Exporters

In order to visualize and analyze your traces and metrics, you will need to export them to a backend.

Trace exporters

OStream exporter

The OStream exporter is useful for development and debugging tasks, and is the simplest to set up.

auto ostream_exporter =
    std::unique_ptr<opentelemetry::sdk::trace::SpanExporter>(new opentelemetry::exporter::trace::OStreamSpanExporter);

OTLP endpoint

To send trace data to an OTLP endpoint (like the collector or Jaeger) you’ll want to configure an OTLP exporter that sends to your endpoint.

OTLP HTTP Exporter

opentelemetry::exporter::otlp::OtlpHttpExporterOptions opts;
opts.url = "http://localhost:4318/v1/traces";
auto otlp_http_exporter =
    std::unique_ptr<opentelemetry::sdk::trace::SpanExporter>(new opentelemetry::exporter::otlp::OtlpHttpExporter(opts));

OTLP GRPC Exporter

opentelemetry::exporter::otlp::OtlpGrpcExporterOptions opts;
opts.endpoint = "localhost:4317";
opts.use_ssl_credentials = true;
opts.ssl_credentials_cacert_as_string = "ssl-certificate";
auto otlp_grpc_exporter =
    std::unique_ptr<opentelemetry::sdk::trace::SpanExporter>(new opentelemetry::exporter::otlp::OtlpGrpcExporter(opts));

You can find an example of how to use the OTLP exporter here.

Jaeger

To try out the OTLP exporter, you can run Jaeger as an OTLP endpoint and for trace visualization in a docker container:

docker run -d --name jaeger \
  -e COLLECTOR_ZIPKIN_HOST_PORT=:9411 \
  -e COLLECTOR_OTLP_ENABLED=true \
  -p 6831:6831/udp \
  -p 6832:6832/udp \
  -p 5778:5778 \
  -p 16686:16686 \
  -p 4317:4317 \
  -p 4318:4318 \
  -p 14250:14250 \
  -p 14268:14268 \
  -p 14269:14269 \
  -p 9411:9411 \
  jaegertracing/all-in-one:latest

Zipkin

To send trace data to a zipkin endpoint you’ll want to configure a zipkin exporter that sends to your endpoint.

opentelemetry::exporter::zipkin::ZipkinExporterOptions opts;
opts.endpoint = "http://localhost:9411/api/v2/spans" ; // or export OTEL_EXPORTER_ZIPKIN_ENDPOINT="..."
opts.service_name = "default_service" ;
auto zipkin_exporter =
    std::unique_ptr<opentelemetry::sdk::trace::SpanExporter>(new opentelemetry::exporter::zipkin::ZipkinExporter(opts));

Metrics exporters

OTLP HTTP Exporter

opentelemetry::exporter::otlp::OtlpHttpExporterOptions otlpOptions;
otlpOptions.url = "http://localhost:4318/v1/metrics"; // or "http://localhost:4318/
otlpOptions.aggregation_temporality = opentelemetry::sdk::metrics::AggregationTemporality::kCumulative; // or kDelta
auto exporter = opentelemetry::exporter::otlp::OtlpHttpMetricExporterFactory::Create(otlpOptions);
// Initialize and set the periodic metrics reader
opentelemetry::sdk::metrics::PeriodicExportingMetricReaderOptions options;
options.export_interval_millis = std::chrono::milliseconds(1000);
options.export_timeout_millis  = std::chrono::milliseconds(500);
std::unique_ptr<opentelemetry::sdk::metrics::MetricReader> reader{
    new opentelemetry::sdk::metrics::PeriodicExportingMetricReader(std::move(exporter), options)};

OTLP gRPC Exporter

opentelemetry::exporter::otlp::OtlpGrpcMetricExporterOptions otlpOptions;
otlpOptions.endpoint = "localhost:4317/v1/metrics";  // or "localhost:4317
otlpOptions.aggregation_temporality = opentelemetry::sdk::metrics::AggregationTemporality::kDelta; // or kCumulative
auto exporter = opentelemetry::exporter::otlp::OtlpGrpcMetricExporterFactory::Create(otlpOptions);
// Initialize and set the periodic metrics reader
opentelemetry::sdk::metrics::PeriodicExportingMetricReaderOptions options;
options.export_interval_millis = std::chrono::milliseconds(1000);
options.export_timeout_millis  = std::chrono::milliseconds(500);
std::unique_ptr<opentelemetry::sdk::metrics::MetricReader> reader{
    new opentelemetry::sdk::metrics::PeriodicExportingMetricReader(std::move(exporter), options)};

Prometheus

To send metrics to a prometheus endpoint you’ll want to configure a prometheus exporter

opentelemetry::sdk::metrics::PeriodicExportingMetricReaderOptions options;
options.export_interval_millis = std::chrono::milliseconds(1000); //optional, to override default values
options.export_timeout_millis  = std::chrono::milliseconds(500); // optional, to override default values
opentelemetry::exporter::metrics::PrometheusExporterOptions prometheusOptions;
prometheusOptions.url = "localhost:8080";
std::unique_ptr<opentelemetry::sdk::metrics::MetricExporter> exporter{new opentelemetry::exporter::metrics::PrometheusExporter(prometheusOptions)};
std::unique_ptr<opentelemetry::sdk::metrics::MetricReader> reader{
    new opentelemetry::sdk::metrics::PeriodicExportingMetricReader(std::move(exporter), options)};

To learn more on how to use the Prometheus exporter, try out the prometheus example

Next steps

Enriching your codebase with manual instrumentation gives you customized observability data.