C++ Opentelemetry Instrumentation
This document contains instructions on how to set up OpenTelemetry instrumentation in your C++ applications and view your application traces in SigNoz.
Requirements
Send Traces to SigNoz
Based on your application environment, you can choose the setup below to send traces to SigNoz.
Send traces to SigNoz Cloud via OTel Collector binary
Step 1 : Install OTel Collector
OTel Collector binary helps to collect logs, hostmetrics, resource and infra attributes. You can find instructions to install OTel Collector binary here in your VM.
Step 2 : Build opentelemetry-cpp locally
To configure your C++ application to send traces to OpenTelemetry you need to install opentelemetry-cpp and add it as dependency in your project.
Build opentelemetry-cpp locally using Bezel, following these steps:
- Clone the
opentelemetry-cppsource code.
git clone https://github.com/open-telemetry/opentelemetry-cpp.git
- Navigate to the repository cloned above, download the dependencies and build the source code:
cd opentelemetry-cpp
bazel build //...
- Once Bazel tests are built, run them with
bazel test //...command
bazel test //...
Step 3 : Instrument your application with OpenTelemetry
Add the following to BUILD file:
cc_binary(
name = "<name>",
srcs = [
"<file_name>.cc",
],
tags = [
"examples",
"otlp",
"otlp_http",
],
deps = [
"//api",
"//exporters/otlp:otlp_http_exporter",
"//sdk/src/trace",
],
)
Add the following content to main.cpp:
#include <memory>
#include <string>
#include <utility>
#include "opentelemetry/exporters/otlp/otlp_environment.h"
#include "opentelemetry/exporters/otlp/otlp_http.h"
#include "opentelemetry/exporters/otlp/otlp_http_exporter_factory.h"
#include "opentelemetry/exporters/otlp/otlp_http_exporter_options.h"
#include "opentelemetry/sdk/common/global_log_handler.h"
#include "opentelemetry/sdk/trace/processor.h"
#include "opentelemetry/sdk/trace/recordable.h"
#include "opentelemetry/sdk/trace/simple_processor_factory.h"
#include "opentelemetry/sdk/trace/tracer_provider.h"
#include "opentelemetry/sdk/trace/tracer_provider_factory.h"
#include "opentelemetry/trace/provider.h"
#include "opentelemetry/trace/span_id.h"
#include "opentelemetry/trace/tracer_provider.h"
namespace trace = opentelemetry::trace;
namespace trace_sdk = opentelemetry::sdk::trace;
namespace otlp = opentelemetry::exporter::otlp;
namespace internal_log = opentelemetry::sdk::common::internal_log;
namespace
{
opentelemetry::exporter::otlp::OtlpHttpExporterOptions opts;
std::shared_ptr<opentelemetry::sdk::trace::TracerProvider> provider;
void InitTracer()
{
auto exporter = otlp::OtlpHttpExporterFactory::Create(opts);
auto processor = trace_sdk::SimpleSpanProcessorFactory::Create(std::move(exporter));
provider = trace_sdk::TracerProviderFactory::Create(std::move(processor));
std::shared_ptr<opentelemetry::trace::TracerProvider> api_provider = provider;
trace::Provider::SetTracerProvider(api_provider);
}
void CleanupTracer()
{
// We call ForceFlush to prevent to cancel running exportings, It's optional.
if (provider)
{
provider->ForceFlush();
}
provider.reset();
std::shared_ptr<opentelemetry::trace::TracerProvider> none;
trace::Provider::SetTracerProvider(none);
}
} // namespace
int main()
{
InitTracer();
foo_library();
CleanupTracer();
}
This code sets up OpenTelemetry tracing in your C++ application, initializes a tracer with an OTLP HTTP exporter, processes spans, and sends trace data to a SigNoz.
Step 4: Run app
Execute your application by issuing the run command:
bazel run <name>
<name> refers to the name of the binary target for your application, which you define in the BUILD file.
