Comment 4 for bug 1609524

Long term, as your deployment grows you probably want to switch to using fernet tokens as they are not persisted, you won't need to run that cron job at all. But doing this increases the complexity of running keystone, so let's put that aside for now.

Have you tried simply reducing the frequency of the cron job? How many users are able to access the cloud? Running once per hour for 20 instances seems unnecessarily aggressive.