dovecot - Feb 2021 - Service unavailable, lots of idle dovecot-login processes

On 02 Feb 2021, at 05:59, Wolfgang <adminkram at tripelspark.de>
wrote:
> hen listing TCP connections via lsof, there are only around 30
> connections open to IMAP and we have exactly the same amount of
> dovecot/imap processes. These connections are held by 30
> dovecot/imap-login processes.
> 
> The other 70 dovecot/imap-login processes seem to do nothing. They're
> all sitting in "epoll_wait(14," according to strace but don't
have TCP
> connections open.
Have you tried reducing the number from 100 to, say, 30?

But as Aki said, doveconf -n is crucial, especially since you upgraded from an
older version.

-- 
I draw the line at 7 unreturned phone calls.

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
}