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
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