node_span_start.js

node_span_start.js

app.get('/hello', (req, res) => {
  // start a new span named “sleeper”
 const childSpan = tracer.startSpan("sleeper");

 setTimeout(()=> {
   // childSpan works normally when referenced
   childSpan.addEvent('finished sleeping');
   // However, starting a span does not automatically
   // set it to the current span. getCurrentSpan still 
   // returns the parent span.
   tracer.getCurrentSpan();
   res.status(200).send('Hello World');
   // Ending the span is a requirement. It measures the duration 
   // of the operation, and then sends the span to the exporter.
   childSpan.end();
 }, 300);
});