New Server?

[Gerald Combs]

Jonathan Hutchins wrote:
> So how about a status report, or better yet a juicy saga, of the new KCLUG.ORG 
> server?
> 
> NetStandard is still pointing to Illiana for our IP, so we haven't achieved 
> cutover.  What's the tentative schedule?
> 
> Are we just going to update the DNS record and let it propagate, or can we do 
> something at illiana like set a forwarding address so that all the mail makes 
> the switch at once and they don't have to run in parallel while the DNS 
> update propagates?  
> 
> If I recall correctly, at least one of our posters is in South America 
> somewhere, so he would probably be the maximum lag on the DNS.  Or not, 
> geography doesn't always determine.

The TTL for kclug.org's MX record is 30 minutes:

----
bam:/home/gerald> host -vt mx kclug.org
Trying "kclug.org"

  [ ... ]

kclug.org.              1800    IN      MX      10 marauder.illiana.net.

  [ ... ]

----

Theoretically, all mail should start going to the new server within 30
minutes of the switch as any MX entries that may have been hanging
around expire from various DNS server caches.  If you don't have the
record cached the change should be instantaneous.  In reality, some DNS
and mail products are Just Plain Dumb and hold on to entries far longer
than they should.  This problem isn't affected by geography.

A couple of things can be done to mitigate the issue.  The TTL can be
tuned down to a small value (e.g. 30 seconds) before the move, so that
the cache window is small.  The mail server at illiana.net can be
configured to forward all kclug mail to the new server.  Given the
[in]frequency of posts to the lists, I'm not sure it's worth worrying
about, however.