db upgrades in 2.4.x?

[Bron Gondwana]

On Tuesday, October 18, 2011 8:08 PM, "Zachariah Mully" <zmully at smartbrief.com> wrote:
> Howdy all-
> 	We're prepping for updating from 2.2.13->2.4.12 and I'm attempting to 
> figure out some of the database differences between the two to make sure 
> things go smoothly.
> 	We've already uncovered several issues in our testing that I've not 
> been able solve searching through the list archives:
> 1) Seen state updates
> 2) the purpose of /var/lib/cyrus/db
> 
> 	First, if I understand correctly, seen flags are now incorporated into 
> the cyrus.index file in 2.4.x. What I can't figure out is if there is 
> any way to manually trigger the reindexing of a single mailbox 
> cyrus.index file. A reconstruct doesn't appear to do it (just using the 
> -r flag).

Just the upgrade should copy the seen data in - but note it needs to be done
with the NEW code, you won't get a reindexing just by reconstructing with the
old reconstruct.

> 	When we do the cutover over, we've a tight deadline, and what I'd like 
> to do is reindex only the hot mailboxes, and then queue the remaining 
> ones for later. I don't think my users will tolerate loosing all their 
> Seen states, so I want to make sure we're preserving it while reducing 
> the re-indexing impact so that the server is still responsive.

The mailbox will be reindexed at the moment when it first gets opened.  The
rest will be re-indexed by cyr_expire when it runs regularly, if nothing
touches them before then.

> 	Is it possible to trigger a reindex manually of a single mailbox? How 
> are others dealing with this?

Just open it, it will upgrade.

> 	Second, I don't understand the purpose of the /var/lib/cyrus/db in 
> 2.4.12, it complained when the directory wasn't there, and I'm sure what 
> it's storing now that it is. Everything on our 2.4.12 install is either 
> skiplist or flat (sub), so what is that /db for?

skiplist stores a file (skipstamp) in there - and berkeley needs it just to
init.  Even if you're not actually using it.

Bron.
-- 
  Bron Gondwana
  brong at fastmail.fm