db4 backend alternative

[Mark Hannessen]

On Monday 20 December 2004 23:25, you wrote:
> Hi Mark,
>
> I'm looking for information as to how to convert from BDB4 to skiplist.

well, I don't have any real info or tools...

I only had 4 mail adresses at that time so I just copied all the mail using 
imap from my old to the new server. might be doable with 50 clients as 
well... though it is very braindead. suppose you could also write a script in 
perl to do it for you.

> I've finished with a new install of SASL, Cyrus IMAP, Postfix, MySQL,
> Web-Cyradm. I followed a how-to doc from Luc de Louw
> (www.web-cyradm.org). I've got the install completed and am in
> authentication testing phase. It looks like things are running ok.
> Recently, I've been paying attention to Berkeley DB complaints on the
> Cyrus mailing lists. Frankly, they have me concerned. The mail server
> I'm creating will be a corporate production mail server, but only
> serving 50 clients and 80GB of mail storage. I thought now would be a
> good time to possibly convert to skiplist before I populate the mail
> server.
>
> Can you point me to any docs on how to accomplish this? Does it mean
> recompiling SASL and IMAP, or is a config file change?

I added the following to my imapd.conf

annotation_db: skiplist
duplicate_db: skiplist
mboxlist_db: skiplist
ptscache_db: skiplist
quota_db: skiplist
seenstate_db: skiplist
subscription_db: skiplist
tlscache_db: skiplist

this will make sure everything will be stored in skiplist databases.

> Pardon my 
> ignorance, but what is skiplist? I'm having a hard time researching
> because I don't know much about it.

I don't have any real knowledge about skiplist other then that it is a 
database backend that seems to be used exclusively by cyrus imap.

> Any help is greatly appreciated.
>
> Thanks,
>
> Mark Butscher
>
> Mark Hannessen wrote:
> > lol, so this thread is still running..
> > been a while since I started it.
> >
> > I must say i am very pleased with skiplist, I have simulated a few
> > hunderd crashes and it was able to recover every time. with db4 I had to
> > pray for a succesfull restart or lose all my mail. (not kidding)
> >
> > the reason I switched to linux wasn't speed... because speed is cheap.
> >
> > it was stability and security.
> >
> > I think that in general people with few users won't care about the little
> > random seek speed gain from db4, and people with many many many users
> > would like to go to sleep at night, knowing that when they wake up there
> > cyrus server is still having a good time handing mail over to users.
> >
> > I am not a technical dude, skiplist might be plain ugly, but from my
> > perspective it works at what it is supposed to do. db4 fails that
> > purpose.
> >
> > If I had to choose, skiplist would be the default a not db4. think about
> > the bad impression it gives when new users see cyrus imap destroy all
> > there mail before there eyes while doing a simple cyrus reboot. you would
> > lose all faith in that product and switch to another one right?
> >
> > And the worst thing it that this isn't needed at all.
> > cyrus is a good product. but people won't use it if they can't see that.
> >
> > regards from a happy cyrus user,
> >
> > Mark Hannessen
> >
> > On Friday 10 December 2004 13:18, you wrote:
> >>Michael Sims wrote:
> >>>Denny Schierz wrote:
> >>>>Am Montag, den 22.11.2004, 22:51 +0000 schrieb Mark Hannessen:
> >>>>>I am really wondering about this because I just can't seem to get
> >>>>>db4 to run stable.
> >>>>
> >>>>same problem here. I have to delete once a week all db's (but
> >>>>mailboxes.db). Otherwise i have timeouts and bouncing mails :-/
> >>>
> >>>Seriously, why don't you guys switch to skiplist and avoid the whole
> >>>Berkeley DB mess?  I switched to skiplist for mailboxes.db, deliver.db,
> >>>and the seen databases (on 2.1.x) about a year and a half ago and
> >>> haven't had a problem since.  Berkeley DB
> >>
> >>Same here. Switched a year ago and not a worry in the world.
> >>The only difference is that I'm using deliver with db3-nosync (as with
> >>the tls_sessions) and the subscribed folders databases are flat files.
> >>The rest is all skiplist.
> >>
> >>>may perform better in some situations, but IMHO it's not worth the
> >>> hassle it brings. YMMV...
> >>
> >>Regards
> >
> > ---
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