OpenTelemetry Tracing

Enable distributed tracing for end-to-end visibility across your system.

Setting Up Tracing

use grpc_graphql_gateway::{Gateway, TracingConfig, init_tracer, shutdown_tracer};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Initialize the tracer
    let config = TracingConfig::new()
        .with_service_name("my-gateway")
        .with_sample_ratio(1.0);  // Sample all requests

    let _provider = init_tracer(&config);

    let gateway = Gateway::builder()
        .with_descriptor_set_bytes(DESCRIPTORS)
        .enable_tracing()
        .build()?;

    gateway.serve("0.0.0.0:8888").await?;

    // Shutdown on exit
    shutdown_tracer();
    Ok(())
}

Spans Created

Span Attributes

GraphQL Spans

gRPC Spans

OTLP Export

Enable OTLP export by adding the feature:

[dependencies]
grpc_graphql_gateway = { version = "0.2", features = ["otlp"] }

Then configure the exporter:

use grpc_graphql_gateway::TracingConfig;

let config = TracingConfig::new()
    .with_service_name("my-gateway")
    .with_otlp_endpoint("http://jaeger:4317");

Jaeger Integration

Run Jaeger locally:

docker run -d --name jaeger \
  -p 4317:4317 \
  -p 16686:16686 \
  jaegertracing/jaeger:1.47

View traces at: http://localhost:16686

Sampling Configuration

TracingConfig::new()
    .with_sample_ratio(0.1)  // 10% sampling

Context Propagation

The gateway automatically propagates trace context:

• Incoming HTTP headers (traceparent, tracestate)
• Outgoing gRPC metadata

Enable Header Propagation for distributed tracing headers.