Facebook Graph Api error "An unexpected error has occurred. Please retry your request later" - facebook

Question

I'm trying to retrieve all members in a Facebook group getting this error:
array(5) {
["message"]=>
string(66) "An unexpected error has occurred. Please retry your request later."
["type"]=>
string(14) "OAuthException"
["is_transient"]=>
bool(true)
["code"]=>
int(2)
["fbtrace_id"]=>
string(11) "AnfsXcdgM"
}
Here is my code:
$this->_facebook = new Facebook\Facebook(array('app_id' => "$app_id",'app_secret' => "$secret",'default_graph_version' => 'v2.10'));
$this->_facebook->setDefaultAccessToken($_SESSION['facebook_access_token']);
$query = "/".$groupID."/members?fields=id,name,link,picture,first_name,last_name";
try{
$response = $this->_facebook->get($query);
while($pagesEdge)
{
$pageDecoded = json_decode($pagesEdge);
foreach($pageDecoded as $key => $member)
{
$id = $member->id;
}
}
}catch (Facebook\Exceptions\FacebookResponseException $e) { echo 'Graph returned an error: ' . $e->getMessage(); }
It works for groups with few hundreads of people (even once for a group with 10.000 members) but randomly I'm occurring to this.

Answer 1

This might be caused by a server side timeout. I get this error every now and then when I request a huge amount of data. Maybe you should try to limit your request by using the limit parameter (default should be 25).

Answer 2

I solved this by doing a cron that takes 100 data at the time and putting into a file text the value of the token for the next call.
I add this string on the query and when the fields inside $url are empty I quit my execution
<?php
public function updateGroupMembers($groupID)
{
$tempNext = file_get_contents($this->dirM); //check if the next string token is in the file
if (!empty($tempNext))
{
$queryUntil = $tempNext;
}
// Sets the default fallback access token so we don't have to pass it to each request
$this->_facebook->setDefaultAccessToken($_SESSION['facebook_access_token']);
// Create table name
$tableName = $groupID . "_Members";
// Query the Graph API to get all current member's ID and name
try
{
$query = "/".$groupID."/members?fields=id,name,link,picture,first_name,last_name".$queryUntil; //add the next string to my query
$response = $this->_facebook->get($query);
$pagesEdge = $response->getGraphEdge();
// Index for the elements fetched from the API below
$i = 0;
// Get current time
$pageDecoded = json_decode($pagesEdge);
foreach($pageDecoded as $key => $member)
{
/* ...get data and process them... */
}
$temp = $pagesEdge->getMetaData();
$next = parse_url($temp['paging']['next']);
parse_str($next['query'], $url);
$access_token = '&access_token='.$url['access_token'];
$fields = '&fields='.$url['fields'];
$limit = '&limit=100';
$after = '&after='.$url['after'];
$res['until'] = $access_token.$fields.$limit.$after;
file_put_contents($this->dirM, $res['until'], LOCK_EX);
if ( empty($url['access_token']) || empty($url['fields']) || empty($url['limit']) || empty($url['after']) )
{
file_put_contents($this->dirM, '', LOCK_EX); //clean my txt file that contains my next string
die('FINE');
}
} catch (Facebook\Exceptions\FacebookResponseException $e) {
echo 'm2Graph returned an error: ' . $e->getMessage();
exit;
} catch (Facebook\Exceptions\FacebookSDKException $e) {
echo 'm2Facebook SDK returned an error: ' . $e->getMessage();
exit;
}
}