missing directories when using berkeley for seenstate_db

[Bron Gondwana]

On Wed, Jan 11, 2012, at 06:40 PM, Thilo Uttendorfer wrote:
> On Wednesday 11 January 2012 at 18:01:20, Bron Gondwana wrote:
> > On Wed, Jan 11, 2012 at 03:54:29PM +0100, Thilo Uttendorfer wrote:
> > > I recently switched the seenstate_db from skiplist to berkeley. It seems
> > > that the creation of directories is missing. I'm getting errors like
> > > this:
> >
> > Why would you do that?  Berkeley is being removed due to
> > difficult in upgrading.  I don't expect you will get
> > measurable benefits.
> >
> >[...]
> > Just out of interest - what version are you running?
> 
> I didn't know that berkeley is beeing removed, so skiplist will be the only 
> supported format?

Actually, probably a new format called twoskip, which fixes a few of the
shortcomings of skiplist, while been very stronly influenced by skiplist.

>From the twoskip.c file:

 * GOALS:
 *  a) 64 bit through
 *  b) Fast recovery after crashes
 *  c) integrity checks throughout
 *  d) simple format

We are currently running twoskip at FastMail in production for our
conversations database file.  I'm going to bring it in as a replacement
for skiplist everywhere else soon.

> We are using (kolab-) cyrus 2.2. The reason why we're using berkeley is that 
> it is (was?) recommended instead of skiplist, but that information is maybe 
> outdated. Nevertheless, we recently ran into corrupted seenstate files for 
> the first time (we usually had problems with corrupted mailboxes.db und 
> annotations.db). So we changed the seenstate file to berkeley as well - and 
> got the problems with the directories.

Skiplist in 2.2 has known bugs unfortunately.  Most of them got fixed between
2.3.4 and 2.3.8, with a couple of edge cases fixed in 2.3.12.

> I just had a look at the kolab changelog and found this:
> -----------
> kolabd-2.2.3-20091217
> 
> 	kolab/issue840  (Annotations needs to be more robust (skiplist
> 	                 problems)) as the now integrated imapd-2.3.13
> 	                 (see below) has additional skiplist fixes and
> 	                 the switch to berkeley-db for mailboxes.db
> 	                 and annotations.db introduced new problems we
> 	                 switched back to skiplist as default.
> -----------
> 
> So yes, my patch won't make much sense in recent installations.

We're not supporting 2.2 except for major security issues now, so yeah,
no point!

Regards,

Bron.
-- 
  Bron Gondwana
  brong at fastmail.fm