dovecot - Jan 2020 - Upgrade 2.2.27 to 2.3.9.2: master(imap): net_connect_unix(imap) failed: Resource temporarily unavailable

As a workaround for the titular issue, I have tried enabling the 
"imap-hibernate" service on a couple of servers to reduce the number
of
running imap processes.

Since ~50-60% of clients are in IDLE at any one time, this allows us to 
reduce the number of running imap processes to less than half of what it 
was.

After this I have yet to see the "net_connect_unix(imap) failed"
errors
on these servers, however instead we are now instead seeing a few of these:

   imap([redacted])<30266><[redacted]>: Error: imap-master: Failed
to
import client state: Mailbox INBOX: Couldn't get recently expunged UIDs 
(uidnext=13479 highest_modseq=1716)

and

   imap([redacted])<20055><[redacted]>: Error: imap-master: Failed
to
import client state: Mailbox INBOX: Couldn't send flag changes
   imap([redacted])<20055><[redacted]>: NOTIFY failed in the middle
of
FETCH reply in=0 out=0 deleted=0 expunged=0 trashed=0 hdr_count=0 
hdr_bytes=0 body_count=0 body_bytes=0

The former I suspect may be related to our NFS-backed store and 
simultaneous access from different, since many of the errors are 
accompanied by other corruption related errors:

   imap([redacted])<30266><[redacted]>: Error: Mailbox INBOX:
vsize-hdr
has invalid size: 36

This whole upgrade is part of a migration to a director-backed system, 
because we are seeing a too large amount of corruption errors 
(locking/indexes, etc) assumed to be caused by NFS.

Once we introduce the director cluster in front, these errors should 
hopefully be strongly reduced. :-)

-- 
Eirik

On 08/01/2020 15:14, Eirik Rye wrote:
> With proctitles below.
> 
> Strangely, Dovecot is reporting 12679 imap-login sockets in
"pre-login"
> state, which is about 50% more than there are active TCP connections to 
> the server (8271, of which 7546 are in "imap-login" process
according to
> `ss -tp`).
> 
> On another server, not currently experiencing this issue, the number of 
> TCP sockets appears to more closely match the number of imap-login 
> sockets used (either in pre-login or TLS proxing).
> 
> imap:~# ps -f --ppid `pidof dovecot` | egrep -v "dovecot/(imap|pop3)
"
> UID??????? PID? PPID? C STIME TTY????????? TIME CMD
> dovenull? 5262? 5260? 0 11:48 ???????? 00:00:00 dovecot/pop3-login
> dovenull? 5263? 5260? 2 11:48 ???????? 00:03:53 dovecot/imap-login [724 
> pre-login + 113 TLS proxies]
> dovecot?? 5264? 5260? 0 11:48 ???????? 00:01:15 dovecot/anvil [21 
> connections]
> root????? 5265? 5260? 1 11:48 ???????? 00:02:18 dovecot/log
> dovenull? 5266? 5260? 0 11:48 ???????? 00:00:00 dovecot/pop3-login
> dovenull? 5267? 5260? 0 11:48 ???????? 00:00:00 dovecot/pop3-login
> dovenull? 5268? 5260? 0 11:48 ???????? 00:00:00 dovecot/pop3-login
> dovenull? 5269? 5260 20 11:48 ???????? 00:35:34 dovecot/imap-login [1073 
> pre-login + 1199 TLS proxies]
> dovenull? 5270? 5260? 1 11:48 ???????? 00:02:25 dovecot/imap-login [615 
> pre-login + 67 TLS proxies]
> dovenull? 5271? 5260? 0 11:48 ???????? 00:01:39 dovecot/imap-login [489 
> pre-login + 44 TLS proxies]
> dovenull? 5272? 5260 14 11:48 ???????? 00:24:44 dovecot/imap-login [938 
> pre-login + 720 TLS proxies]
> dovenull? 5273? 5260? 6 11:48 ???????? 00:10:30 dovecot/imap-login [845 
> pre-login + 242 TLS proxies]
> dovenull? 5274? 5260? 4 11:48 ???????? 00:06:54 dovecot/imap-login [817 
> pre-login + 209 TLS proxies]
> dovenull? 5275? 5260? 0 11:48 ???????? 00:01:23 dovecot/imap-login [445 
> pre-login + 36 TLS proxies]
> dovenull? 5276? 5260 25 11:48 ???????? 00:43:14 dovecot/imap-login [1064 
> pre-login + 1434 TLS proxies]
> dovenull? 5277? 5260? 1 11:48 ???????? 00:02:19 dovecot/imap-login [523 
> pre-login + 58 TLS proxies]
> dovenull? 5278? 5260? 9 11:48 ???????? 00:16:19 dovecot/imap-login [937 
> pre-login + 462 TLS proxies]
> dovenull? 5279? 5260 19 11:48 ???????? 00:33:24 dovecot/imap-login [937 
> pre-login + 823 TLS proxies]
> dovenull? 5280? 5260? 1 11:48 ???????? 00:03:04 dovecot/imap-login [655 
> pre-login + 92 TLS proxies]
> dovenull? 5281? 5260 26 11:48 ???????? 00:45:20 dovecot/imap-login [969 
> pre-login + 1450 TLS proxies]
> dovenull? 5282? 5260? 6 11:48 ???????? 00:10:55 dovecot/imap-login [917 
> pre-login + 303 TLS proxies]
> dovenull? 5283? 5260? 4 11:48 ???????? 00:08:36 dovecot/imap-login [731 
> pre-login + 128 TLS proxies]
> root????? 5284? 5260? 2 11:48 ???????? 00:03:55 dovecot/config
> dovecot?? 5285? 5260? 1 11:48 ???????? 00:02:19 dovecot/stats [7968 
> connections]
> dovecot?? 5286? 5260? 3 11:48 ???????? 00:05:53 dovecot/auth [138 wait, 
> 0 passdb, 0 userdb]
> 528246?? 10322? 5260? 0 14:36 ???????? 00:00:00 [imap]
> root???? 16688? 5260? 0 14:40 ???????? 00:00:00 dovecot/imap
> imap02:~# doveadm process status | grep "^imap-login " | awk
"{sum +=
> 2500-\$3} END {print sum}"
> 20081
> imap:~# ps -f --ppid `pidof dovecot` | grep "dovecot/imap " | wc
-l
> 7937
> imap:~# doveadm process status | grep "^imap " | wc -l
> 7937
> imap:~# ss -ntp "( sport = :143 or sport = :993 )" | grep
"\"imap\"" |
> wc -l
> 559
> imap:~# ss -ntp "( sport = :143 or sport = :993 )" | grep 
> "\"imap-login\"" | wc -l
> 7546
> imap:~# ss -ntp "( sport = :143 or sport = :993 )" | wc -l
> 8271
> 
> On 08/01/2020 11:33, Eirik Rye wrote:
>> On 08/01/2020 11:09, Aki Tuomi wrote:
>>> Can you enable 'verbose_proctitle=yes' and maybe compare
with ss -tp
>>> output?
>>
>> Thanks for the response!
>>
>> What exactly did you want to compare? `ss -tp` does not appear to show 
>> cmdline/process title. I enabled it for one server, but will have to 
>> wait for users to reconnect and for the issue to reappear there.
>>
>> In the meantime, on another server experiencing the same issue at this 
>> moment (same configuration), but no proctitles:
>>
>> root at imap03:~# doveadm process status | grep "^imap " | wc
-l
>> 7564
>> root at imap03:~# ps aux | grep "dovecot/imap$" | wc -l
>> 7570
>> root at imap03:~# ss -tp | grep '"imap-login"' | wc
-l
>> 8009
>> root at imap03:~# ss -tp | grep '"imap"' | wc -l
>> 536
>> root at imap03:~# ss -nt "( sport = :143 or sport = :993 )" |
wc -l
>> 8739
>> root at imap03:~# doveadm who -1 | wc -l
>> 7581
>>
>> The `ss -tp` output appears normal (e.g. 8009+536 ~= 8739).
>>
> 
>

Uh. It's not actually supported to access same user concurrently from two
servers even if you are using NFS. It will cause problems. You should use
dovecot director or some other arrangement to make sure this does not happen.

Aki
> On 09/01/2020 16:56 Eirik Rye <rye at domeneshop.no> wrote:
> 
>  
> As a workaround for the titular issue, I have tried enabling the 
> "imap-hibernate" service on a couple of servers to reduce the
number of
> running imap processes.
> 
> Since ~50-60% of clients are in IDLE at any one time, this allows us to 
> reduce the number of running imap processes to less than half of what it 
> was.
> 
> After this I have yet to see the "net_connect_unix(imap) failed"
errors
> on these servers, however instead we are now instead seeing a few of these:
> 
>    imap([redacted])<30266><[redacted]>: Error: imap-master:
Failed to
> import client state: Mailbox INBOX: Couldn't get recently expunged UIDs
> (uidnext=13479 highest_modseq=1716)
> 
> and
> 
>    imap([redacted])<20055><[redacted]>: Error: imap-master:
Failed to
> import client state: Mailbox INBOX: Couldn't send flag changes
>    imap([redacted])<20055><[redacted]>: NOTIFY failed in the
middle of
> FETCH reply in=0 out=0 deleted=0 expunged=0 trashed=0 hdr_count=0 
> hdr_bytes=0 body_count=0 body_bytes=0
> 
> The former I suspect may be related to our NFS-backed store and 
> simultaneous access from different, since many of the errors are 
> accompanied by other corruption related errors:
> 
>    imap([redacted])<30266><[redacted]>: Error: Mailbox INBOX:
vsize-hdr
> has invalid size: 36
> 
> This whole upgrade is part of a migration to a director-backed system, 
> because we are seeing a too large amount of corruption errors 
> (locking/indexes, etc) assumed to be caused by NFS.
> 
> Once we introduce the director cluster in front, these errors should 
> hopefully be strongly reduced. :-)
> 
> -- 
> Eirik
> 
> On 08/01/2020 15:14, Eirik Rye wrote:
> > With proctitles below.
> > 
> > Strangely, Dovecot is reporting 12679 imap-login sockets in
"pre-login"
> > state, which is about 50% more than there are active TCP connections
to
> > the server (8271, of which 7546 are in "imap-login" process
according to
> > `ss -tp`).
> > 
> > On another server, not currently experiencing this issue, the number
of
> > TCP sockets appears to more closely match the number of imap-login 
> > sockets used (either in pre-login or TLS proxing).
> > 
> > imap:~# ps -f --ppid `pidof dovecot` | egrep -v
"dovecot/(imap|pop3) "
> > UID??????? PID? PPID? C STIME TTY????????? TIME CMD
> > dovenull? 5262? 5260? 0 11:48 ???????? 00:00:00 dovecot/pop3-login
> > dovenull? 5263? 5260? 2 11:48 ???????? 00:03:53 dovecot/imap-login
[724
> > pre-login + 113 TLS proxies]
> > dovecot?? 5264? 5260? 0 11:48 ???????? 00:01:15 dovecot/anvil [21 
> > connections]
> > root????? 5265? 5260? 1 11:48 ???????? 00:02:18 dovecot/log
> > dovenull? 5266? 5260? 0 11:48 ???????? 00:00:00 dovecot/pop3-login
> > dovenull? 5267? 5260? 0 11:48 ???????? 00:00:00 dovecot/pop3-login
> > dovenull? 5268? 5260? 0 11:48 ???????? 00:00:00 dovecot/pop3-login
> > dovenull? 5269? 5260 20 11:48 ???????? 00:35:34 dovecot/imap-login
[1073
> > pre-login + 1199 TLS proxies]
> > dovenull? 5270? 5260? 1 11:48 ???????? 00:02:25 dovecot/imap-login
[615
> > pre-login + 67 TLS proxies]
> > dovenull? 5271? 5260? 0 11:48 ???????? 00:01:39 dovecot/imap-login
[489
> > pre-login + 44 TLS proxies]
> > dovenull? 5272? 5260 14 11:48 ???????? 00:24:44 dovecot/imap-login
[938
> > pre-login + 720 TLS proxies]
> > dovenull? 5273? 5260? 6 11:48 ???????? 00:10:30 dovecot/imap-login
[845
> > pre-login + 242 TLS proxies]
> > dovenull? 5274? 5260? 4 11:48 ???????? 00:06:54 dovecot/imap-login
[817
> > pre-login + 209 TLS proxies]
> > dovenull? 5275? 5260? 0 11:48 ???????? 00:01:23 dovecot/imap-login
[445
> > pre-login + 36 TLS proxies]
> > dovenull? 5276? 5260 25 11:48 ???????? 00:43:14 dovecot/imap-login
[1064
> > pre-login + 1434 TLS proxies]
> > dovenull? 5277? 5260? 1 11:48 ???????? 00:02:19 dovecot/imap-login
[523
> > pre-login + 58 TLS proxies]
> > dovenull? 5278? 5260? 9 11:48 ???????? 00:16:19 dovecot/imap-login
[937
> > pre-login + 462 TLS proxies]
> > dovenull? 5279? 5260 19 11:48 ???????? 00:33:24 dovecot/imap-login
[937
> > pre-login + 823 TLS proxies]
> > dovenull? 5280? 5260? 1 11:48 ???????? 00:03:04 dovecot/imap-login
[655
> > pre-login + 92 TLS proxies]
> > dovenull? 5281? 5260 26 11:48 ???????? 00:45:20 dovecot/imap-login
[969
> > pre-login + 1450 TLS proxies]
> > dovenull? 5282? 5260? 6 11:48 ???????? 00:10:55 dovecot/imap-login
[917
> > pre-login + 303 TLS proxies]
> > dovenull? 5283? 5260? 4 11:48 ???????? 00:08:36 dovecot/imap-login
[731
> > pre-login + 128 TLS proxies]
> > root????? 5284? 5260? 2 11:48 ???????? 00:03:55 dovecot/config
> > dovecot?? 5285? 5260? 1 11:48 ???????? 00:02:19 dovecot/stats [7968 
> > connections]
> > dovecot?? 5286? 5260? 3 11:48 ???????? 00:05:53 dovecot/auth [138
wait,
> > 0 passdb, 0 userdb]
> > 528246?? 10322? 5260? 0 14:36 ???????? 00:00:00 [imap]
> > root???? 16688? 5260? 0 14:40 ???????? 00:00:00 dovecot/imap
> > imap02:~# doveadm process status | grep "^imap-login " | awk
"{sum +=
> > 2500-\$3} END {print sum}"
> > 20081
> > imap:~# ps -f --ppid `pidof dovecot` | grep "dovecot/imap "
| wc -l
> > 7937
> > imap:~# doveadm process status | grep "^imap " | wc -l
> > 7937
> > imap:~# ss -ntp "( sport = :143 or sport = :993 )" | grep
"\"imap\"" |
> > wc -l
> > 559
> > imap:~# ss -ntp "( sport = :143 or sport = :993 )" | grep 
> > "\"imap-login\"" | wc -l
> > 7546
> > imap:~# ss -ntp "( sport = :143 or sport = :993 )" | wc -l
> > 8271
> > 
> > On 08/01/2020 11:33, Eirik Rye wrote:
> >> On 08/01/2020 11:09, Aki Tuomi wrote:
> >>> Can you enable 'verbose_proctitle=yes' and maybe
compare with ss -tp
> >>> output?
> >>
> >> Thanks for the response!
> >>
> >> What exactly did you want to compare? `ss -tp` does not appear to
show
> >> cmdline/process title. I enabled it for one server, but will have
to
> >> wait for users to reconnect and for the issue to reappear there.
> >>
> >> In the meantime, on another server experiencing the same issue at
this
> >> moment (same configuration), but no proctitles:
> >>
> >> root at imap03:~# doveadm process status | grep "^imap "
| wc -l
> >> 7564
> >> root at imap03:~# ps aux | grep "dovecot/imap$" | wc -l
> >> 7570
> >> root at imap03:~# ss -tp | grep '"imap-login"' |
wc -l
> >> 8009
> >> root at imap03:~# ss -tp | grep '"imap"' | wc -l
> >> 536
> >> root at imap03:~# ss -nt "( sport = :143 or sport = :993
)" | wc -l
> >> 8739
> >> root at imap03:~# doveadm who -1 | wc -l
> >> 7581
> >>
> >> The `ss -tp` output appears normal (e.g. 8009+536 ~= 8739).
> >>
> > 
> >

Yes, I realize this. That is why we are introducing the directors to the 
cluster. We are also working on doing Dovecot LDA/LMTP delivery, to 
improve Dovecot's ability to react to new messages. Currently we are 
dropping email directly into the Maildir through other facilities, which 
works -fine-.

I realize however that IDLE is most likely not working properly with 
"imap-hibernate" in our current setup. I assume the "imap"
service is
normally responsible for monitoring the user's mailbox for changes done 
outside Dovecot?

Am I correct in my assumption that email must be delivered using 
LMTP/LDA from the same server in order for IDLE in imap-hibernate to 
work properly? Setting up a separate Dovecot instance purely for 
LDA/LMTP will not work, as the imap-hibernate process will not be 
notified of user mailbox activity in that case?

--
- Eirik

Den 09.01.2020 15:59, skrev Aki Tuomi:
> Uh. It's not actually supported to access same user concurrently from
two servers even if you are using NFS. It will cause problems. You should use
dovecot director or some other arrangement to make sure this does not happen.
> 
> Aki
> 
>> On 09/01/2020 16:56 Eirik Rye <rye at domeneshop.no> wrote:
>>
>>   
>> As a workaround for the titular issue, I have tried enabling the
>> "imap-hibernate" service on a couple of servers to reduce the
number of
>> running imap processes.
>>
>> Since ~50-60% of clients are in IDLE at any one time, this allows us to
>> reduce the number of running imap processes to less than half of what
it
>> was.
>>
>> After this I have yet to see the "net_connect_unix(imap)
failed" errors
>> on these servers, however instead we are now instead seeing a few of
these:
>>
>>     imap([redacted])<30266><[redacted]>: Error:
imap-master: Failed to
>> import client state: Mailbox INBOX: Couldn't get recently expunged
UIDs
>> (uidnext=13479 highest_modseq=1716)
>>
>> and
>>
>>     imap([redacted])<20055><[redacted]>: Error:
imap-master: Failed to
>> import client state: Mailbox INBOX: Couldn't send flag changes
>>     imap([redacted])<20055><[redacted]>: NOTIFY failed in
the middle of
>> FETCH reply in=0 out=0 deleted=0 expunged=0 trashed=0 hdr_count=0
>> hdr_bytes=0 body_count=0 body_bytes=0
>>
>> The former I suspect may be related to our NFS-backed store and
>> simultaneous access from different, since many of the errors are
>> accompanied by other corruption related errors:
>>
>>     imap([redacted])<30266><[redacted]>: Error: Mailbox
INBOX: vsize-hdr
>> has invalid size: 36
>>
>> This whole upgrade is part of a migration to a director-backed system,
>> because we are seeing a too large amount of corruption errors
>> (locking/indexes, etc) assumed to be caused by NFS.
>>
>> Once we introduce the director cluster in front, these errors should
>> hopefully be strongly reduced. :-)
>>
>> -- 
>> Eirik
>>
>> On 08/01/2020 15:14, Eirik Rye wrote:
>>> With proctitles below.
>>>
>>> Strangely, Dovecot is reporting 12679 imap-login sockets in
"pre-login"
>>> state, which is about 50% more than there are active TCP
connections to
>>> the server (8271, of which 7546 are in "imap-login"
process according to
>>> `ss -tp`).
>>>
>>> On another server, not currently experiencing this issue, the
number of
>>> TCP sockets appears to more closely match the number of imap-login
>>> sockets used (either in pre-login or TLS proxing).
>>>
>>> imap:~# ps -f --ppid `pidof dovecot` | egrep -v
"dovecot/(imap|pop3) "
>>> UID??????? PID? PPID? C STIME TTY????????? TIME CMD
>>> dovenull? 5262? 5260? 0 11:48 ???????? 00:00:00 dovecot/pop3-login
>>> dovenull? 5263? 5260? 2 11:48 ???????? 00:03:53 dovecot/imap-login
[724
>>> pre-login + 113 TLS proxies]
>>> dovecot?? 5264? 5260? 0 11:48 ???????? 00:01:15 dovecot/anvil [21
>>> connections]
>>> root????? 5265? 5260? 1 11:48 ???????? 00:02:18 dovecot/log
>>> dovenull? 5266? 5260? 0 11:48 ???????? 00:00:00 dovecot/pop3-login
>>> dovenull? 5267? 5260? 0 11:48 ???????? 00:00:00 dovecot/pop3-login
>>> dovenull? 5268? 5260? 0 11:48 ???????? 00:00:00 dovecot/pop3-login
>>> dovenull? 5269? 5260 20 11:48 ???????? 00:35:34 dovecot/imap-login
[1073
>>> pre-login + 1199 TLS proxies]
>>> dovenull? 5270? 5260? 1 11:48 ???????? 00:02:25 dovecot/imap-login
[615
>>> pre-login + 67 TLS proxies]
>>> dovenull? 5271? 5260? 0 11:48 ???????? 00:01:39 dovecot/imap-login
[489
>>> pre-login + 44 TLS proxies]
>>> dovenull? 5272? 5260 14 11:48 ???????? 00:24:44 dovecot/imap-login
[938
>>> pre-login + 720 TLS proxies]
>>> dovenull? 5273? 5260? 6 11:48 ???????? 00:10:30 dovecot/imap-login
[845
>>> pre-login + 242 TLS proxies]
>>> dovenull? 5274? 5260? 4 11:48 ???????? 00:06:54 dovecot/imap-login
[817
>>> pre-login + 209 TLS proxies]
>>> dovenull? 5275? 5260? 0 11:48 ???????? 00:01:23 dovecot/imap-login
[445
>>> pre-login + 36 TLS proxies]
>>> dovenull? 5276? 5260 25 11:48 ???????? 00:43:14 dovecot/imap-login
[1064
>>> pre-login + 1434 TLS proxies]
>>> dovenull? 5277? 5260? 1 11:48 ???????? 00:02:19 dovecot/imap-login
[523
>>> pre-login + 58 TLS proxies]
>>> dovenull? 5278? 5260? 9 11:48 ???????? 00:16:19 dovecot/imap-login
[937
>>> pre-login + 462 TLS proxies]
>>> dovenull? 5279? 5260 19 11:48 ???????? 00:33:24 dovecot/imap-login
[937
>>> pre-login + 823 TLS proxies]
>>> dovenull? 5280? 5260? 1 11:48 ???????? 00:03:04 dovecot/imap-login
[655
>>> pre-login + 92 TLS proxies]
>>> dovenull? 5281? 5260 26 11:48 ???????? 00:45:20 dovecot/imap-login
[969
>>> pre-login + 1450 TLS proxies]
>>> dovenull? 5282? 5260? 6 11:48 ???????? 00:10:55 dovecot/imap-login
[917
>>> pre-login + 303 TLS proxies]
>>> dovenull? 5283? 5260? 4 11:48 ???????? 00:08:36 dovecot/imap-login
[731
>>> pre-login + 128 TLS proxies]
>>> root????? 5284? 5260? 2 11:48 ???????? 00:03:55 dovecot/config
>>> dovecot?? 5285? 5260? 1 11:48 ???????? 00:02:19 dovecot/stats [7968
>>> connections]
>>> dovecot?? 5286? 5260? 3 11:48 ???????? 00:05:53 dovecot/auth [138
wait,
>>> 0 passdb, 0 userdb]
>>> 528246?? 10322? 5260? 0 14:36 ???????? 00:00:00 [imap]
>>> root???? 16688? 5260? 0 14:40 ???????? 00:00:00 dovecot/imap
>>> imap02:~# doveadm process status | grep "^imap-login " |
awk "{sum +>>> 2500-\$3} END {print sum}"
>>> 20081
>>> imap:~# ps -f --ppid `pidof dovecot` | grep "dovecot/imap
" | wc -l
>>> 7937
>>> imap:~# doveadm process status | grep "^imap " | wc -l
>>> 7937
>>> imap:~# ss -ntp "( sport = :143 or sport = :993 )" | grep
"\"imap\"" |
>>> wc -l
>>> 559
>>> imap:~# ss -ntp "( sport = :143 or sport = :993 )" | grep
>>> "\"imap-login\"" | wc -l
>>> 7546
>>> imap:~# ss -ntp "( sport = :143 or sport = :993 )" | wc
-l
>>> 8271
>>>
>>> On 08/01/2020 11:33, Eirik Rye wrote:
>>>> On 08/01/2020 11:09, Aki Tuomi wrote:
>>>>> Can you enable 'verbose_proctitle=yes' and maybe
compare with ss -tp
>>>>> output?
>>>>
>>>> Thanks for the response!
>>>>
>>>> What exactly did you want to compare? `ss -tp` does not appear
to show
>>>> cmdline/process title. I enabled it for one server, but will
have to
>>>> wait for users to reconnect and for the issue to reappear
there.
>>>>
>>>> In the meantime, on another server experiencing the same issue
at this
>>>> moment (same configuration), but no proctitles:
>>>>
>>>> root at imap03:~# doveadm process status | grep "^imap
" | wc -l
>>>> 7564
>>>> root at imap03:~# ps aux | grep "dovecot/imap$" | wc
-l
>>>> 7570
>>>> root at imap03:~# ss -tp | grep
'"imap-login"' | wc -l
>>>> 8009
>>>> root at imap03:~# ss -tp | grep '"imap"' | wc
-l
>>>> 536
>>>> root at imap03:~# ss -nt "( sport = :143 or sport = :993
)" | wc -l
>>>> 8739
>>>> root at imap03:~# doveadm who -1 | wc -l
>>>> 7581
>>>>
>>>> The `ss -tp` output appears normal (e.g. 8009+536 ~= 8739).
>>>>
>>>
>>>
>