Last days there were problems with repo.zabbix.com. Some unofficial mirrors appeared https://github.com/monitoringartist/repo.zabbix.com but this requires explicit change in sources.list.
Instead, we could use the same method as http://httpredir.debian.org/ (I use it since very begginging and I'm happy with the solution), which ensures up to date and only working backends, provides load balancing.
People interested in running mirror (and there are some, including myself) would need some information/stats:
1. How much disk space does current mirror use? If partial mirrors are OK, it would be nice to provide information about space needed by deb repo only, rpm repo only, sources. Or only by current (newest stable) version.
2. How much traffic does repo need? Monthly transfer or typical bandwidth used should be OK. Of course mirrors in distributed repo will receive less traffic, but in pessimistic scenario each might be hit by full traffic.
3. Official recommendations how to create mirror and info how to join the project would be nice. There are descriptions for creating Debian mirrors, but there might be some changes and recommendations regarding frequency of updates.