Good day / evening / morning good dovecot people:
Overview:
We are seeing the following issue on one of our servers:
pop3-login: Error: master(pop3): net_connect_unix(pop3) failed: Resource
temporarily unavailable - http://wiki2.dovecot.org/SocketUnavailable
(client-pid=5418, client-id=1, rip=__REMOVED__, created 534 msecs ago, received
0/4 bytes)
We tried tuning the pop3-login -> client_limit parameter. However, as soon as
we increased this parameter (and after restarting dovecot), we saw an onslaught
of lmtp connection errors in postfix (unable to deliver via lmtp to dovecot).
This led us to set the pop3-login -> client_limit back to 1000 again and the
lmtp errors disappeared.
This leads me to think that we should tune some other parameters as well.
Increase overall limits or such. It seems like when increasing the client_limit
for pop3-logins that somehow affected the lmtp deliverability.
If anyone has any input on this that would be much appreciated.
Cheers,
Martin
--
Version and config:
# dovecot --version
2.2.36 (1f10bfa63)
# dovecot -n
# 2.2.36 (1f10bfa63):
# OS: Centos 7.7
# Hostname:
auth_mechanisms auth_verbose = yes
base_dir = __REMOVED__
default_client_limit = 2500
disable_plaintext_auth = no
doveadm_password first_valid_uid = 89
last_valid_uid = 89
lmtp_rcpt_check_quota = yes
login_greeting login_trusted_networks mail_gid = 89
mail_plugins = " notify replication quota"
mail_uid = 89
mbox_write_locks = fcntl
namespace inbox {
inbox = yes
location prefix }
passdb {
args driver = ldap
}
plugin {
mail_replica = tcps:
quota = maildir:User quota
quota_rule }
protocols = pop3 lmtp
replication_full_sync_interval = 3 hours
replication_max_conns = 20
service aggregator {
fifo_listener replication-notify-fifo {
group = postfix
mode = 0640
user = postfix
}
unix_listener replication-notify {
group = postfix
mode = 0640
user = postfix
}
}
service auth {
unix_listener auth {
mode = 0660
}
}
service doveadm {
inet_listener {
port = 12345
ssl = yes
}
}
service lmtp {
process_min_avail = 10
unix_listener lmtp {
group = postfix
mode = 0640
user = postfix
}
}
service pop3-login {
client_limit = 1000
process_limit = 2048
process_min_avail = 10
service_count = 1
}
service pop3 {
client_limit = 1
process_limit = 2048
process_min_avail = 0
service_count = 1
}
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<https://dovecot.org/pipermail/dovecot/attachments/20210413/4e7def79/attachment-0001.html>