[Koha-devel] Relocating koha.org services

[Dobrica Pavlinusic]

On Fri, Apr 09, 2010 at 12:36:10PM -0700, Clay Fouts wrote:
> Hi, all.
> 
> With the shift of koha.org-related services from Metavore (LibLime's former
> owner) to PTFS, we're going to be relocating a few of the services that
> currently reside on Metavore assets. Most notably, wiki.koha.org and
> git.koha.org are going to move to a new system. This will involve a bit of
> semi-downtime for each due to DNS propagation.
> 
> It's undesirable and unnecessary to lose read access to these services; I'll
> copy the data to the new location, redefine the DNS entries, and convergence
> can take its sweet time. However, in order to minimize data syncronization
> issues, I'm requesting that no changes be made to either of them after
> 2010-04-12 07:00 UTC. I'll complete the transfer sometime during the 24-hr
> period after that. Once DNS convergence is complete (theoretically only two
> hours, but waiting 12 will be safer), I'll shut down the old service
> locations and it will be safe to resume changes. I'll send another
> announcement when that window has passed.

Just my $0.02:

In the past I had to setup various failover systems, so I usually use very
low ttl (2 sec or so) in DNS entries (wiki.koha.org and git.koha.org) before
migration (it seems that current ttl is 7200 seconds, so at least two hours
before migration) and after switch make mod_rewrite proxy rule on old server
which would proxy all requests to new one (using IP adress for obvious
reasons) until everthing in DNS expires.

Another alternative might be to add wiki2 and git2 aliases to new IP
adress and issue 302 Location redirects on old server until DNS expires.

Hopefully, this might help transitions smoother in future.

-- 
Dobrica Pavlinusic               2share!2flame            dpavlin at rot13.org
Unix addict. Internet consultant.             http://www.rot13.org/~dpavlin