phpman > man > master(8postfix)

MASTER(8postfix)                                                                    MASTER(8postfix)



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  dae‐
       mons 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  control‐
              ling 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 run‐
              ning.

       -v     Enable verbose logging for debugging purposes. This option is passed on to child  pro‐
              cesses. 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 run‐
              ning 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 configu‐
              ration 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 mal‐
              functioning.

       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  connec‐
              tions.

       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  exam‐
              ple, "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 con‐‐
       fig_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.

SEE ALSO
       qmgr(8), queue manager
       verify(8), address verification
       master(5), master.cf configuration file syntax
       postconf(5), main.cf configuration file syntax
       postlogd(8), Postfix logging
       syslogd(8), system logging

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)