DBERROR db3: 4 lockers

[Paul M Fleming]

We found limiting the number of lmtp processes to 10 helped with locker
problems. Let sendmail/postfix  handle the queuing and lmtp the
delivery.. When we tried to blast 10-20 messages/sec at our test server
locking became a problem with the duplicate delivery db. Across 3
servers and 600 concurrent logins (lmtpd max=10 on each server) we never
see any locking problems and usually have <1 second delivery times.. 

Rob Siemborski wrote:
> 
> On Thu, 25 Sep 2003, Robert Covell wrote:
> 
> > We are in the process of replacing our 1.5.24 Cyrus box with a new 2.1.15
> > box.  After we got everything setup, tested and stabilized we rebooted the
> > box and got:
> >
> > Sep 25 16:12:09 mail1b ctl_cyrusdb[152]: checkpointing cyrus databases
> > Sep 25 16:12:09 mail1b lmtpd[155]: DBERROR db3: 4 lockers
> > Sep 25 16:12:09 mail1b ctl_cyrusdb[152]: done checkpointing cyrus databases
> > Sep 25 16:12:09 mail1b imapd[156]: DBERROR db3: 4 lockers
> > Sep 25 16:12:11 mail1b imapd[172]: DBERROR db3: 4 lockers
> 
> Note that in reality, esepcially for smaller sites, these messages on
> their own aren't a severe concern.  Only if the number is rapidly
> increasing should they be worried about.
> 
> > Is the recommendation of using skiplist with mailboxes.db still valid?  Or
> > do we need to shutdown the cyrus server before we shutdown?  If shutting it
> > down before a reboot what is the preferred method?  We are still in a
> > position to change the format if necessary before migrating 800+ users...
> 
> Yes.  You will need to recompile the cyrus server to do this. You will
> also want to dump the mailbox list beforehand, and undump it afterwords
> (as with any 1.x -> 2.x upgrade).
> 
> -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> Rob Siemborski * Andrew Systems Group * Cyert Hall 207 * 412-268-7456
> Research Systems Programmer * /usr/contributed Gatekeeper