By default @upstash/redis will retry sending you request when network errors occur. It will retry 5 times with a backoff of (retryCount) => Math.exp(retryCount) * 50 milliseconds. You can customize this in the Redis constructor:
new Redis({
  url: UPSTASH_REDIS_REST_URL,
  token: UPSTASH_REDIS_REST_TOKEN,
  retry: {
    retries: 5,
    backoff: (retryCount) => Math.exp(retryCount) * 50,
  },
});
The exact type definition can be found here.