[Zope] Migration Strategy
J. Cameron Cooper
jccooper at jcameroncooper.com
Mon Oct 20 19:05:38 EDT 2003
> We're moving some content from Zope 2.6 to 2.6.2, and I'm wondering
> what the best way to do this would be.
> In the fantasy world that is my mind, I think I'd be looking for a way
> to safely lock the ZODB in the 2.6 instance, so we can migrate to
> 2.6.2 while still serving (unchangeable) content from 2.6.
If you have an INSTANCE_HOME setup, you can install the new version
alongside the old, turn off the old version, change the INSTANCE_HOME
variable (I actually change a symbolic link under Linux) and turn the
new one on within whatever time it takes to restart your site.
It you have a ZEO setup, this can be done even faster, possibly
instantaneously: you could have both new and old running off the same
ZODB but on different ports, and when you wanted to cut over, make your
proxy/cache/firewall-port-forwarder point to the new port.
If you're actually talking separate instance (and not just upgrading an
instance) then you could remove all permissions for changing content
from whatever roles your usual users have until you've moved everything
you need to move. But there is no safe low-level way to make the ZODB
"My point and period will be throughly wrought,
Or well or ill, as this day's battle's fought."
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