dovecot - Nov 2010 - iPhone leaves imap process active

A quick search of the archives didn't reveal a fix, so I thought I'd ask
the list.  I was running Dovecot 2.0.2, and noticed a lot of CPU being used up. 
I discovered a number of IMAP processes burning a lot of cycles, when no
connections should have been active.  I traced this to the iPhone leaving the
IMAP connection apparently active.

I just upgraded to Dovecot 2.0.7, and I'm still seeing connections left
active, but haven't seen the high CPU usage yet, but I've only been
running 2.0.7 for about 30 minutes.

I tried adding kill_idle to the IMAP config, but that doesn't seem to have
helped.  Turning off the iPhone does kill the connection, so I know that the
iPhone is really keeping the connection alive, but if I can find a way to keep
these connections down, I'd really rather have that ability.

Here's my config:


wrights-Mac-mini:/Users/transmit wright$ doveconf -n
# 2.0.7: /usr/local/etc/dovecot/dovecot.conf
# OS: Darwin 10.4.0 i386  hfs
auth_mechanisms = plain login cram-md5
default_internal_user = _dovecot
disable_plaintext_auth = no
first_valid_gid = 27
first_valid_uid = 27
last_valid_gid = 27
last_valid_uid = 27
mail_gid = 27
mail_location = maildir:/var/mail/vhosts/%d/%n
mail_privileged_group = postfix
mail_uid = 27
namespace {
  inbox = yes
  location = 
  prefix = 
  type = private
}
passdb {
  args = /usr/local/etc/dovecot-mysql.conf
  driver = sql
}
protocols = imap pop3
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0660
    user = postfix
  }
  user = root
}
service imap-login {
  process_limit = 64
}
service imap {
  idle_kill = 150 secs
  process_limit = 128
}
service pop3-login {
  process_limit = 64
}
service pop3 {
  process_limit = 128
}
ssl = no
userdb {
  args = /usr/local/etc/dovecot-mysql.conf
  driver = sql
}
protocol lda {
  postmaster_address = postmaster at example.com
}
wrights-Mac-mini:/Users/transmit wright$

On 26.11.2010, at 4.16, Jim wrote:
> A quick search of the archives didn't reveal a fix, so I thought
I'd ask the list.  I was running Dovecot 2.0.2, and noticed a lot of CPU
being used up.  I discovered a number of IMAP processes burning a lot of cycles,
when no connections should have been active.  I traced this to the iPhone
leaving the IMAP connection apparently active.
> 
> I just upgraded to Dovecot 2.0.7, and I'm still seeing connections left
active, but haven't seen the high CPU usage yet, but I've only been
running 2.0.7 for about 30 minutes.
> 
> I tried adding kill_idle to the IMAP config, but that doesn't seem to
have helped.  Turning off the iPhone does kill the connection, so I know that
the iPhone is really keeping the connection alive, but if I can find a way to
keep these connections down, I'd really rather have that ability.
IMAP clients generally leave connections open for a long time. I've had an
IMAP connection open for weeks. So I think all works as intended, although I
don't know specifically how iPhone should work.

Perhaps in some distant future Dovecot could move all such idling connections to
be handled by a single "idle process" to free some memory.