dovecot - Nov 2020 - about imap-login: Error and imap: Error after Version-UP

Hi.. 

there is supposed to be only at most one (1) stats process. Having multiple
stats processes breaks stats.

Aki
> On 18/11/2020 01:48 ????? <morikawa-k6 at itec.hankyu-hanshin.co.jp>
wrote:
> 
>  
> Aki-san
> 
> Last night We adjusted the "process_limit" in the stats service
to get rid of the error.
> 
> "client_limit" is in the blank (default) state.
> 
> Thank you very much.
> 
> morikawa
> -----Original Message-----
> From: 'Aki Tuomi' [mailto:aki.tuomi at open-xchange.com] 
> Sent: Tuesday, November 17, 2020 2:35 PM
> To: ????? <morikawa-k6 at itec.hankyu-hanshin.co.jp>; dovecot at
dovecot.org
> Subject: RE: about imap-login: Error and imap: Error after Version-UP
> 
> You need to configure stats service client limit and imap service client
limit. Those are different services than imap-login service.
> 
> Aki
> 
> > On 17/11/2020 01:28 ????? <morikawa-k6 at
itec.hankyu-hanshin.co.jp> wrote:
> > 
> >  
> > Aki-san
> > 
> > I have already seen that page.
> > Is the setting method wrong?
> > 
> > Is there any other tuning point?
> > 
> > morikawa
> > -----Original Message-----
> > From: Aki Tuomi [mailto:aki.tuomi at open-xchange.com]
> > Sent: Monday, November 16, 2020 8:52 PM
> > To: ????? <morikawa-k6 at itec.hankyu-hanshin.co.jp>; dovecot at
dovecot.org
> > Subject: Re: about imap-login: Error and imap: Error after Version-UP
> > 
> > 
> > > On 16/11/2020 13:44 ????? <morikawa-k6 at
itec.hankyu-hanshin.co.jp> wrote:
> > > 
> > >  
> > > We have upgraded dovecot from 2.0.9 (centos6) to 2.2.36
(centos8).
> > > 
> > > If more than 1000 users log in, the following error will occur.
> > > -------------------------
> > > Nov 16 11:33:00 xxxxxxxx dovecot[1361]: imap-login: Error:
master(imap):
> > > net_connect_unix(imap) failed: Resource temporarily unavailable -
> > > http://wiki2.dovecot.org/SocketUnavailable (client-pid=1362, 
> > > client-id=129834, rip=10.10.10.10, created 551 msecs ago,
received
> > > 0/4
> > > bytes)
> > > Nov 16 11:30:26 xxxxxxxx dovecot[1361]: imap: Error:
> > > net_connect_unix(/var/run/dovecot/stats-writer) failed: Resource 
> > > temporarily unavailable
> > > -------------------------
> > > 
> > > I set the following because I thought it was a problem with the 
> > > number of connections, but I get an error.
> > > 
> > > service imap-login {
> > >   service_count=0
> > >   client_limit = $default_client_limit
> > >   process_min_avail = 4
> > >   process_limit = $default_process_limit
> > >   vsz_limit = 1G
> > > }
> > > 
> > > limits.conf
> > > -------------------------
> > > * soft nofile 4096
> > > * hard nofile 4096
> > > -------------------------
> > > 
> > > cat /proc/sys/net/core/somaxconn
> > > -------------------------
> > > 4096
> > > -------------------------
> > > 
> > > Is there any other tuning point?
> > > Where should I look?
> > 
> > https://wiki.dovecot.org/SocketUnavailable
> > 
> > Aki