[EXPORTER] add OTLP HTTP metric exporter benchmark

exporters/otlp/CMakeLists.txt

@@ -999,3 +999,14 @@ if(BUILD_TESTING)
       TEST_LIST otlp_file_metric_exporter_factory_test)
   endif()
 endif() # BUILD_TESTING
+
+if(WITH_BENCHMARK AND WITH_OTLP_HTTP)
+  add_executable(otlp_http_metric_exporter_benchmark
+                 benchmark/otlp_http_metric_exporter_benchmark.cc)
+
+  target_link_libraries(
+    otlp_http_metric_exporter_benchmark
+    PRIVATE opentelemetry_exporter_otlp_http_metric opentelemetry_metrics
+            opentelemetry_resources benchmark::benchmark
+            ${CMAKE_THREAD_LIBS_INIT})
+endif()

exporters/otlp/benchmark/otlp_http_metric_exporter_benchmark.cc

@@ -0,0 +1,128 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#include <benchmark/benchmark.h>
+
+#include <chrono>
+#include <cstddef>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "opentelemetry/exporters/otlp/otlp_http.h"
+#include "opentelemetry/exporters/otlp/otlp_http_metric_exporter.h"
+#include "opentelemetry/exporters/otlp/otlp_http_metric_exporter_options.h"
+
+#include "opentelemetry/nostd/string_view.h"
+
+#include "opentelemetry/sdk/common/attribute_utils.h"
+#include "opentelemetry/sdk/common/global_log_handler.h"
+
+#include "opentelemetry/sdk/instrumentationscope/instrumentation_scope.h"
+
+#include "opentelemetry/sdk/metrics/data/metric_data.h"
+#include "opentelemetry/sdk/metrics/data/point_data.h"
+#include "opentelemetry/sdk/metrics/export/metric_producer.h"
+#include "opentelemetry/sdk/metrics/instruments.h"
+#include "opentelemetry/sdk/resource/resource.h"
+
+using InstrumentationScope = opentelemetry::sdk::instrumentationscope::InstrumentationScope;
+using namespace opentelemetry::sdk::metrics;
+using namespace opentelemetry::exporter::otlp;
+
+// Create ResourceMetrics with a single metric containing 'n' data points
+static ResourceMetrics MakeMetrics(std::size_t n_points)
+{
+  ResourceMetrics rm;
+  static const opentelemetry::sdk::resource::Resource resource =
+      opentelemetry::sdk::resource::Resource::Create({{"service.name", "metric-benchmark"}});
+  rm.resource_ = &resource;
+
+  static auto scope = InstrumentationScope::Create("benchmark", "1.0.0");
+  ScopeMetrics scope_metrics;
+  scope_metrics.scope_ = scope.get();
+
+  MetricData metric;
+  metric.instrument_descriptor.name_ = "cpu.utilization";
+  metric.instrument_descriptor.unit_ = "1";
+  metric.instrument_descriptor.type_ = InstrumentType::kCounter;
+  metric.aggregation_temporality     = AggregationTemporality::kCumulative;
+
+  for (std::size_t i = 0; i < n_points; ++i)
+  {
+    SumPointData sum;
+    sum.value_        = static_cast<double>(i);
+    sum.is_monotonic_ = true;
+
+    PointDataAttributes p;
+    p.attributes = {{"core", static_cast<int>(i)}};
+    p.point_data = sum;
+
+    metric.point_data_attr_.push_back(p);
+  }
+
+  scope_metrics.metric_data_.push_back(metric);
+  rm.scope_metric_data_.push_back(scope_metrics);
+  return rm;
+}
+
+// Benchmark Export() using Binary encoding
+static void BM_OtlpHttpMetricExporter_Export_Binary(benchmark::State &state)
+{
+  OtlpHttpMetricExporterOptions opts;
+  opts.url                       = "http://localhost:4318/v1/metrics";
+  opts.content_type              = HttpRequestContentType::kBinary;
+  opts.timeout                   = std::chrono::milliseconds(1);
+  opts.retry_policy_max_attempts = 0;
+
+  OtlpHttpMetricExporter exporter(opts);
+  auto metrics = MakeMetrics(state.range(0));
+
+  for (auto _ : state)
+  {
+    benchmark::DoNotOptimize(exporter.Export(metrics));
+  }
+
+  state.SetItemsProcessed(state.iterations() * state.range(0));
+}
+
+// Benchmark Export() using JSON encoding
+static void BM_OtlpHttpMetricExporter_Export_Json(benchmark::State &state)
+{
+  OtlpHttpMetricExporterOptions opts;
+  opts.url                       = "http://localhost:4318/v1/metrics";
+  opts.content_type              = HttpRequestContentType::kJson;
+  opts.timeout                   = std::chrono::milliseconds(1);
+  opts.retry_policy_max_attempts = 0;
+
+  OtlpHttpMetricExporter exporter(opts);
+  auto metrics = MakeMetrics(state.range(0));
+
+  for (auto _ : state)
+  {
+    benchmark::DoNotOptimize(exporter.Export(metrics));
+  }
+
+  state.SetItemsProcessed(state.iterations() * state.range(0));
+}
+
+BENCHMARK(BM_OtlpHttpMetricExporter_Export_Binary)
+    ->RangeMultiplier(10)
+    ->Range(1, 10000)
+    ->Unit(benchmark::kMicrosecond);
+
+BENCHMARK(BM_OtlpHttpMetricExporter_Export_Json)
+    ->RangeMultiplier(10)
+    ->Range(1, 10000)
+    ->Unit(benchmark::kMicrosecond);
+
+int main(int argc, char **argv)
+{
+  opentelemetry::sdk::common::internal_log::GlobalLogHandler::SetLogLevel(
+      opentelemetry::sdk::common::internal_log::LogLevel::None);
+
+  benchmark::Initialize(&argc, argv);
+  benchmark::RunSpecifiedBenchmarks();
+  benchmark::Shutdown();
+  return 0;
+}