--On March 17, 2006 10:03:07 PM +0200 Mika Iisakkila
<[EMAIL PROTECTED]> wrote:
Rosenbaum, Larry M. wrote:
I did manage to get a couple minutes of truss output the other day but I
had to kill it before it finished. It looked very repetitive, with a
lot of this:
Well, it has to wade through every mailbox to check out that they
are OK. Five minutes for startup can be quite normal if you have
lots of mailboxes. That's I/O intensive stuff, so those plenty of
CPU cycles that you seem to have available might not help much there.
Mine sure doesn't. We've got 10k+ mailboxes and if Cyrus were to walk them
on startup it'd probably take an hour. It certainly doesn't. It might
walk the DB tree to check it's consistency but it certainly doesn't walk
the actual mailbox tree doing a consistency check during startup. If newer
versions do this I don't know, we're running a patched up 2.1.17 here. If
they do actually do that someone needs a cluebat, that's just a bad idea.
If it is to be done it needs to be done in the background, if at all. It's
better to assume things are OK and fix the errors as they come rather than
preventing 10k+ people from getting their mail for well over an hour, all
the while the support phones are ringing off the hook.
Ours was taking a while to do startup, turned out to be something wrong
with how cyrus is calling it's event handlers, the BDB log archives were
never getting cleaned despite having an event to do that. The log has to
be replayed every startup. If the BDB archive/aging was running right it'd
be retiring older transactions. No idea whats up there haven't ahd time to
look into it. It's not a major showstopper since it took nearly 2 yrs to
get to a size where it was a problem.
(Yes, I've always wondered myself what's happening back there
too, but never bothered to find out. Apparently Cyrus does this
in some brute-force way, one mailbox at a time -- in your truss
segment, it seems to read in three megabytes' worth of mailboxes.db
file over and over again.)
--mika
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