Re: Odd replication behaviour

31 Oct 2020


      Solved. I knew this would happen. The act of writing it all out and including the configuration output gave me the solution.
I am using lmtp to deliver mail from postfix to Dovecot. I was missing the notify and replication plugins from 20-lmtp.conf
They were only present in 10-mail.conf as
mail_plugins = notify replication
Now, adding to 20-lmtp.conf:
protocol lmtp {
mail_plugins = sieve notify replication
}
Works fine now. Hope this helps someone else.
Cheers
James
...
On 31 Oct 2020, at 14:40, James Pattinson james@pattinson.org wrote:
Hi,
I have just built a new pair of similar machines both running CentOS 8.2 (selinux disabled) and Dovecot 2.3.8 (9df20d2db).
One machine is a VPS (host A) and one is on my home network (host B). The idea is that they are set up in a master/master config with Dovecot replication.
I seem to have this 95% working but there is one strange issue I can’t work out.
Currently B is a perfect replica of A. I have pointed an instance of Thunderbird at it, and I can see all my mails. If I delete any mails or change any flags, I see the same changes almost instantly on the A side.
PROBLEM: if host A receives a new mail, I don’t see it on B until I do ‘something’ to change metadata, for example deleting any random email, or marking an email as read on EITHER side causes the new email to appear almost instantly on the B side.
I would have expected emails on B to appear immediately. Am I doing something wrong?
Extra info -  my mailboxes are in Maildir format with single OS user (vmail). I have about 4000 emails in the Inbox and about 30k in other folders.
There are only 5 users and I’m using passdb as the very simple backend.
Replication is via doveadm on a specified port (not SSH). Some output from dovecot -n is below.
Cheers
James
HOST A
# 2.3.8 (9df20d2db): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.5.8 (b7b03ba2)
# OS: Linux 4.18.0-193.28.1.el8_2.x86_64 x86_64 CentOS Linux release 8.2.2004 (Core)  xfs
# Hostname: hosta.domain
auth_mechanisms = plain login
doveadm_password = # hidden, use -P to show it
doveadm_port = 4040
first_valid_uid = 1000
mail_debug = yes
mail_home = /srv/vmail/%u
mail_location = maildir:/srv/vmail/%u
mail_plugins = notify replication
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date index ihave duplicate mime foreverypart extracttext
mbox_write_locks = fcntl
namespace inbox {
inbox = yes
location =
mailbox Drafts {
auto = subscribe
special_use = \Drafts
}
mailbox Junk {
auto = subscribe
special_use = \Junk
}
mailbox Sent {
special_use = \Sent
}
mailbox "Sent Messages" {
special_use = \Sent
}
mailbox Trash {
auto = subscribe
special_use = \Trash
}
prefix =
}
passdb {
args = scheme=BLF-CRYPT username_format=%u /etc/dovecot/users
driver = passwd-file
}
plugin {
mail_replica = tcp:b.b.b.b:4040
sieve = file:~/sieve;active=~/.dovecot.sieve
sieve_before = /var/mail/SpamToJunk.sieve
}
protocols = imap lmtp
service aggregator {
fifo_listener replication-notify-fifo {
group = root
mode = 0660
user = vmail
}
unix_listener replication-notify {
group = root
mode = 0660
user = vmail
}
}
service auth {
unix_listener /var/spool/postfix/private/auth {
group = postfix
mode = 0600
user = postfix
}
}
service doveadm {
inet_listener {
port = 4040
}
}
service lmtp {
unix_listener /var/spool/postfix/private/dovecot-lmtp {
group = postfix
mode = 0600
user = postfix
}
}
service replicator {
process_min_avail = 1
unix_listener replicator-doveadm {
mode = 0600
user = vmail
}
}
ssl = required
ssl_cert = 
HOST B
# 2.3.8 (9df20d2db): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.5.8 (b7b03ba2)
# OS: Linux 4.18.0-193.28.1.el8_2.x86_64 x86_64 CentOS Linux release 8.2.2004 (Core)  ext4
# Hostname: hostb
auth_mechanisms = plain login
doveadm_password = # hidden, use -P to show it
doveadm_port = 4040
first_valid_uid = 1000
mail_debug = yes
mail_home = /srv/vmail/%u
mail_location = maildir:/srv/vmail/%u
mail_plugins = notify replication
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date index ihave duplicate mime foreverypart extracttext
mbox_write_locks = fcntl
namespace inbox {
inbox = yes
location =
mailbox Drafts {
auto = subscribe
special_use = \Drafts
}
mailbox Junk {
auto = subscribe
special_use = \Junk
}
mailbox Sent {
special_use = \Sent
}
mailbox "Sent Messages" {
special_use = \Sent
}
mailbox Trash {
auto = subscribe
special_use = \Trash
}
prefix =
}
passdb {
args = scheme=BLF-CRYPT username_format=%u /etc/dovecot/users
driver = passwd-file
}
plugin {
mail_replica = tcp:a.a.a.a:4040
sieve = file:~/sieve;active=~/.dovecot.sieve
sieve_before = /var/mail/SpamToJunk.sieve
}
protocols = imap lmtp
service aggregator {
fifo_listener replication-notify-fifo {
group = root
mode = 0660
user = vmail
}
unix_listener replication-notify {
group = root
mode = 0660
user = vmail
}
}
service auth {
unix_listener /var/spool/postfix/private/auth {
group = postfix
mode = 0600
user = postfix
}
}
service doveadm {
inet_listener {
port = 4040
}
}
service lmtp {
unix_listener /var/spool/postfix/private/dovecot-lmtp {
group = postfix
mode = 0600
user = postfix
}
}
service replicator {
process_min_avail = 1
unix_listener replicator-doveadm {
mode = 0600
user = vmail
}
}
ssl = required
ssl_cert =