Files API and Google Cloud storage

[Arne]

I am building a system that  needs to save files from Google App Engine's blobstore to Google Cloud Storage. It works fine for small files (<40 mb) but for larger files it get gets unstable and GAE throws and FileNotOpenedError. To my understanding the reason for this is as described in  GAE Issue 5371 that the Files API closes the file every 30 seconds. To my knowledge there are no way to work around this because it is not possible to re-open av file for writing in Google Cloud Storage. 

When I first become aware of this issue 6 month ago and asked about it on Stackoverflow and  the unstability started at around 10 mb. It have improved since that but since this all is undocumented I do not know if that is just due to the servers being in better mood this month. I order for me to build something reliable I need to know more about what this API is built to handle. Do anybody have some insight to share?

best

Arne