NAME

       master - Cyrus IMAP documentation

       The Cyrus IMAP master process.

SYNOPSIS

          master [ -C config-file ] [ -M alternate cyrus.conf ]
              [ -l listen queue ] [ -p pidfile ] [ -r ready_file ]
              [ -j janitor period ] [ -d | -D ] [ -L logfile ]

DESCRIPTION

       master  is the process that controls all of the Cyrus processes. This process is responsible for creating
       all  imapd,  pop3d,  lmtpd  and  timsieved  child  processes.  This  process  also   performs   scheduled
       cleanup/maintenance.

       If this process dies, then no new sessions will be started.

       It kills itself and all child processes when it receives a SIGTERM.

       master reads its configuration options out of the imapd.conf(5) file unless specified otherwise by -C.

OPTIONS

       -C alternate imapd.conf
              Use the specified configuration file config-file rather than the default imapd.conf(5).

       -M alternate cyrus.conf
              Specifies an alternate cyrus.conf for use by master.

       -l listen queue backlog
              Increase  the listen queue backlog. By default, the listen queue is set to 32.   On systems with a
              high connection rate, it may be desirable to increase this value. refer to listen(2) for details.

       -j janitor full-sweeps per second
              Sets the number of times per second the janitor should sweep the entire child table.  Leave it  at
              the  default  of  1  unless you have a really high fork rate (and you have not increased the child
              hash table size when you compiled Cyrus from its default of 10000 entries).

       -p pidfile
              Use pidfile as the pidfile.  If not specified, defaults  to  master_pid_file  from  imapd.conf(5),
              which defaults to {configdirectory}/master.pid

       -r ready_file
              Use  ready_file  as  the ready file.  If not specified, uses master_ready_file from imapd.conf(5),
              which defaults to {configdirectory}/master.ready

       -d     Start in daemon mode (run in background and disconnect from controlling terminal).

       -D     Don't close stdin/stdout/stderr. Primarily useful for debugging.  Note that -d and  -D  cannot  be
              used together; consider using -L instead.

       -L logfile
              Redirect stdout and stderr to the given logfile.

CONFIGURATION

       Upon  execution,  master  reads  its  configuration  information  out  of  the  cyrus.conf(5) file, or an
       alternative if -M is used.

       master rereads its configuration file when it receives a hangup signal, SIGHUP.  Services and events  may
       be  added,  deleted  or modified when the configuration file is reread.  Any active services removed from
       the configuration file will be allowed to run until completion.  Services added or modified to listen  on
       a privileged port may not be able to bind the port, depending on your system configuration.  In this case
       a full restart is needed.

       master  propagates  the  hangup signal, SIGHUP, to its child service processes, so that they stop waiting
       for incoming connections and exit, allowing them to be recycled.  This is useful to  make  services  take
       into  account  a  new version of the imapd.conf(5) file.  Children that are servicing a client connection
       when SIGHUP is received are allowed to run until the client logouts before being recycled. It may take  a
       long  time  until  the  client  logouts,  so  a log message is generated for processes that have not been
       recycled within 30s.

NOTES

       The environment variable CYRUS_VERBOSE can be set to log additional debugging  information.  Setting  the
       value  to  1  results  in  base  level  logging.   Setting  it  higher results in more log messages being
       generated.

       The cyr_info(8) utility's proc subcommand can be used  to  list  the  active  processes  that  master  is
       managing.

FILES

       /etc/cyrus.conf, /etc/imapd.conf, /var/run/master.pid

SEE ALSO

       cyrus.conf(5), imapd.conf(5), imapd(8), pop3d(8), lmtpd(8), timsieved(8), idled(8), cyr_info(8)

AUTHOR

       The Cyrus Team, Nic Bernstein (Onlight)

COPYRIGHT

       1993–2025, The Cyrus Team

3.10.2                                            Jun 27, 2025                                         MASTER(8)