Hi Philips,
I have the same error after upgrade from dovecot 2.2 to dovecot 2.3,
could be related to "service stats",
try to grep in the dovecot.log for "reached" and look for an error like:
dovecot: master: Warning: service(stats): client_limit (1000) reached,
client connections are being dropped
If you find it add to 10-master.conf:
service stats {
client_limit = 10240
unix_listener stats-writer {
mode = 0660
#user = vmail
#group = vmail
}
}
then restart dovecot.
Let me know if you solve or find others limit reached in the log.
Ciao
Il 31/03/20 18:22, Philipp Ewald ha scritto:
Hello everyone,
we have a huge problem with dovecot and IMAP connections.
we got the following errors: 39665 today
dovecot: imap-login: Error: master(imap): net_connect_unix(imap)
failed: Resource temporarily unavailable -
http://wiki2.dovecot.org/SocketUnavailable (client-pid=29066,
client-id=1755, rip=IP, created 562 msecs ago, received 0/4 bytes)
we thinks this may be a problem with authorization take too long?
Authorization is not local and with SQL.
i found the following in source code of Dovecot:
#define SOCKET_CONNECT_RETRY_MSECS 500
#define SOCKET_CONNECT_RETRY_WARNING_INTERVAL_SECS 2
[...]
i_error("master(%s): %s (client-pid=%u, client-id=%u, rip=%s, created
%u msecs ago, received %u/%zu bytes)",
This is no process limit problem:
ps auxf | grep -c "[d]ovecot/imap$"
688
ps auxf | grep -c "[d]ovecot/imap-login$"
100
cat /proc/`pidof dovecot`/limits
Limit Soft Limit Hard Limit Units
Max cpu time unlimited unlimited seconds
Max file size unlimited unlimited bytes
Max data size unlimited unlimited bytes
Max stack size 8388608 unlimited bytes
Max core file size 0 unlimited bytes
Max resident set unlimited unlimited bytes
Max processes 64053 64053 processes
Max open files 65535 65535 files
Max locked memory 65536 65536 bytes
Max address space unlimited unlimited bytes
Max file locks unlimited unlimited locks
Max pending signals 64053 64053 signals
Max msgqueue size 819200 819200 bytes
Max nice priority 0 0
Max realtime priority 0 0
Max realtime timeout unlimited unlimited us
ulimit -n
1024
dovecot --version
2.3.4.1 (f79e8e7e4)
protocols = imap pop3
service imap-login {
process_min_avail = 4
service_count = 0
}
service imap {
process_limit = 4096
}
service pop3-login {
process_min_avail = 4
service_count = 0
}
service pop3 {
process_limit = 4096
}
Can someone explain why we got this error and how to fix? If you need
another information please tell me.
--
Alessio Cecchi
Postmaster @ http://www.qboxmail.it
https://www.linkedin.com/in/alessice