OpenTelemetry C++ is an open-source observability framework for cloud-native software. It provides a collection of tools, APIs, and SDKs to instrument, generate, collect, and export telemetry data (metrics, logs, and traces) for analysis in order to understand your software's performance and behavior.

Pros

• Vendor-agnostic and compatible with various backends and analysis tools
• Supports multiple data types (traces, metrics, logs) for comprehensive observability
• Highly extensible and customizable to fit various use cases
• Part of the larger OpenTelemetry ecosystem, benefiting from community support and standardization

Cons

• Steeper learning curve compared to some simpler logging or metrics libraries
• Documentation can be complex for newcomers to distributed tracing and observability
• Still evolving, which may lead to occasional breaking changes or API adjustments
• Performance overhead, though minimal, needs to be considered for high-throughput systems

Code Examples

1. Creating a tracer and recording a span:

#include "opentelemetry/sdk/trace/simple_processor.h"
#include "opentelemetry/sdk/trace/tracer_provider.h"
#include "opentelemetry/trace/provider.h"

namespace trace = opentelemetry::trace;
namespace trace_sdk = opentelemetry::sdk::trace;

int main() {
    auto provider = trace_sdk::TracerProvider::Create();
    auto tracer = provider->GetTracer("example_tracer");

    auto span = tracer->StartSpan("MyOperation");
    // Perform your operation here
    span->End();

    return 0;
}

2. Adding attributes to a span:

auto span = tracer->StartSpan("MyOperation");
span->SetAttribute("http.method", "GET");
span->SetAttribute("http.url", "https://example.com");
span->End();

3. Creating a metric and recording measurements:

#include "opentelemetry/metrics/provider.h"
#include "opentelemetry/sdk/metrics/meter_provider.h"

namespace metrics = opentelemetry::metrics;
namespace metrics_sdk = opentelemetry::sdk::metrics;

int main() {
    auto provider = metrics_sdk::MeterProvider::Create();
    auto meter = provider->GetMeter("example_meter");

    auto counter = meter->CreateUInt64Counter("my_counter");
    counter->Add(1);

    return 0;
}

Getting Started

1. Install OpenTelemetry C++ using your preferred package manager or build from source.
2. Include the necessary headers in your project.
3. Initialize the OpenTelemetry SDK:

#include "opentelemetry/sdk/trace/simple_processor.h"
#include "opentelemetry/sdk/trace/tracer_provider.h"
#include "opentelemetry/trace/provider.h"

int main() {
    auto exporter = std::unique_ptr<sdktrace::SpanExporter>(new otlp::OtlpHttpExporter());
    auto processor = std::unique_ptr<sdktrace::SpanProcessor>(new sdktrace::SimpleSpanProcessor(std::move(exporter)));
    auto provider = nostd::shared_ptr<opentelemetry::trace::TracerProvider>(new sdktrace::TracerProvider(std::move(processor)));

    // Set the global trace provider
    opentelemetry::trace::Provider::SetTracerProvider(provider);

    // Use the tracer in your application
    auto tracer = opentelemetry::trace::Provider::GetTracerProvider()->GetTracer("my_library_name", "1.0.0");

    // Your application code here

    return 0;
}