Bit flip

[Matt Domsch]

On Tue, Apr 28, 2009 at 10:34:51AM -0500, Matt Domsch wrote:
> Backwards math:
> 
> Time to generate and publish updated mirrorlist: 20 minutes
> Time to crawl all mirrors: ~2 hours
> Time for most mirrors to rsync and catch the bitflip: 6 hours

Insert step: Time for update-master-directory-list to catch the
bitflip: 30 minutes

> Time to sync bitflip to all three netapps: < 30 minutes (maybe <<).
> Time to do bitflip: 1 minute

Shortest time through the path is: 1+30+30+120+20, or nearly 3.5
hours, which lines up well with Mike's observation that 3.5 hours was
needed before we stopped sending people to closed mirrors.

So, I'd like to propose we back up the bitflip by at least 4 hours
from release time, perhaps as much as 6.

I'd also like to move the update-mirrorlist cronjob back to start at
:40 past the hour, so content is in place by :00.

-- 
Matt Domsch
Linux Technology Strategist, Dell Office of the CTO
linux.dell.com & www.dell.com/linux