Hello,
I checked our logs and noticed that some of the web pages converted by your application take too long to load (more than 3 minutes). I don't know how your application is implement but it seems that this increases the probability that your application will send multiple requests at a time.
I would recommend the following steps to resolve the issue.
1/ Ensure that your web pages load in a timely fashion. Consider caching a web page first and then call the API with a warm cache.
2/ If the API returns the 503 error (Simultaneous API calls from a single IP are not allowed), it is perfectly OK to sleep for a few seconds and then resend the unsuccessful request.
$tries = 0;
$success = false;
while (!$success) {
$tries += 1;
try {
// call the API
$success = true;
} catch(PdfcrowdException $why) {
if ($why->getCode() != 503 || $tries == 5) {
// log error and re-throw the exception
throw $why;
} else {
sleep(1);
}
}
}