Infrastructure/Mirroring/Tiering

Tiering

Fedora mirror servers use Tiering, whereby a select few fast mirrors get read access to the master rsync servers, and all the other mirrors pull from those mirrors.

It turns out, 9 of our 10 Tier 1 mirrors are available over Internet2. And, over half of our total mirrors are reachable over Internet2. So, let's make use of that whereever we can.

For our purposes, define:

• master: The Fedora-owned servers dl.fedoraproject.org and download-i2.fedoraproject.org
• Tier 1: The fast mirrors which pull from a master mirror.
• Tier 2: The mirrors that pull from the Tier 1 servers.

Properties of Tier 1 mirrors:

• Limit the number of Tier 1 mirrors, to ensure adequate bandwidth for these. Adjust number up or down depending on capability of the masters.
• Must carry everything under fedora-enchilada and fedora-epel. This allows Tier 2 mirrors to exclude what they wish, but get everything if they so wish. This means at least 1TB of disk space for the Fedora portion of this server.
• Must have a 1 Gigabit connection to the Internet, or faster.
• Must have an active, available, responsive mirror administrator during the days content is staged.
• Must have at least 2 Internet2-connected Tier 1 mirrors.
• Must have at least 1 Tier 1 mirror on each continent for which we have Tier 2 mirrors
• Must serve private rsync (see below for configuration)

Master Mirrors

• dl0[12345].fedoraproject.org, in Phoenix, AZ, USA.
  • dl.fedoraproject.org is a DNS round-robin to dl0[12345].
• download-i2.fedoraproject.org in Raleigh, NC, USA (Internet2, NLR, and those reachable over NLR only) This is the preferred master mirror for downstreams reachable on Internet2.

Master Mirror rsync modules

The master mirrors provide two additional rsync modules which provide pre-bitflip content. Fedora tiered mirrors should use these modules to be able to get pre-bitflip content.

module name	content
fedora-enchilada0	Everything under /pub/fedora/, including pre-bitflip content
fedora-epel0	Everything under /pub/epel, including pre-bitflip content (even though EPEL doesn't do bitflips

Tier 1 Mirrors

Tier 1 mirrors pull from one of the master mirrors.

Server	Comment	Contact for ACL
fedora-archives.ibiblio.org	Internet2 / National Lamba Rail (NLR) connected hosts.	<fedora-admin@ibiblio.org> No ACLs - open for syncing.
archive.linux.duke.edu	Internet2. Uses ACL from MirrorManager database.	Drew Stinnett <drew.stinnett at duke.edu> (spacepope on IRC)
kernel.org	mirrors1.kernel.org, mirrors2.kernel.org - USx2, mirrors3.kernel.org - NL, mirrors4.kernel.org - SE Do not sync from mirrors.kernel.org, choose one of the ones above and use that.	<ftpadmin at kernel.org>
wpi.edu	IPv6-connected or Internet2-connected mirrors only	Chuck Anderson <cra at wpi.edu>
rsync.hrz.tu-chemnitz.de	rsync.hrz.tu-chemnitz.de::fedora-enchilada/. Uses ACL from MirrorManager database .	guenther.fischer at hrz.tu-chemnitz.de
fedora-rsync.ftp.pub.2iij.net	rsync://fedora-rsync.ftp.pub.2iij.net/fedora-enchilada	mirror-contact at iij.ad.jp
sunsite.mff.cuni.cz
ftp.heanet.ie	IPv6 and Internet2 connectivity. ftp.heanet.ie::fedora-enchilada, ftp.heanet.ie::fedora-epel	mirrors at heanet.ie
mirror.speedpartner.de	IPv4 and IPv6	mirror at speedpartner.de
fedora.c3sl.ufpr.br	South America	Carlos Carvalho carlos at fisica.ufpr.br
ftp.linux.cz	Czech Republic, Europe	ftp-admin at fi.muni.cz
mirror.gtlib.gatech.edu	fedora-enchilada and fedora-epel	Neil Bright neil.bright at oit.gatech.edu
mirrors.rit.edu	Rochester, NY, USA	mirrors@rit.edu

Tier 1 Rsync configuration

Below is an example rsyncd.conf file for a Tier 1 mirror that provides private rsync access to select downstream Tier 2 mirrors. You may do this via either IP or DNS-based access control, or by a shared username/password which you give to your selected Tier 2 mirrors directly.

The key to this is that the Tier 1 mirror rsyncs content using a user account (e.g. mirror used below), and you serve content to Tier 2 mirrors using a private rsync module that runs as that same user account, while providing public non-authenticated rsync using the nobody account. In this way, Tier 2 mirrors may obtain content before the permissions are made world readable.

use chroot = yes
uid = nobody
gid = nobody
dont compress = *.gz *.tgz *.zip *.z *.rpm *.deb *.bz2 *.iso *.ogg *.ogv *.tbz
exclude = .snapshot/ .~tmp~/ /.private/ /.private/** **/.nfs*
ignore nonreadable = yes
list = true
read only = yes
refuse options = checksum

[ fedora-enchilada ]
        comment = Fedora - The whole enchilada
        path = /srv/pub/fedora

[ fedora-epel ]
        comment = Extra Packages for Enterprise Linux
        path = /srv/pub/epel

##
## The following are not seen and are limited by IP.
##

[fedora-enchilada0]
       comment = Fedora Enchilada for Tier0|1 Mirrors
       path = /srv/pub/fedora/
       list = no
       uid = mirror
       gid = mirror
       hosts allow = (IP or DNS address) ...

[fedora-epel0]
       comment = Fedora EPEL for Tier0|1 Mirrors
       path = /srv/pub/epel/
       list = no
       uid = mirror
       gid = mirror
       hosts allow = (IP or DNS address) ...