BDB problems with lockers.

[Simon Matter]

> Cyrus users,
>
> I have been having a problem with my cyrus 2.2.13 install over the last
> couple of days.
>
> First I keep getting this DBERROR log:
>
> --------------------------------------------------------------------
> Jul  1 15:37:55 server lmtpunix[18456]: DBERROR db4: 49980 lockers
> --------------------------------------------------------------------
>
> Several messages I read on the list stated to ignore it, it wasn't a big
> deal, however this doesn't seem to apply on larger installations that
> eventually fill the lock table:
>
> --------------------------------------------------------------------
> Jul  1 15:42:50 server imaps[20139]: DBERROR db4: Lock table is out of
> available locker entries
> Jul  1 15:42:50 server imaps[20139]: DBERROR: opening
> /var/spool/imap/tls_sessions.db: Cannot allocate memory
> Jul  1 15:42:50 server imaps[20139]: DBERROR: opening
> /var/spool/imap/tls_sessions.db: cyrusdb error
> Jul  1 15:47:05 server lmtpunix[21385]: DBERROR db4: Lock table is out
> of available locker entries
> Jul  1 15:47:05 server lmtpunix[21385]: DBERROR: opening
> /var/spool/imap/deliver.db: Cannot allocate memory
> Jul  1 15:47:05 server lmtpunix[21385]: DBERROR: opening
> /var/spool/imap/deliver.db: cyrusdb error
> --------------------------------------------------------------------
>
> So now we have a problem, the database quits and eventually becomes
> corrupted:
>
> --------------------------------------------------------------------
> Jul  1 15:47:06 server lmtpunix[20989]: DBERROR db4: 50000 lockers
> Jul  1 15:47:07 server lmtpunix[21391]: DBERROR db4: Lock table is out
> of available locker entries
> Jul  1 15:47:07 server lmtpunix[21391]: DBERROR db4: PANIC: Cannot
> allocate memory
> Jul  1 15:47:07 server lmtpunix[21391]: DBERROR: critical database
> situation
> Jul  1 15:47:07 server lmtpunix[21407]: DBERROR db4: PANIC: fatal region
> error detected; run recovery
> --------------------------------------------------------------------
>
> So now the question is how do I fix this?  I am running BDB-4.2.52 with
> all 4 patches so the only thing I can do with bdb is to upgrade to the
> 4.4.20 release, but I'm unsure if this release is any more stable.  My
> mailboxes file seems safe since it is in skiplist format, so maybe I
> should convert the deliver database to skiplist as well?

Yes, move to skiplist and you're done.

>
> What about cyrus 2.3.6?  Is this stable enough for a large server?  Does
> it work around any of the BDB problems?

Your problem is not Cyrus but BDB, you really want skiplist.

Simon