dovecot - Oct 2008 - "dovecot: Maximum number of mail processes exceeded"

At noon, I often get "dovecot: Maximum number of mail processes
exceeded"

I'm at my wits end, which parameter needs to be increased further?

# 1.1.3: /usr/local/etc/dovecot.conf
protocols: imap imaps pop3s
ssl_cert_file: /etc/ssl/certs/postamt.pem
ssl_key_file: /etc/ssl/private/postamt.key
disable_plaintext_auth: no
version_ignore: yes
login_dir: /usr/local/var/run/dovecot/login
login_executable(default): /usr/local/libexec/dovecot/imap-login
login_executable(imap): /usr/local/libexec/dovecot/imap-login
login_executable(pop3): /usr/local/libexec/dovecot/pop3-login
login_process_per_connection: no
login_greeting_capability(default): yes
login_greeting_capability(imap): yes
login_greeting_capability(pop3): no
login_processes_count: 32
login_max_processes_count: 2048
login_max_connections: 512
max_mail_processes: 1024
mail_max_userip_connections: 2048
verbose_proctitle: yes
mail_location: maildir:~/Maildir
fsync_disable: yes
maildir_copy_preserve_filename: yes
mail_drop_priv_before_exec: yes
mail_executable(default): /usr/local/sbin/imap_login_script
mail_executable(imap): /usr/local/sbin/imap_login_script
mail_executable(pop3): /usr/local/sbin/pop_login_script
mail_plugins(default): quota imap_quota trash mail_log fts fts_squat
mail_plugins(imap): quota imap_quota trash mail_log fts fts_squat
mail_plugins(pop3): quota mail_log
mail_plugin_dir(default): /usr/local/lib/dovecot/imap
mail_plugin_dir(imap): /usr/local/lib/dovecot/imap
mail_plugin_dir(pop3): /usr/local/lib/dovecot/pop3
mail_log_max_lines_per_sec: 0
imap_client_workarounds(default): outlook-idle netscape-eoh
imap_client_workarounds(imap): outlook-idle netscape-eoh
imap_client_workarounds(pop3): 
pop3_lock_session(default): no
pop3_lock_session(imap): no
pop3_lock_session(pop3): yes
pop3_uidl_format(default): %08Xu%08Xv
pop3_uidl_format(imap): %08Xu%08Xv
pop3_uidl_format(pop3): %v-%u
pop3_client_workarounds(default): 
pop3_client_workarounds(imap): 
pop3_client_workarounds(pop3): outlook-no-nuls oe-ns-eoh
namespace:
  type: private
  separator: .
  prefix: INBOX.
  inbox: yes
  list: yes
  subscriptions: yes
auth default:
  mechanisms: plain login
  cache_size: 64
  master_user_separator: *
  verbose: yes
  passdb:
    driver: passwd-file
    args: /usr/local/etc/dovecot.masterusers
    pass: yes
    master: yes
  passdb:
    driver: shadow
  passdb:
    driver: pam
    args: cache_key=%u dovecot
  userdb:
    driver: passwd
  socket:
    type: listen
    client:
      path: /var/spool/postfix/private/auth
      mode: 432
      user: postfix
      group: postfix
plugin:
  fts: squat
  quota: maildir
  quota_rule: Trash:storage=100M
  quota_warning: storage=90%% /usr/local/scripts/quota-warning 90
  quota_warning2: storage=95%% /usr/local/scripts/quota-warning 95
  quota_warning3: storage=99%% /usr/local/scripts/quota-warning 99
  trash: /usr/local/etc/dovecot-trash.conf

-- 
Ralf Hildebrandt (Ralf.Hildebrandt at charite.de)          snickebo at
charite.de
Postfix - Einrichtung, Betrieb und Wartung       Tel. +49 (0)30-450 570-155
http://www.arschkrebs.de                              I'm looking for a job
Vampireware /n/, a project, capable of sucking the lifeblood out of
anyone unfortunate enough to be assigned to it, which never actually
sees the light of day, but nonetheless refuses to die.

Hi Ralf,
> At noon, I often get "dovecot: Maximum number of mail processes
> exceeded"
> 
> I'm at my wits end, which parameter needs to be increased further?
You have to increase "max_mail_processes" as this code emits the error
message:

        if (mail_process_count == set->max_mail_processes) {
                i_error("Maximum number of mail processes exceeded");
                return MASTER_LOGIN_STATUS_INTERNAL_ERROR;
        }

[...]
> max_mail_processes: 1024
[...]

But the question is: how much user are accessing your server
simultaneously? Is it really more than 1024 or is mail_process_count wrong?
Your overpowered server is surely able to handle more than 1024 connections.

Heiko

Heiko Schlichting          Freie Universit?t Berlin
heiko at FU-Berlin.DE         Zentraleinrichtung f?r Datenverarbeitung (ZEDAT)
Telefon +49 30 838-54327   Fabeckstra?e 32
Telefax +49 30 838454327   14195 Berlin