NAME

       pbs_sched_cc - pbs C scheduler

SYNOPSIS

       pbs_sched [-a alarm] [-d home] [-L logfile] [-p file] [-S port] [-R port] [-c file]

DESCRIPTION

       The  pbs_sched  program  runs  in  conjunction with the PBS server.  It queries the server
       about the state of PBS and communicates with  pbs_resmon  to  get  information  about  the
       status  of running jobs, memory available etc.  It then makes decisions as to what jobs to
       run.

       pbs_sched must be executed with root permission.

OPTIONS

       -a alarm       This specifies the time in seconds to wait for a schedule  run  to  finish.
                      If  a  script  takes  too  long to finish, an alarm signal is sent, and the
                      scheduler is restarted.  If a core file  does  not  exist  in  the  current
                      directory, abort() is called and a core file is generated.  The default for
                      alarm is 180 seconds.

       -d home        This specifies the PBS  home  directory,  PBS_HOME.   The  current  working
                      directory  of  the scheduler is PBS_HOME/sched_priv.  If this option is not
                      given, PBS_HOME defaults to $PBS_SERVER_HOME  as  defined  during  the  PBS
                      build procedure.

       -L logfile     Specifies an absolute path name of the file to use as the log file.  If not
                      specified, the scheduler will open a file named for the current date in the
                      PBS_HOME/sched_logs directory (see the -d option).

       -p file        This  specifies  the  "print"  file.   Any  output from the C code which is
                      written to standard out or standard error will be written to this file.  If
                      this     option    is    not    given,    the    file    used    will    be
                      PBS_HOME/sched_priv/sched_out .  See the -d option.

       -S port        This specifies the port to use.  If this option is not given,  the  default
                      port for the PBS scheduler is used.

       -R port        This  specifies  the  resource  monitor port to use.  If this option is not
                      given, the default port for the PBS mom is used.  NOTE:  this  option  only
                      makes  the  mom  port  available to the scheduler writer.  It doesn't force
                      them to use it.

       -c file        Specify a configuration file, see description below.  If this is a relative
                      file  name  it  will be relative to PBS_HOME/sched_priv, see the -d option.
                      If the -c option is not supplied, pbs_sched will  not  attempt  to  open  a
                      configuration file.

       The  options  that  specify file names may be absolute or relative.  If they are relative,
       their root directory will be PBS_HOME/sched_priv.

USAGE

       This version of the scheduler requires knowledge of  the  C  language  and  the  PBS  API.
       Source  code  is  provided for a main program for the scheduler.  The site must supply the
       heart of the program.  When invoked, the main program performs general initialization  and
       housekeeping  chores.   Then a locally supplied function, schedinit() is called to perform
       site specific initialization.

       In the main loop, a locally supplied function, schedule() is called to make the scheduling
       decisions and perform any required actions.  Information about jobs and queues is obtained
       from the Server through the standard PBS API as found in libifl.a.  Information about  the
       execution host(s) is obtained from the Resource Monitor.  Routines to communicate with the
       Resource Monitor are found in libnet.a.

       If the processing takes more than the allotted time, the scheduler  will  restart  itself.
       The default amount of time is three minutes.  This can be changed with the -a option.

       On receipt of a SIGHUP signal, the scheduler will close and reopen its log file and reread
       its configuration file (if any).

CONFIGURATION FILE

       A configuration file may be specified with the -c  option.   This  file  may  be  used  to
       specify  the  hosts  (servers)  which  are allowed to connect to pbs_sched.  The hosts are
       specified in the configuration file in a manor identical to that used in pbs_mom.

       clienthost
              One or more servers, one per line, may be specified:

              $clienthost   hostname +.IP  restricted  Allows  connections  from  non-priviledged
              ports on the named hosts.  Typically only used with Mac OSX:

              $restricted   hostname

              Two  host  names are always allowed to connection to pbs_sched, "localhost" and the
              name returned to pbs_sched by the system call gethostname().  These names need  not
              be specified in the configuration file.

       The  configuration file must be "secure".  It must be owned by a user id and group id less
       than 10 and not be world writable.

FILES

       $PBS_SERVER_HOME/sched_priv
                 the     default     directory     for     configuration     files,     typically
                 (/usr/spool/pbs)/sched_priv.

Signal Handling

       A C based scheduler will handle the following signals:

       SIGHUP The  server  will  close  and reopen its log file and reread the config file if one
              exists.

       SIGALRM
              If the site supplied scheduling module exceeds the time limit, the Alarm will cause
              the scheduler to attempt to core dump and restart itself.

       SIGINT and SIGTERM
              Will result in an orderly shutdown of the scheduler.

       All other signals have the default action installed.

EXIT STATUS

       Upon normal termination, an exit status of zero is returned.

SEE ALSO

       pbs_sched_tcl(8B), pbs_server(8B), and pbs_mom(8B).
       PBS Internal Design Specification