Ubuntu Manpage: master - Postfix master process

Provided by: postfix_2.11.0-1ubuntu1.2_amd64

NAME

       master - Postfix master process

SYNOPSIS

       master [-Ddtvw] [-c config_dir] [-e exit_time]

DESCRIPTION

The master(8) daemon is the resident process that runs Postfix daemons on demand: daemons
to send or receive messages via the network, daemons to deliver mail locally, etc. These
daemons are created on demand up to a configurable maximum number per service.

Postfix daemons terminate voluntarily, either after being idle for a configurable amount
of time, or after having serviced a configurable number of requests. Exceptions to this
rule are the resident queue manager, address verification server, and the TLS session
cache and pseudo-random number server.

The behavior of the master(8) daemon is controlled by the master.cf configuration file, as
described in master(5).

Options:

-c config_dir
Read the main.cf and master.cf configuration files in the named directory instead
of the default configuration directory. This also overrides the configuration
files for other Postfix daemon processes.

-D After initialization, run a debugger on the master process. The debugging command
is specified with the debugger_command in the main.cf global configuration file.

-d Do not redirect stdin, stdout or stderr to /dev/null, and do not discard the
controlling terminal. This must be used for debugging only.

-e exit_time
Terminate the master process after exit_time seconds. Child processes terminate at
their convenience.

-t Test mode. Return a zero exit status when the master.pid lock file does not exist
or when that file is not locked. This is evidence that the master(8) daemon is not
running.

-v Enable verbose logging for debugging purposes. This option is passed on to child
processes. Multiple -v options make the software increasingly verbose.

-w Wait in a dummy foreground process, while the real master daemon initializes in a
background process. The dummy foreground process returns a zero exit status only
if the master daemon initialization is successful, and if it completes in a
reasonable amount of time.

This feature is available in Postfix 2.10 and later.

Signals:

SIGHUP Upon receipt of a HUP signal (e.g., after "postfix reload"), the master process re-
reads its configuration files. If a service has been removed from the master.cf
file, its running processes are terminated immediately. Otherwise, running
processes are allowed to terminate as soon as is convenient, so that changes in
configuration settings affect only new service requests.

SIGTERM
Upon receipt of a TERM signal (e.g., after "postfix abort"), the master process
passes the signal on to its child processes and terminates. This is useful for an
emergency shutdown. Normally one would terminate only the master ("postfix stop")
and allow running processes to finish what they are doing.

DIAGNOSTICS

       Problems  are  reported  to  syslogd(8).  The exit status is non-zero in case of problems,
       including problems while initializing as a master daemon process in the background.

ENVIRONMENT

       MAIL_DEBUG
              After initialization, start a  debugger  as  specified  with  the  debugger_command
              configuration parameter in the main.cf configuration file.

       MAIL_CONFIG
              Directory with Postfix configuration files.

CONFIGURATION PARAMETERS

       Unlike  most Postfix daemon processes, the master(8) server does not automatically pick up
       changes to main.cf. Changes to master.cf are  never  picked  up  automatically.   Use  the
       "postfix reload" command after a configuration change.

RESOURCE AND RATE CONTROLS

       default_process_limit (100)
              The default maximal number of Postfix child processes that provide a given service.

       max_idle (100s)
              The  maximum  amount  of  time  that  an  idle  Postfix daemon process waits for an
              incoming connection before terminating voluntarily.

       max_use (100)
              The maximal number of incoming connections  that  a  Postfix  daemon  process  will
              service before terminating voluntarily.

       service_throttle_time (60s)
              How  long  the  Postfix  master(8) waits before forking a server that appears to be
              malfunctioning.

       Available in Postfix version 2.6 and later:

       master_service_disable (empty)
              Selectively disable master(8) listener ports by service type or by service name and
              type.

MISCELLANEOUS CONTROLS

config_directory (see 'postconf -d' output)
The default location of the Postfix main.cf and master.cf configuration files.

daemon_directory (see 'postconf -d' output)
The directory with Postfix support programs and daemon programs.

debugger_command (empty)
The external command to execute when a Postfix daemon program is invoked with the
-D option.

inet_interfaces (all)
The network interface addresses that this mail system receives mail on.

inet_protocols (all)
The Internet protocols Postfix will attempt to use when making or accepting
connections.

import_environment (see 'postconf -d' output)
The list of environment parameters that a Postfix process will import from a non-
Postfix parent process.

mail_owner (postfix)
The UNIX system account that owns the Postfix queue and most Postfix daemon
processes.

process_id (read-only)
The process ID of a Postfix command or daemon process.

process_name (read-only)
The process name of a Postfix command or daemon process.

queue_directory (see 'postconf -d' output)
The location of the Postfix top-level queue directory.

syslog_facility (mail)
The syslog facility of Postfix logging.

syslog_name (see 'postconf -d' output)
The mail system name that is prepended to the process name in syslog records, so
that "smtpd" becomes, for example, "postfix/smtpd".

FILES

       To expand the directory names below into their actual values, use  the  command  "postconf
       config_directory" etc.

       $config_directory/main.cf, global configuration file.
       $config_directory/master.cf, master server configuration file.
       $queue_directory/pid/master.pid, master lock file.
       $data_directory/master.lock, master lock file.

LICENSE

       The Secure Mailer license must be distributed with this software.

AUTHOR(S)

       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA

                                                                                 MASTER(8postfix)