[CentOS-mirror] New CentOS Mirror

Sun Jun 16 08:19:59 UTC 2019
Anssi Johansson <avij at centosproject.org>

James kirjoitti 16.6.2019 klo 10.35:
> Is information such as bandwidth and sync schedule stored internally to 
> be used in any purposeful manner (ie. prioritizing or load balancing the 
> mirror list)?
> 
> Reason I'm asking is that if the bandwidth or sync schedule is ever 
> upgraded or changed, is it necessary to inform the centos-mirror list?

At the moment we ask these primarily to make sure the mirror has 
sufficient bandwidth to be accepted, and also to make sure the mirror's 
sync frequency is reasonable.

We do use the bandwidth information in one situation -- if the country 
of the client requesting a list of mirrors from mirrorlist.centos.org 
can't be determined, we pick a random mirror from each continent and 
then a few more random mirrors from all over the world to reach the 
required 10 mirrors. A requirement for these "fallback" mirrors is that 
they have >= 200 Mbps of bandwidth [1]. In the past we had a static list 
of fallback mirrors, but we switched to a more dynamic method last year.

Apart from that, we don't currently use the bandwidth information for 
load balancing purposes, but we're collecting that information into our 
database in case we some day end up changing our mirrorlist code to 
prefer mirrors with more bandwidth. If this ever happens, it's likely 
that we'll post a notice on the list and ask mirror admins to make sure 
our bandwidth information is up-to-date. Before that happens I would not 
worry about this too much.

As for sync schedules, as long as you keep your sync schedules within 
sane limits, you don't need to inform the list. What constitutes a "sane 
limit" is a matter of opinion, but when I'm asked about this, I usually 
recommend [2] either every 6 hours or every 4 hours, depending on 
mirror's preferences. The acceptable range is every 1-12 hours. We don't 
record the sync frequency in our database.


[1] 
https://github.com/CentOS/mirrorlists-code/blob/master/backend/makemirrorlists-combined.pl#L315
[2] https://lists.centos.org/pipermail/centos-mirror/2019-June/011713.html