The database deadlocking gremlins usually cause an lmtpd or imapd
process to crash while holding a database lock. The number one thing
is to find out which process crashed, why it crashed, and to stop it.
The master should syslog whenever a process exiting abnormally
("grep signal /var/log/cyrus.log").
We're using Berkeley db 3.1.17 on Solaris 2.7 and haven't had any
problems since upgrading to Cyrus 2.1, though we use a flat text
mailboxes file. (But there's still the deliverdb/tls database).
Michael, when you say you're going to compile a all cyrusdb_flat,
which version are you talking about? Making deliverdb use a flat text
file would really hurt performance.
To get things straight, by default:
Cyrus 2.0.16 uses Berkeley db w/ txns for mailboxes.
It uses Berkeley db w/o txns for deliverdb (and has for a long time).
It uses flat text files for storing seen state.
Cyrus 2.1 uses Berkeley db w/ txns for mailboxes.
It uses Berkeley db w/ txns for deliverdb.
It uses flat text files for storing seen state.
It uses Berkeley db w/ txns for storing TLS session information.
We run Cyrus 2.1 with:
flat mailboxes
db3_nosync deliverdb
flat seen state
db3_nosync TLS
I'm working on another reliable non-Sleepycat format for the mailboxes
file since it's become apparent that no large volume site can use
Sleepycat. I don't see any reasonable alternatives for deliverdb or
TLS information right now.
Larry
Date: Tue, 15 Jan 2002 16:32:01 -0500
From: Michael Bacon <[EMAIL PROTECTED]>
You've apparently made the aquaintance of the database deadlocking
gremlins. We've been running into this one since upgrading to 2.0.16, and
have yet to find a good solution for it. Because we've finally gotten sick
of them, we're about to install a version of cyrus that was recompiled
using all cyrusdb_flat instead of cyrusdb_db3 to see if it helps. In the
meantime, you can probably cut down on the frequency of the errors by
setting prefork=0. I don't know why, but the preforks seem to make the
problem happen more frequently.
Michael Bacon
Duke University
[EMAIL PROTECTED]
--On Tuesday, January 15, 2002 15:52:59 -0500 Chris Peck <[EMAIL PROTECTED]>
wrote:
> Yesterday I started to see (for the first time since upgrading to
> cyrus-2.0.16 on Jan 4th) a lot of messages from sendmail which indicated:
> "Could not connect to socket /var/imap/socket/lmtp: Connection refused by
> localhost". I checked and there were no lmtpd processes running, even
> though my cyrus.conf indicated a prefork=1 for them. This, of course,
> really messes up our mail delivery, since mail is coming in, but, it's
> not getting delivered. I stopped sendmail & cyrus master, then started
> cyrus master & sendmail & it started up fine. About 4 hours later, the
> same thing happened. Once again I went through the restart process. I
> then rebooted our system around 6:00 pm last night (students return
> today), and all was fine until around 1:30 this afternoon, when I started
> getting the same messages in syslog, but, there were about 30 lmtpd's
> running (over 100 sendmail's). This time I waited & after a few minutes
> lmtp would accept the connects, then reject them, etc. Finally, I went
> through the restart process & it has been running fine since.
>
> Needless to say, I am very concerned about this. It sounds like I'm
> running into a resource problem, but, I have checked swap, disk space,
> memory usage, etc, and all seems fine. Is it possible that I need to
> increase a network resource? Or maybe, tell master to increase his
> listen queue on startup?
>
> Here's the cyrus.conf file:
>#
># cyrus.conf
>#
># taken from prefork.conf as distributed with cyrus
># 20011010 - initial create date <crpeck>
>#
>
> START {
> # do not delete these entries!
> mboxlist cmd="ctl_mboxlist -r"
> deliver cmd="ctl_deliver -r"
>
> # this is only necessary if using idled for IMAP IDLE
> # idled cmd="idled"
> }
>
># UNIX sockets start with a slash and are put into /var/imap/sockets
> SERVICES {
> # add or remove based on preferences
> imap cmd="imapd" listen="imap" prefork=5
> imaps cmd="imapd -s" listen="imaps" prefork=1
> pop3 cmd="pop3d" listen="pop3" prefork=5
> pop3s cmd="pop3d -s" listen="pop3s" prefork=1
> sieve cmd="timsieved" listen="sieve" prefork=0
>
> # at least one LMTP is required for delivery
># lmtp cmd="lmtpd" listen="lmtp" prefork=0
> lmtpunix cmd="lmtpd" listen="/var/imap/socket/lmtp" prefork=1
> }
>
> EVENTS {
> # this is required
> checkpoint cmd="ctl_mboxlist -c" period=30
>
> # this is only necessary if using duplicate delivery suppression
> delprune cmd="ctl_deliver -E 3" period=1440
> }
>
> Any suggesations on where to start would be appreciated...
>
> -thanks
> chris
>
>
> Chris Peck
> Manager of Unix Services
> Information Technology
> The College of William and Mary
> Williamsburg, VA 23187
>
>
