Creating manual spans with OpenTelemetry for non-auto-instrumented code

Auto-instrumentation covers HTTP, DB, and framework calls but misses custom business logic, background jobs, and third-party SDKs. These operations are invisible in traces, making it impossible to see where time is spent inside your application code.

Use the OpenTelemetry API tracer to manually create spans around important operations. Always end spans in a finally block to ensure they close even on error.

const { trace, SpanStatusCode } = require('@opentelemetry/api');

const tracer = trace.getTracer('my-service', '1.0.0');

async function processOrder(orderId) {
  return tracer.startActiveSpan('processOrder', async (span) => {
    span.setAttribute('order.id', orderId);
    try {
      const result = await doWork(orderId);
      span.setStatus({ code: SpanStatusCode.OK });
      return result;
    } catch (err) {
      span.recordException(err);
      span.setStatus({ code: SpanStatusCode.ERROR, message: err.message });
      throw err;
    } finally {
      span.end();
    }
  });
}

startActiveSpan automatically sets the new span as the active span in the current context, so any child spans created inside the callback will be correctly parented without manual context propagation.

Adding observability to custom business logic or third-party library calls