Ubuntu Manpage: master - Postfix master process

Provided by: postfix_3.8.1-2ubuntu0.2_amd64

NAME

       master - Postfix master process

SYNOPSIS

       master [-Dditvw] [-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.

-i Enable init mode: do not become a session or process group leader; and similar to
-s, do not redirect stdout to /dev/null, so that "maillog_file = /dev/stdout"
works. This mode is allowed only if the process ID equals 1.

This feature is available in Postfix 3.3 and later.

-s Do not redirect stdout to /dev/null, so that "maillog_file = /dev/stdout" works.

This feature is available in Postfix 3.4 and later.

-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) or postlogd(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 (see 'postconf -d output')
              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 privileged Postfix  process  will  import
              from a non-Postfix parent process, or name=value environment overrides.

       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)
              A prefix that is prepended to the process name in  syslog  records,  so  that,  for
              example, "smtpd" becomes "prefix/smtpd".

       Available in Postfix 3.3 and later:

       service_name (read-only)
              The master.cf service name of a Postfix daemon process.

       Available in Postfix 3.6 and later:

       known_tcp_ports (lmtp=24, smtp=25, smtps=submissions=465, submission=587)
              Optional setting that avoids lookups in the services(5) database.

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

       Wietse Venema
       Google, Inc.
       111 8th Avenue
       New York, NY 10011, USA

                                                                                 MASTER(8postfix)