Unable to upload multiple files to Google drive using PHP SDK - google-app-engine

Question

I am trying to upload multiple files to Google drive using the PHP SDK. For this I am calling the function below iteratively passing the required parameters:
function insertFile($driveService, $title, $description, $parentId, $fileUrl) {
global $header;
$file = new Google_DriveFile();
$file->setTitle($title);
$file->setDescription($description);
$mimeType= "application/vnd.google-apps.folder";
if ($fileUrl != null) {
$fileUrl = replaceSpaceWithHtmlCode($fileUrl);
$header = getUrlHeader($fileUrl);
$mimeType = $header['content-type'];
}
$file->setMimeType($mimeType);
$parent = new Google_ParentReference();
// Set the parent folder.
if ($parentId != null) {
$parent->setId($parentId);
$file->setParents(array($parent));
}
try {
$data = null;
if ($fileUrl != null) {
if (hasErrors($driveService, $fileUrl) == True) {
return null;
}
$data = file_get_contents($fileUrl);
}
$createdFile = $driveService->files->insert($file, array(
'data' => $data,
'mimeType' => $mimeType,
));
return $createdFile;
} catch (Exception $e) {
echo "Error: 12";
return null;
}
}
I am running this app on the Google App Engine.
However, I am unable to upload all the files I pass to it. For example, if I pass about 12-15 files, only 10-11 get uploaded, and sometimes all get uploaded, even though all parameters are correct. I have caught the exception when it fails to create a file and this says it is unable to create a file, for the files that are not uploaded. I don't see any warnings or errors in the logs on the app engine.
Am I missing something? Can someone please point me where I should be looking to correct this and make it reliable enough to upload all files given to it?
The HTTP response that I get when I try to upload 30 files is this:
PHP Fatal error: The request was aborted because it exceeded the maximum execution time

Answer 1

Check the http response to see the detailed reason. It might be that you are hitting the throttle limit and getting a 403 rate limit response.