Client retries

When to retry

Code	Retry?	Strategy
`2xx`	No (success)	—
`400`	No	Fix the body
`401`	No	Check the API key
`403`	No	Request the scope
`404`	No	Check the document key
`409`	No	Conflicting `Idempotency-Key`
`413`	No	Reduce the body
`429`	Yes	Respect `Retry-After`
`500`	Yes	Exponential backoff
`502`	Yes	Exponential backoff
`503`	Yes	Aggressive backoff (system down)
`504`	Yes	Exponential backoff
Client timeout	Yes	With `Idempotency-Key`

Exponential backoff algorithm with jitter


async function backoff(intento) {
  const base = Math.min(1000 * Math.pow(2, intento), 30000);  // max 30s
  const jitter = Math.random() * 1000;
  await sleep(base + jitter);
}
 
for (let i = 0; i < 5; i++) {
  try {
    return await llamarAPI();
  } catch (err) {
    if (esTransitorio(err) && i < 4) {
      await backoff(i);
      continue;
    }
    throw err;
  }
}