dovecot - May 2017 - [BUG] doveadm kick doesn't play well with hibernate

Hello,

Dovecot 2.2.27 (Debian Jessie backports).

When issuing a "doveadm kick" for a specific user I was greeted by:
---
"warning: other connections would also be kicked from following
users:"
---
and a list of 22odd thousand users.

As it turns out, kick wants to smack the hibernation proces(ses) that
have hibernated sessions for this user, obviously the wrong approach here.

If there's doveadm command to wake up and thus un-hibernate sessions for a
specific user this could be used as a workaround but a quick glance
suggest no such thing. 

This functionality is absolutely crucial for us as we need this for our
custom mailbox migration functionality.

If there's no workaround or fix within 2 months I'll be forced to
disable
hibernation again (with a heavy heart).

Regards,

Christian
-- 
Christian Balzer        Network/Systems Engineer                
chibi at gol.com   	Global OnLine Japan/Rakuten Communications
http://www.gol.com/

On 12 May 2017, at 5.14, Christian Balzer <chibi at gol.com>
wrote:
> 
> 
> Hello,
> 
> Dovecot 2.2.27 (Debian Jessie backports).
> 
> When issuing a "doveadm kick" for a specific user I was greeted
by:
> ---
> "warning: other connections would also be kicked from following
users:"
> ---
> and a list of 22odd thousand users.
> 
> As it turns out, kick wants to smack the hibernation proces(ses) that
> have hibernated sessions for this user, obviously the wrong approach here.
Kicking in backends works by sending a signal to the mail processes. It would be
nice to support other ways also, but that would require larger changes.
> If there's doveadm command to wake up and thus un-hibernate sessions
for a
> specific user this could be used as a workaround but a quick glance
> suggest no such thing. 
If you change the dovecot.index.log of any of the folders where the user is
IDLEing, that'd do it. I think just find /user 'dovecot.index.log' |
xargs touch would work.
> This functionality is absolutely crucial for us as we need this for our
> custom mailbox migration functionality.
> 
> If there's no workaround or fix within 2 months I'll be forced to
disable
> hibernation again (with a heavy heart).
How about doveadm director kick / doveadm proxy kick?

On Sun, 14 May 2017 23:34:39 +0300 Timo Sirainen wrote:
> On 12 May 2017, at 5.14, Christian Balzer <chibi at gol.com> wrote:
> > 
> > 
> > Hello,
> > 
> > Dovecot 2.2.27 (Debian Jessie backports).
> > 
> > When issuing a "doveadm kick" for a specific user I was
greeted by:
> > ---
> > "warning: other connections would also be kicked from following
users:"
> > ---
> > and a list of 22odd thousand users.
> > 
> > As it turns out, kick wants to smack the hibernation proces(ses) that
> > have hibernated sessions for this user, obviously the wrong approach
here.
> 
> Kicking in backends works by sending a signal to the mail processes. It
would be nice to support other ways also, but that would require larger changes.
> 
It's probably something you'll need to address sooner or later, given
that
I'm pretty sure that kick isn't the only thing assuming (wrongly) that
there's just one user per mail process. 
> > If there's doveadm command to wake up and thus un-hibernate
sessions for a
> > specific user this could be used as a workaround but a quick glance
> > suggest no such thing.   
> 
> If you change the dovecot.index.log of any of the folders where the user is
IDLEing, that'd do it. I think just find /user 'dovecot.index.log' |
xargs touch would work.
> 
That doesn't work for me at all.

Before and after touching the dovecot.index.log files:
---
# ps aux |grep chibi
mail      884727  0.0  0.0  24360  9176 ?        S    May14   0:00 dovecot/imap
[chibi at notgol.com xxx.xxx.7.126 IDLE]

# doveadm who |grep chibi
username           # proto (pids)                       (ips)
chibi at notgol.com   8 imap (884727 877825 119157)       (xxx.xxx.7.126
xxx.xxx.0.144 xxx.xxx.244.134)

# ps aux |grep hibernate
dovecot   119157  0.3  0.0  63448 56372 ?        S    Apr01 247:20
dovecot/imap-hibernate [16361 connections]
dovecot   877825  0.3  0.0  61776 54628 ?        S    Apr23 115:39
dovecot/imap-hibernate [10098 connections]
---

Note that I have "maildir_very_dirty_syncs = yes" set, but that
shouldn't
cause this based on the comment in the config blob. 
> > This functionality is absolutely crucial for us as we need this for
our
> > custom mailbox migration functionality.
> > 
> > If there's no workaround or fix within 2 months I'll be forced
to disable
> > hibernation again (with a heavy heart).  
> 
> How about doveadm director kick / doveadm proxy kick?
> 
Just proxy here. 
While that would work, it would require of course new code connecting to
the proxies (maintain a list as well) in sequence. 
Something that doesn't scale too well, since we aim to keep the mailboxes
in a locked state for as short as possible.

OTOH if the "waking up" part above can't be made to work, I guess
this is
at least a way forward for the time being. 

Christian
-- 
Christian Balzer        Network/Systems Engineer                
chibi at gol.com   	Global OnLine Japan/Rakuten Communications
http://www.gol.com/