Latest revision as of 12:12, 30 August 2012

[edit] 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)

[edit] 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.

[edit] 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.

[edit] Tier 1 Mirrors

Tier 1 mirrors pull from one of the master mirrors.

[edit] 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) ...