BDB problems with lockers.

[Matthew Schumacher]

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?

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

Thanks,
schu