Service unavailable, lots of idle dovecot-login processes

Wolfgang adminkram at tripelspark.de
Fri Feb 5 11:46:29 EET 2021


Hi,

Sorry, the problem is back! Not solved, again no change except that I
lowered the limits again and restarted dovecot. Here is what it looks like:

lsof -a -i4 -i6 -itcp | fgrep imap-logi | wc
9

--> There are 9 TCP connections to imap-login.

ps aux | fgrep imap-login | wc
81
ps aux | fgrep imap | wc
90

--> There are 90-81 = 9 IMAP worker processes (OK) and 81 imap-login
processes (not OK). Thunderbird cannot connect again.

ps auxf | fgrep dove
root     28118  0.0  0.0   4200  2752 ?        Ss   Feb03   0:02
/usr/sbin/dovecot -F
dovecot  28138  0.0  0.0   4176  2224 ?        S    Feb03   0:01  \_
dovecot/anvil
root     28139  0.0  0.0   4172  2436 ?        S    Feb03   0:00  \_
dovecot/log
root     28140  0.0  0.0   6764  4636 ?        S    Feb03   0:05  \_
dovecot/config
dovecot  28143  0.0  0.0   5360  3584 ?        S    Feb03   0:01  \_
dovecot/stats
dovenull 28206  0.0  0.0   8200  4652 ?        S    Feb03   0:02  \_
dovecot/imap-login
USER2    28207  0.0  0.0   6356  3988 ?        S    Feb03   0:02  \_
dovecot/imap
dovenull 28234  0.0  0.0   8200  4712 ?        S    Feb03   0:02  \_
dovecot/imap-login
USER1  28235  0.0  0.0   6356  2924 ?        S    Feb03   0:02  \_
dovecot/imap
dovenull 28275  0.0  0.0   8200  4716 ?        S    Feb03   0:02  \_
dovecot/imap-login
USER1  28276  0.0  0.0   9416  7308 ?        S    Feb03   0:03  \_
dovecot/imap
dovenull 19673  0.0  0.0   8212  6380 ?        S    Feb04   0:00  \_
dovecot/imap-login
USER3   19674  0.0  0.0  14220  7680 ?        S    Feb04   0:01  \_
dovecot/imap
dovenull 21688  0.0  0.0   8200  6416 ?        S    Feb04   0:01  \_
dovecot/imap-login
USER2    21690  0.0  0.0   9604  8504 ?        S    Feb04   0:01  \_
dovecot/imap
dovenull 22398  0.0  0.0   8200  6440 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 22400  0.0  0.0   8200  6384 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 22593  0.0  0.0   8200  6292 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 22595  0.0  0.0   8200  6312 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 22814  0.0  0.0   8200  6324 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 22816  0.0  0.0   8200  6312 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 23026  0.0  0.0   8200  6384 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 23028  0.0  0.0   8200  6340 ?        S    Feb04   0:00  \_
dovecot/imap-login
.......(skipped some lines of imap-login)........
dovenull 23179  0.0  0.0   8200  6412 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 23181  0.0  0.0   8200  6368 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 23421  0.0  0.0   8200  6284 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 23423  0.0  0.0   8200  6412 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 23611  0.0  0.0   8200  6380 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 23613  0.0  0.0   8200  6296 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 23797  0.0  0.0   8200  6464 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 23799  0.0  0.0   8200  6296 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 24029  0.0  0.0   8200  6300 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 24031  0.0  0.0   8200  6188 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 24205  0.0  0.0   8200  6340 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull 24207  0.0  0.0   8200  6320 ?        S    Feb04   0:00  \_
dovecot/imap-login
dovenull  5628  0.0  0.0   8212  6408 ?        S    08:59   0:00  \_
dovecot/imap-login
USER1   5629  0.0  0.0   7844  6460 ?        S    08:59   0:00  \_
dovecot/imap
optores   5630  0.0  0.0   6356  4444 ?        S    08:59   0:00  \_
dovecot/imap
USER1   5631  0.0  0.0   6372  4568 ?        S    08:59   0:00  \_
dovecot/imap
dovenull  6373  0.0  0.0   8200  6224 ?        S    09:43   0:00  \_
dovecot/imap-login
USER1   6375  0.0  0.0   7052  5900 ?        S    09:43   0:00  \_
dovecot/imap

The config is the same as last time except for this:

auth_worker_max_count = 100
default_process_limit = 80

Which should be more than enough.

Any ideas?
Wolfgang

On 2/3/21 8:19 PM, Wolfgang wrote:
> Hi,
> 
>> But as Aki said, doveconf -n is crucial, especially since you upgraded
> from an older version.
>>
> 
> Thank you for your response. Unfortunately, I missed the first e-mail a
> few days ago.
> 
> Interestingly it does no longer happen since a few days. We're seeing
> one IMAP and one IMAP-LOGIN process per connection now which is the
> expected behavior.
> 
> It's completely unclear to me why this does not longer happen now.
> 
> Anyway, here's the doveconf output in case you spot something.
> 
> Thank you,
> Wolfgang
> 
> # 2.3.4.1 (f79e8e7e4): /etc/dovecot/dovecot.conf
> # Pigeonhole version 0.5.4 ()
> # OS: Linux 4.19.0-11-amd64 x86_64 Debian 10.7
> # Hostname: static......
> auth_mechanisms = scram-sha-1 digest-md5 cram-md5 plain
> auth_worker_max_count = 300
> default_process_limit = 200
> first_valid_uid = 1000
> hostname = .......
> log_timestamp = "%Y-%m-%d %H:%M:%S "
> mail_location = maildir:~/Maildir
> mail_plugins = quota acl
> mail_privileged_group = mail
> mail_server_admin = postmaster at .......
> managesieve_notify_capability = mailto
> managesieve_sieve_capability = fileinto reject envelope
> encoded-character vacation subaddress comparator-i;ascii-numeric
> relational regex imap4flags copy include variables body enotify
> environment mailbox date index ihave duplicate mime foreverypart
> extracttext editheader
> namespace inbox {
>   inbox = yes
>   location =
>   mailbox Drafts {
>     special_use = \Drafts
>   }
>   mailbox Junk {
>     special_use = \Junk
>   }
>   mailbox Sent {
>     special_use = \Sent
>   }
>   mailbox "Sent Messages" {
>     special_use = \Sent
>   }
>   mailbox Trash {
>     special_use = \Trash
>   }
>   prefix =
>   separator = /
>   type = private
> }
> namespace zzzzz {
>   list = children
>   location = maildir:%%h/Maildir-xxx:INDEX=~/index_shared/%%u
>   prefix = shared/%%u/
>   separator = /
>   subscriptions = no
>   type = shared
> }
> passdb {
>   args = /etc/dovecot/shadow
>   driver = passwd-file
> }
> plugin {
>   acl = vfile
>   acl_shared_dict = file:/var/mail/shared-%d/shared-mailboxes
>   quota = maildir:User quota
>   quota_rule = *:storage=1G
>   quota_warning = storage=90%% quota-warning 90 %u
>   sieve = file:~/sieve;active=~/dovecot.sieve
>   sieve_extensions = +editheader
> }
> postmaster_address = postmaster at xxxxxxx.de
> protocols = " imap sieve sieve"
> service auth-worker {
>   chroot = yes
>   user = $default_internal_user
> }
> service auth {
>   unix_listener /var/spool/postfix/private/auth {
>     group = postfix
>     mode = 0660
>     user = postfix
>   }
> }
> service imap-login {
>   vsz_limit = 64 M
> }
> service managesieve-login {
>   inet_listener sieve {
>     port = 4190
>   }
>   inet_listener sieve_deprecated {
>     port = 2000
>   }
> }
> ssl_cert = </etc/letsencrypt/live/..../fullchain.pem
> ssl_client_ca_dir = /etc/ssl/certs
> ssl_dh = # hidden, use -P to show it
> ssl_key = # hidden, use -P to show it
> userdb {
>   args = /etc/dovecot/passwd
>   default_fields = quota_rule=*:storage=1G
>   driver = passwd-file
> }
> protocol lda {
>   mail_plugins = quota acl sieve
> }
> protocol imap {
>   mail_max_userip_connections = 32
>   mail_plugins = quota acl imap_quota imap_acl
> }
> 


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