Increasing mail_max_userip_connections and sys resources

[Nikolaos Milas]

On 14/1/2016 7:19 μμ, Nikolaos Milas wrote:

> 2. Could another dovecot setting prevent the above setting from being 
> applied (e.g. due to connections exhaustion), i.e. should we also 
> change other setting(s)? 

An associated question:

I tried adding "process_limit = 2048" to imap:

    protocol imap {
       imap_client_workarounds = "delay-newmail"
       mail_plugins = quota imap_quota notify replication
       process_limit = 2048
       mail_max_userip_connections = 100
    }

but this leads to:

    # doveconf -n

    # 2.2.18: /etc/dovecot/dovecot.conf
    # Pigeonhole version 0.4.8
    doveconf: Fatal: Error in configuration file
    /etc/dovecot/dovecot.conf line 30: Unknown setting: process_limit
    doveconf: Error: managesieve-login: dump-capability process returned 89
    doveconf: Fatal: Error in configuration file
    /etc/dovecot/dovecot.conf line 30: Unknown setting: process_limit

However, here: 
http://wiki.dovecot.org/Services#imap.2C_pop3.2C_managesieve I read:

    imap, pop3, managesieve

    process_limit defaults to 1024, which means that the number of
    simultaneous IMAP (or POP3 or ManageSieve) connections is limited by
    this setting. If you expect more connections, increase this value.

So, I was not expecting this error and can't see what's the problem.

Why "process_limit" is an unknown setting? What am I doing wrong?

Please clarify!

Thanks,
Nick