We are currently testing the implementation of our Location Push Service Extension (LPSE) in both Ad Hoc and Release environments. We have encountered an issue where LPSE notifications, which were previously working correctly, suddenly fail to be delivered on some devices. After a period of several hours, the notifications resume arriving, but the issue remains intermittent. Notably, during these periods of suspected delivery restriction, regular push notifications (e.g., those using apns-push-type: alert) are delivered and displayed without any problem.
[Detailed Situation]
- Test Environment and Scope
We are testing LPSE after obtaining the necessary entitlements, in both Ad Hoc and Release environments. The issue is not observed on all test devices; only certain devices are affected.
- Observed Behavior
Under normal circumstances, LPSE notifications are received and the extension is activated; however, on some devices the notifications suddenly stop arriving. During these periods, even when sending notifications with apns-push-type: location directly via the CloudKit Push Notification Console, no response is observed on the affected devices. The APNs server (api.push.apple.com) always returns a 200 OK response via HTTP/2, and our server-side logs and configurations (DNS resolution performed on every request, using the same JWT token for 59 minutes per session, communication via HTTP/2 with ALPN Protocol: h2) show no issues. Other app functionalities (network communication, UI responsiveness, etc.) work normally.
- Sending content
When sending notifications from our server to APNs (api.push.apple.com), we use the following configuration (over HTTP/2):
const payload = {
aps: { 'content-available': 1 }
};
const headers = {
':method': 'POST',
':path': /3/device/${apnsToken},
'Authorization': bearer ${jwtToken},
'apns-topic': 'ot.Here.location-query',
'apns-priority': '10',
'apns-push-type': 'location',
'Content-Type': 'application/json'
};
We perform DNS resolution for every request, use the same JWT token for a 59-minute period per session, and communicate via HTTP/2 with ALPN Protocol: h2.
- Hypothesis on the Cause
We suspect that due to an implementation issue, silent push notifications (using content-available: 1) were being sent every few minutes concurrently, which may have triggered an APNs delivery restriction (rate limiting). As a countermeasure, we have completely stopped sending silent pushes and any other background notifications aside from LPSE; however, the issue persists. Additionally, even after resetting affected devices, the delivery problem continues to occur.
[Questions for Diagnosis]
-
Given the above situation, is it reasonable to suspect that excessive silent push notifications have triggered an APNs delivery restriction?
-
Does such a silent push restriction affect LPSE notifications (i.e., those sent with apns-push-type: location)?
-
Do APNs delivery restrictions persist even after a device has been reset?
-
Can a high volume of LPSE notifications alone (without silent pushes) also trigger a delivery restriction?
→ This is our primary concern since it poses a significant implementation challenge.
Please let us know if any additional information is required for diagnosis.
