I've filed an enhancement request for this: FB22267768

Our app needs to perform background video compression and upload, and this work can take around 30 minutes to 1 hour. The problem is that expirationHandler is called irregularly. Sometimes it seems related to task duration, and sometimes it seems related to system resources, but after many tests we still could not find a clear pattern.

Our app needs to perform background video compression and upload, and this work can take around 30 minutes to 1 hour. The problem is that expirationHandler is called irregularly. Sometimes it seems related to task duration, and sometimes it seems related to system resources, but after many tests we still could not find a clear pattern.

Our app needs to perform background video compression and upload, and this work can take around 30 minutes to 1 hour. The problem is that expirationHandler is called irregularly. Sometimes it seems related to task duration, and sometimes it seems related to system resources, but after many tests we still could not find a clear pattern.

Our app needs to perform background video compression and upload, and this work can take around 30 minutes to 1 hour. The problem is that expirationHandler is called irregularly. Sometimes it seems related to task duration, and sometimes it seems related to system resources, but after many tests we still could not find a clear pattern.