Multiple Notifications Getting Delivered From GCM

Question

I am using PHP to send Notifications on multiple android devices at a time. All registration ids are unique, following is the CURL request that I am sending.

$url='https://android.googleapis.com/gcm/send'; $headers = array(                 'Authorization: key=' . ANDROID_KEY,                 'Content-Type: application/json'             ); $registration_ids = [];//with multiple registration ids $notification = array(                 'registration_ids' => $registration_ids,                 'data'             => array('notification_id' => $data['notification_id'],                                             'title'           => $data['title'],                                             'message'         => $data['message'])             ); $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, $url); curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); curl_setopt($ch, CURLOPT_FRESH_CONNECT, true); curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); curl_setopt($ch, CURLOPT_POST, true); curl_setopt($ch, CURLOPT_HTTPHEADER, $headers); curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($notification));            $res = curl_exec($ch); 

After debugging multiple times I could not find any reason for multiple notifications(more than 10 times) on the same device.

Is there any way to check the log of requests received by GCM. Any lead will be appreciated.

Answer 1

I figured the problem was with my android implementation. The device was getting registered multiple times.

GCM returns the same registration id for a device till the next reinstall. In some cases when the registration id gets expired/invalid GCM returns a new one.

At the time of pushing GCM will return the canonical registration id for expired/invalid token.

The solution is to read the response and update old registration id with the new one in the db.