[Dovecot] many instances om imap and imap-login

[Dominic Marks]

On Tuesday 26 April 2005 15:19, you wrote:
> Thanks for extensive answer.
>
> I will look into all your suggestions.

Please keep the mailing list in the response, it allows other people to 
provide advice, follow the conversation, and you get, hopefully, complete 
solutions stored in the archives waiting for Google to index.

> Answers to you questions:
>
> Are the mailboxes being accessed via Webmail?:
> 	yes they can but arent at the moment (squirrelmail)

Webmail can cause lots of extra connections to me made.

> What Mail application are your users using?:
> 	Thunderbird 1.0.2

Don't have much experience with this client, although it works when I've tried 
it. Others may be able to provide experience here.

> Have you checked what state the connections are in?:
> 	 Do you mean of they are connected or not? when I run top I do see
> instances called IMAP owned by each user so I asume they are connected

mail# netstat -f inet -p tcp | grep imap
tcp4       0      0  mailserver.imap        client01.1386          ESTABLISHED
tcp4       0      0  mailserver.imap        client02.1344          ESTABLISHED
tcp4       0      0  mailserver.imap        client01.1108          ESTABLISHED
tcp4       0      0  mailserver.imap        client03.54607        ESTABLISHED

mail# netstat -a -f inet -p tcp | grep "*.imap*"
tcp4       0      0  *.imaps                     *.*                   LISTEN
tcp4       0      0  *.imap                       *.*                   LISTEN

FreeBSD 5.4 with a few Outlook and KMail clients.

> /jon
>
> Dominic Marks said the following on 2005-04-26 16:11:
> >On Tuesday 26 April 2005 14:58, Jon wrote:
> >>Hi,
> >>
> >>Im using dovecote as my IMAP interface. However i do have a lot of imap
> >>instances. its only 7 user using the system as i get this. please advice.
> >
> >Having lots of processes running isn't automatically a bad thing, but you
> > do
> >
> >seem to have quite a lot of imap and imap-login processes, so:
> >>From a dovecot.conf on a server I run being used by about 7 people:
> >
> > (Comments are from dovecot-sample.conf)
> >
> ># Should each login be processed in it's own process (yes), or should one
> ># login process be allowed to process multiple connections (no)? Yes is
> > more # secure, espcially with SSL/TLS enabled. No is faster since there's
> > no need # to create processes all the time.
> >login_process_per_connection = no
> >
> >So if security is less of a concern than having many processes running,
> > you should set this to no.
> >
> ># Number of login processes to create. If login_process_per_user is
> ># yes, this is the number of extra processes waiting for users to log in.
> >login_processes_count = 1
> >
> >I set this low because I don't need the extra processes.
> >
> ># Maximum number of extra login processes to create. The extra process
> > count # usually stays at login_processes_count, but when multiple users
> > start # logging in at the same time more extra processes are created. To
> > prevent # fork-bombing we check only once in a second if new processes
> > should be # created - if all of them are used at the time, we double
> > their amount until # limit set by this setting is reached. This setting
> > is used only if # login_process_per_use is yes.
> >#login_max_processes_count = 128
> >
> >You might want to set this to something like 4?
> >
> ># Maximum number of connections allowed in login state. When this limit is
> ># reached, the oldest connections are dropped. If login_process_per_user
> ># is no, this is a per-process value, so the absolute maximum number of
> > users # logging in actually login_processes_count * max_logging_users.
> >#login_max_logging_users = 256
> >
> >Probably no need to worry about this.
> >
> >>1230 ?        S      0:00 imap-login
> >> 1309 ?        S      0:00 imap-login
> >
> > <snip>
> >
> >> 2387 ?        S      0:00 imap-login 3095 ?        S      0:00 imap
> >> 3096 ?        S      0:00 imap-login
> >>
> >>/jon
> >
> >Other things to think about:
> >
> >Are the mailboxes being accessed via Webmail?
> >What Mail application are your users using?
> >Have you checked what state the connections are in?
> >
> >HTH,

-- 
Dominic
GoodforBusiness.co.uk
I.T. Services for SMEs in the UK.