAKE_THREAD_LIBS_INIT} opentelemetry_common opentelemetry_trace)
+  target_link_libraries(
+    ${testname} ${GTEST_BOTH_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT}
+    opentelemetry_common opentelemetry_trace)
   gtest_add_tests(TARGET ${testname} TEST_PREFIX trace. TEST_LIST ${testname})
 endforeach()
+
+add_executable(sampler_benchmark sampler_benchmark.cc)
+target_link_libraries(sampler_benchmark benchmark::benchmark
+                      ${CMAKE_THREAD_LIBS_INIT} opentelemetry_trace)

sdk/test/trace/sampler_benchmark.cc

@@ -0,0 +1,180 @@
+#include "opentelemetry/sdk/trace/sampler.h"
+#include "opentelemetry/sdk/trace/samplers/always_off.h"
+#include "opentelemetry/sdk/trace/samplers/always_on.h"
+#include "opentelemetry/sdk/trace/samplers/parent_or_else.h"
+#include "opentelemetry/sdk/trace/samplers/probability.h"
+#include "opentelemetry/sdk/trace/simple_processor.h"
+#include "opentelemetry/sdk/trace/span_data.h"
+#include "opentelemetry/sdk/trace/tracer.h"
+
+#include <cstdint>
+
+#include <benchmark/benchmark.h>
+
+using namespace opentelemetry::sdk::trace;
+namespace nostd  = opentelemetry::nostd;
+namespace common = opentelemetry::common;
+using opentelemetry::trace::SpanContext;
+
+/**
+ * A mock exporter that switches a flag once a valid recordable was received.
+ */
+class MockSpanExporter final : public SpanExporter
+{
+public:
+  MockSpanExporter(std::shared_ptr<std::vector<std::unique_ptr<SpanData>>> spans_received) noexcept
+      : spans_received_(spans_received)
+  {}
+
+  std::unique_ptr<Recordable> MakeRecordable() noexcept override
+  {
+    return std::unique_ptr<Recordable>(new SpanData);
+  }
+
+  ExportResult Export(const nostd::span<std::unique_ptr<Recordable>> &recordables) noexcept override
+  {
+    for (auto &recordable : recordables)
+    {
+      auto span = std::unique_ptr<SpanData>(static_cast<SpanData *>(recordable.release()));
+      if (span != nullptr)
+      {
+        spans_received_->push_back(std::move(span));
+      }
+    }
+
+    return ExportResult::kSuccess;
+  }
+
+  void Shutdown(std::chrono::microseconds timeout = std::chrono::microseconds(0)) noexcept override
+  {}
+
+private:
+  std::shared_ptr<std::vector<std::unique_ptr<SpanData>>> spans_received_;
+};
+
+namespace
+{
+// Sampler constructor used as a baseline to compare with other samplers
+void BM_AlwaysOffSamplerConstruction(benchmark::State &state)
+{
+  while (state.KeepRunning())
+  {
+    benchmark::DoNotOptimize(AlwaysOffSampler());
+  }
+}
+BENCHMARK(BM_AlwaysOffSamplerConstruction);
+
+// Sampler constructor used as a baseline to compare with other samplers
+void BM_AlwaysOnSamplerConstruction(benchmark::State &state)
+{
+  while (state.KeepRunning())
+  {
+    benchmark::DoNotOptimize(AlwaysOnSampler());
+  }
+}
+BENCHMARK(BM_AlwaysOnSamplerConstruction);
+
+void BM_ParentOrElseSamplerConstruction(benchmark::State &state)
+{
+  while (state.KeepRunning())
+  {
+    benchmark::DoNotOptimize(ParentOrElseSampler(std::make_shared<AlwaysOnSampler>()));
+  }
+}
+BENCHMARK(BM_ParentOrElseSamplerConstruction);
+
+void BM_ProbabilitySamplerConstruction(benchmark::State &state)
+{
+  while (state.KeepRunning())
+  {
+    benchmark::DoNotOptimize(ProbabilitySampler(0.01));
+  }
+}
+BENCHMARK(BM_ProbabilitySamplerConstruction);
+
+// Sampler Helper Function
+void BenchmarkShouldSampler(Sampler &sampler, benchmark::State &state)
+{
+  opentelemetry::trace::TraceId trace_id;
+  opentelemetry::trace::SpanKind span_kind = opentelemetry::trace::SpanKind::kInternal;
+
+  using M = std::map<std::string, int>;
+  M m1    = {{}};
+  opentelemetry::trace::KeyValueIterableView<M> view{m1};
+
+  while (state.KeepRunning())
+  {
+    benchmark::DoNotOptimize(sampler.ShouldSample(nullptr, trace_id, "", span_kind, view));
+  }
+}
+
+// Sampler used as a baseline to compare with other samplers
+void BM_AlwaysOffSamplerShouldSample(benchmark::State &state)
+{
+  AlwaysOffSampler sampler;
+
+  BenchmarkShouldSampler(sampler, state);
+}
+BENCHMARK(BM_AlwaysOffSamplerShouldSample);
+
+// Sampler used as a baseline to compare with other samplers
+void BM_AlwaysOnSamplerShouldSample(benchmark::State &state)
+{
+  AlwaysOnSampler sampler;
+
+  BenchmarkShouldSampler(sampler, state);
+}
+BENCHMARK(BM_AlwaysOnSamplerShouldSample);
+
+void BM_ParentOrElseSamplerShouldSample(benchmark::State &state)
+{
+  ParentOrElseSampler sampler(std::make_shared<AlwaysOnSampler>());
+
+  BenchmarkShouldSampler(sampler, state);
+}
+BENCHMARK(BM_ParentOrElseSamplerShouldSample);
+
+void BM_ProbabilitySamplerShouldSample(benchmark::State &state)
+{
+  ProbabilitySampler sampler(0.01);
+
+  BenchmarkShouldSampler(sampler, state);
+}
+BENCHMARK(BM_ProbabilitySamplerShouldSample);
+
+// Sampler Helper Function
+void BenchmarkSpanCreation(std::shared_ptr<Sampler> sampler, benchmark::State &state)
+{
+  std::shared_ptr<std::vector<std::unique_ptr<SpanData>>> spans_received(
+      new std::vector<std::unique_ptr<SpanData>>);
+
+  std::unique_ptr<SpanExporter> exporter(new MockSpanExporter(spans_received));
+  auto processor = std::make_shared<SimpleSpanProcessor>(std::move(exporter));
+  auto tracer    = std::shared_ptr<opentelemetry::trace::Tracer>(new Tracer(processor, sampler));
+
+  while (state.KeepRunning())
+  {
+    auto span = tracer->StartSpan("span");
+
+    span->SetAttribute("attr1", 3.1);
+
+    span->End();
+  }
+}
+
+// Test to measure performance for span creation
+void BM_SpanCreation(benchmark::State &state)
+{
+  BenchmarkSpanCreation(std::move(std::make_shared<AlwaysOnSampler>()), state);
+}
+BENCHMARK(BM_SpanCreation);
+
+// Test to measure performance overhead for no-op span creation
+void BM_NoopSpanCreation(benchmark::State &state)
+{
+  BenchmarkSpanCreation(std::move(std::make_shared<AlwaysOffSampler>()), state);
+}
+BENCHMARK(BM_NoopSpanCreation);
+
+}  // namespace
+BENCHMARK_MAIN();