pbs_sched(8B)								PBS							     pbs_sched(8B)

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	configura-
		      tion 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  con-
       nect 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

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