problems after upgrade from 2.2.27 to 2.3.4.1

[Aki Tuomi]

> On 09/12/2020 09:24 Lampa <lampacz at gmail.com> wrote:
> 
> 
> Hello,
> 
> after debian version from 9 to, also dovecot was upgraded. There was problems with right imap and imap-login connection settings. I adjusted process_limit, service count increased /proc/sys/net/core/somaxconn from 128 to 1024 for imap
> 
> It's a system with 1000+ imap and 200+ pop3 connections. When imap connections are over 1000 problems begins.
> 
> Problem one:
> 2020-12-07T12:46:39.575586+01:00 vhermes dovecot: master: Error: service(pop3): Initial status notification not received in 30 seconds, killing the process
> 2020-12-07T12:46:39.576448+01:00 vhermes dovecot: pop3: Fatal: master: service(pop3): child 13975 killed with signal 9
> 2020-12-07T12:46:42.015726+01:00 vhermes dovecot: master: Error: service(lmtp): Initial status notification not received in 30 seconds, killing the process
> 2020-12-07T12:46:42.016680+01:00 vhermes dovecot: lmtp: Fatal: master: service(lmtp): child 13985 killed with signal 9
> 2020-12-07T12:46:42.061963+01:00 vhermes dovecot: master: Error: service(lmtp): Initial status notification not received in 30 seconds, killing the process
> 2020-12-07T12:46:42.062973+01:00 vhermes dovecot: lmtp: Fatal: master: service(lmtp): child 13987 killed with signal 9
> 
> problem two:
> 2020-12-07T13:55:43.106017+01:00 vhermes dovecot: pop3: Error: net_connect_unix(/var/run/dovecot/stats-writer) failed: Resource temporarily unavailable
> 2020-12-07T13:56:22.300893+01:00 vhermes dovecot: lmtp: Error: net_connect_unix(/var/run/dovecot/stats-writer) failed: Resource temporarily unavailable
> 2020-12-07T13:58:11.721892+01:00 vhermes dovecot: imap: Error: net_connect_unix(/var/run/dovecot/stats-writer) failed: Resource temporarily unavailable
> 
> problem three - lot of
> 2020-12-07T10:16:24.773347+01:00 vhermes dovecot: imap-login: Error: master(imap): net_connect_unix(imap) failed: Resource temporarily unavailable - http://wiki2.dovecot.org/SocketUnavailable
> 


Your client_limit is too low. Try increasing it for these services.

<snip/>

> Seems that last problem is solved (if same) https://github.com/dovecot/core/commit/a668d767a710ca18ab6e7177d8e8be22a6b024fb
> 
> Thank you for any help
> 
> -- 
> 
> Lampa

Aki