Upgrade 2.2.27 to 2.3.9.2: master(imap): net_connect_unix(imap) failed: Resource temporarily unavailable

[Eirik Rye]

On 08/01/2020 10:49, Eirik Rye wrote:
> [...]

In any case, the biggest issue is the one described in the original 
message in this thread, where logins are periodically failing for many 
for users:

2020-01-08T10:54:57.436400+01:00 imap dovecot: imap-login: Error: 
master(imap): net_connect_unix(imap) failed: Resource temporarily 
unavailable - http://wiki2.dovecot.org/SocketUnavailable
2020-01-08T10:54:57.437550+01:00 imap dovecot: imap-login: Internal 
login failure

At the same time:

~# ps aux | grep "dovecot/imap$" | wc -l
6637
~# doveadm process status | grep "^imap " | wc -l
6660
~# cat /proc/`pidof dovecot`/limits | grep "open files"
Max open files            32768                32768                files
~# doveconf -n
[...]
service imap-login {
   client_limit = 2500
   inet_listener imap {
     port = 143
   }
   inet_listener imaps {
     port = 993
     ssl = yes
   }
   process_limit = 16
   process_min_avail = 16
   service_count = 0
   vsz_limit = 512 M
}
service imap {
   client_limit = 1
   process_limit = 20000
}

-- 
Eirik