On Wed, Mar 17, 2010 at 3:12 PM, Mark Moseley <moseleymark@gmail.com> wrote:
On Wed, Mar 17, 2010 at 1:09 PM, Timo Sirainen <tss@iki.fi> wrote: <snip>
I don't know if anyone has run local indexes in larger setups, so I can't really give any good answers. The worst case of rebuilding the whole index isn't anyway any worse than what Courier has to do every time.
I'll check it out. And if we go that route and I'm still sane at the end, I'll be sure to report back :)
Update on this one point:
We've been running local indexes for a while now and it's worked wonderfully. The load balancers in front of 2 groups of 30 IMAP servers are doing a sticky-source persistence of a day. Our NFS reads/sec dropped by literally 8x by moving to Dovecot, even with the local indexes--looking at the graphs, it's a seriously jaw-dropping plummet. I've not heard a single complaint of corruption. Next step is to get the indexes on SSDs just to squeeze out a few extra jiffies.
All in all, it's been remarkably successful (and almost bizarrely gotcha-free -- though I haven't tackled POP3 yet). Our formerly irate IMAP users are all sweetness and light now. Thanks Timo!