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<p>Hi,</p>
<p><b>Our setup:</b></p>
<p>Two Debian 10 machines that are setup to replicate mail between
them, we have round robin DNS setup so a user can connect to
either server. <br>
</p>
<p><b>What should happen:</b></p>
<p>Mail is delivered to either server and replicated across straight
away to their mailbox on the other server so it does not matter
which one they are connected to they will receive it fairly soon
after delivery.</p>
<p><b>What actually happens:</b></p>
<p>In some instances the user will experience a delayed receipt of
messages if they are not connected to the server that the message
is initially delivered to, sometimes the delay is 5/10 minutes, we
had a recent support ticket submitted where it was over an hour.</p>
<p>Error message seen in mail.err:<br>
</p>
<p>Sep 1 10:16:15 <host name> dovecot:
dsync-local(<username>)<WELSGEERTl8FEAAAZJ7A9A>:
Error: Couldn't lock /path/to/mailbox/.dovecot-sync.lock:
fcntl(/path/to/mailbox/.dovecot-sync.lock, write-lock, F_SETLKW)
locking failed: Timed out after 30 seconds (WRITE lock held by pid
3697)</p>
<p>Process 3697 is dovecot/doveadm-server.<br>
</p>
<p><b>Doveconf -n output:</b></p>
<p># 2.3.10.1 (a3d0e1171): /etc/dovecot/dovecot.conf<br>
# Pigeonhole version 0.5.10 (67bf5bd7)<br>
# OS: Linux 4.19.0-10-amd64 x86_64 Debian 10.5 <br>
# Hostname: <server hostname><br>
auth_verbose = yes<br>
default_vsz_limit = 0<br>
doveadm_password = # hidden, use -P to show it<br>
first_valid_gid = 8<br>
first_valid_uid = 8<br>
last_valid_gid = 8<br>
last_valid_uid = 8<br>
lda_mailbox_autocreate = yes<br>
lda_mailbox_autosubscribe = yes<br>
mail_gid = 8<br>
mail_location = maildir:~/Maildir<br>
mail_plugins = " notify replication"<br>
mail_uid = 8<br>
managesieve_notify_capability = mailto<br>
managesieve_sieve_capability = fileinto reject envelope
encoded-character vacation subaddress comparator-i;ascii-numeric
relational regex im<br>
ap4flags copy include variables body enotify environment mailbox
date index ihave duplicate mime foreverypart extracttext
editheader imapfla<br>
gs<br>
namespace inbox {<br>
inbox = yes<br>
location = <br>
mailbox Drafts {<br>
special_use = \Drafts<br>
}<br>
mailbox Junk {<br>
special_use = \Junk<br>
}<br>
mailbox Sent {<br>
special_use = \Sent<br>
}<br>
mailbox "Sent Messages" {<br>
special_use = \Sent<br>
}<br>
mailbox Trash {<br>
special_use = \Trash<br>
}<br>
prefix = <br>
}<br>
passdb {<br>
args = /etc/dovecot/dovecot-ldap.conf.ext<br>
driver = ldap<br>
}<br>
plugin {<br>
mail_replica = tcps:<server being replicated to>:<port
being used><br>
sieve = ~/.dovecot.sieve<br>
sieve_dir = ~/sieve<br>
sieve_extensions = +editheader +imapflags<br>
}<br>
postmaster_address = postmaster@<domain address><br>
protocols = " imap sieve pop3"<br>
replication_max_conns = 12<br>
service aggregator {<br>
fifo_listener replication-notify-fifo {<br>
user = mail<br>
}<br>
unix_listener replication-notify {<br>
user = mail<br>
}<br>
}<br>
service auth {<br>
unix_listener /var/run/dovecot-exim-bridge {<br>
mode = 0660<br>
user = Debian-exim<br>
}<br>
}<br>
service doveadm {<br>
inet_listener {<br>
port = <port being used for replication><br>
ssl = yes<br>
}<br>
}<br>
service imap-login {<br>
inet_listener imap {<br>
port = 143<br>
}<br>
}<br>
inet_listener imaps {<br>
port = 993<br>
ssl = yes<br>
}<br>
process_limit = 512<br>
process_min_avail = 4<br>
service_count = 1<br>
}<br>
service imap {<br>
process_limit = 1024<br>
}<br>
service managesieve-login {<br>
inet_listener sieve {<br>
port = <sieve port><br>
}<br>
process_min_avail = 1<br>
service_count = 8<br>
vsz_limit = 256 M<br>
}<br>
service managesieve {<br>
process_limit = 1024<br>
}<br>
service replicator {<br>
process_min_avail = 1<br>
unix_listener replicator-doveadm {<br>
mode = 0666<br>
}<br>
}<br>
ssl = required<br>
ssl_cert = </path/to/ssl/cert/fullchain.pem<br>
ssl_cipher_list = ALL:!LOW:!SSLv2:!EXP:!aNULL<br>
ssl_client_ca_dir = /etc/ssl/certs<br>
ssl_key = # hidden, use -P to show it<br>
ssl_min_protocol = TLSv1.2<br>
userdb {<br>
args = /etc/dovecot/dovecot-ldap.conf.ext<br>
driver = ldap<br>
override_fields = home=/var/mail/%u uid=mail gid=mail<br>
}<br>
protocol lda {<br>
mail_plugins = " notify replication sieve"<br>
}<br>
protocol imap {<br>
mail_max_userip_connections = 32<br>
mail_plugins = " notify replication"<br>
}<br>
protocol sieve {<br>
mail_max_userip_connections = 10<br>
managesieve_logout_format = bytes=%i/%o<br>
managesieve_max_line_length = 65536<br>
}<br>
<br>
</p>
<p>Kind regards</p>
<p>Daniel</p>
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