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 usulimit -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