[CentOS-mirror] How often to synchronize mirror?

Dear All,

I run public mirror (bay.uchicago.edu), and today I have noticed that the status page

https://mirror-status.centos.org/

shows in red it is not in sync for 5 hours, or so. It's been quite some time ago when I first installed it, and that time decent practice was to sync 3 times a day (about once every eight hours). More often was assumed to overwhelm higher tier source.

What is good practice these days: how often it is OK to synchronize mirror? I changed sync to every other hour (once I notices it shining red on mirror status page). Is that OK, or that will overwhelm higher tier mirror?

Thanks a lot for your advises!

Valeri