I think that the database server should have it's IP changed to 130.94.122.199 (That's what the new server is currently using). We can then change the new server to use the current wiki IP.
This way, the upgrade is complete and immediate, and we don't have DNS issues, which we know can be more pain than they're worth.
Of course, there is the one scary question: "What if they don't come up with the right IP's and we can't do anything about it?". That would be bad, but I don't think it would be a problem if we just changed the IP's in /etc/sysconfig/network-scripts/ifcfg-eth0, and did a reboot when we were ready.
Either way, I'll try to set the TTL to a low value.
Jason
Of, course, we can do whatever. I just think that this will be the least painful for everyone involved.
Lee Daniel Crocker wrote:
The new server is up and has all the software installed on it, so now we need to come up with a plan for moving the systems to the new setup.
It will /almost/ be possible to do it cleanly with DNS without anyone noticing--just bring apache up on the new server, whose scripts will read and write the database on the old server, and switch "www" to point to it. During the time when user's DNS caches are still live, some will point to the old server, but it will be sharing the same database, so both systems can run concurrently with no problem.
The glitch: images. Those are written to the filesystem rather than to the database, so images uploaded on one server will appear in the database of both, but only on one filesystem.
One way to fix this is to NFS-mount the image filesystem on both machines, but NFS is not terribly reliable and will increase network traffic.
Another way to do it is a more traditional switchover that will turn off the scripts on the old server when we enable to new one, and put up a static page that points people to the new server under a name other than "www" while their caches are still live.
Another thing to consider is moving "test" over first, pointing to the old database, and try the transition method on that before we try it on "www".
Jason, regardless of which way we go, you can start by reducing the lifetime of "test" and "www" in DNS, and make entries for "pliny" and "larousse". We also need to change the canonical name of ww to pliny--I can do that, but I'm not sure what else that might effect, so I haven't done it yet.
-- Lee Daniel Crocker lee@piclab.com http://www.piclab.com/lee/ "All inventions or works of authorship original to me, herein and past, are placed irrevocably in the public domain, and may be used or modified for any purpose, without permission, attribution, or notification."--LDC _______________________________________________ Wikitech-l mailing list Wikitech-l@wikipedia.org http://www.wikipedia.org/mailman/listinfo/wikitech-l