Do overlapping release dates matter for our mirrors?

[Matt Domsch]

On Wed, Nov 25, 2009 at 09:48:56AM -0800, John Poelstra wrote:
> 1) What is the minimum distance in days that we have to put between our 
> release and other distros?

The mirrors spike for about 2 days at the release of Ubuntu and
Fedora.

Ubuntu 9.10 released on Thursday, Oct 29.  Looking at the bandwidth
logs from mirrors.kernel.org, they spiked through Thursday, but by
Saturday were back to normal loads.

openSuSE 11.2 released on Thursday, Nov. 12.  They peaked on the 13th,
and were back to normal by the 15th.

Fedora 12 released on Tuesday, Nov. 17.  Due to DNS problems at
kernel.org, they didn't actually bitflip and start serving users until
late the 17th, but peaked and were back to normal by Saturday.

>From this, I'd argue that the minimum distance is 3 days, though both
the Ubuntu and Fedora have higher demand on these mirrors than
openSUSE (we could probably move closer to openSUSE if we had to).  5
days would be plenty.

 
> 2) Is it the release date that matters most or the date the staging starts?

It seems we can stage to our mirrors and have openSUSE release at the
same time without problem.  I doubt that's true of Ubuntu though - I
wouldn't want their release spike to coincide with our staging.

 
> 3) On a scale of 1 to 5 (1 = doesn't matter, 3 = moderate impact, 5 = 
> critical, we'd be out of our minds not to) how important is it that we 
> bend our schedule to not land as close as we might be potentially 
> landing with the dates below (assuming we do not slip)?

Depends who we collide with.  5 for ubuntu, 1 for anyone else.

Also, it's only a problem for mirrors carrying both.  I don't know how
many that is (MM doesn't track ubuntu URLs).  our Tier 1s certainly,
and maybe half of our Tier 2s.
 
> I'm really looking for a scale to get a sense of the severity and not 
> subjective responses like "it will be bad" or "people will hate us."  I 
> want to know "how much."
> 
> 4) Our current options as I understand them are:
>    a) Overlap closely (see below)
>    b) Add two weeks to Fedora 13
> 
>   Is there an "option C" that we could implement or go with so as not 
> to have to add two weeks to our scheduled GA date if the consensus score 
> from #3 is high?
> 
> ------------------------------------------------------
> 
> Debian                2010-March (Freeze, not an actual release date)
>
> Fedora 13             2010-04-27 (since Fedora 8 every release has been late >= 2 weeks)
> 
> Ubuntu 10.4           2010-04-29 (I'm told they have never slipped)
> 
> OpenSUSE              2010-05-05 (no idea on their "on time arrival history")

pull F13 in a week, or push 2 weeks.  Both falling the same week would
cause slower delivery to both our sets of end users.


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