const tracer = trace.getTracer('payment');
const meter = metrics.getMeter('payment');
const transactionsCounter = meter.createCounter('demo.payment.transactions', {
  unit: '{transaction}',
});
…
module.exports.charge = async request => {
  const span = tracer.startSpan('charge');

  try {
    …
    const card = cardValidator(number);
    const { card_type: cardType, valid } = card.getCardDetails();

    const loyalty_level = random(LOYALTY_LEVEL);

    span.setAttributes({
      'demo.payment.card_type': cardType,
      'demo.payment.card_valid': valid,
      'demo.user_context.loyalty_level': loyalty_level,
      ...(emitRawPii && {
        'demo.payment.card_number': number,
        'demo.payment.card_cvv': cvv
      })
    });

    if (!valid) {
      throw new Error('Credit card info is invalid.');
    }
    …
    const { units, nanos, currencyCode } = request.amount;
    logger.info({ transactionId, cardType, lastFourDigits, amount: { units, nanos, currencyCode }, loyalty_level }, 'Transaction complete.');
    transactionsCounter.add(1, { 'demo.payment.currency': currencyCode });

    return { transactionId };
  } catch (err) {
    span.recordException(err);
    span.setStatus({ code: SpanStatusCode.ERROR, message: err.message });
    span.setAttribute(ATTR_ERROR_TYPE, err.name || 'Error');

    throw err;
  } finally {
    span.end();
  }
};

Warm-up