SGE_SHEPHERD(8) 				      Sun Grid Engine Administrative Commands					   SGE_SHEPHERD(8)

NAME

       sge_shepherd - Sun Grid Engine single job controlling agent

SYNOPSIS

       sge_shepherd

DESCRIPTION

       sge_shepherd  provides  the  parent  process functionality for a single Sun Grid Engine job.  The parent functionality is necessary on UNIX
       systems to retrieve resource usage information (see getrusage(2)) after a job has finished. In addition, the sge_shepherd forwards  signals
       to  the	job,  such  as the signals for suspension, enabling, termination and the Sun Grid Engine checkpointing signal (see sge_ckpt(1) for
       details).

       The sge_shepherd receives information about the job to be started from the sge_execd(8).  During the  execution	of  the  job  it  actually
       starts  up  to 5 child processes. First a prolog script is run if this feature is enabled by the prolog parameter in the cluster configura-
       tion. (See sge_conf(5).)  Next a parallel environment startup procedure is run if the job is a parallel job. (See sge_pe(5) for more infor-
       mation.)  After that, the job itself is run, followed by a parallel environment shutdown procedure for parallel jobs, and finally an epilog
       script if requested by the epilog parameter in the cluster configuration. The prolog and epilog scripts as well as the parallel environment
       startup	and  shutdown  procedures are to be provided by the Sun Grid Engine administrator and are intended for site-specific actions to be
       taken before and after execution of the actual user job.

       After the job has finished and the epilog script is processed, sge_shepherd retrieves resource usage statistics about the job, places  them
       in a job specific subdirectory of the sge_execd(8) spool directory for reporting through sge_execd(8) and finishes.

       sge_shepherd  also places an exit status file in the spool directory. This exit status can be viewed with qacct -j JobId (see qacct(1)); it
       is not the exit status of sge_shepherd itself but of one of the methods executed by sge_shepherd.  This exit status can have several  mean-
       ings,  depending on in which method an error occurred (if any).	The possible methods are: prolog, parallel start, job, parallel stop, epi-
       log, suspend, restart, terminate, clean, migrate, and checkpoint.

       The following exit values are returned:

       0      All methods: Operation was executed successfully.

       99     Job script, prolog and epilog: When FORBID_RESCHEDULE is not set in the configuration (see sge_conf(5)),	the  job  gets	re-queued.
	      Otherwise see "Other".

       100    Job script, prolog and epilog: When FORBID_APPERROR is not set in the configuration (see sge_conf(5)), the job gets re-queued.  Oth-
	      erwise see "Other".

       Other  Job script: This is the exit status of the job itself. No action is taken upon this exit status because the  meaning  of	this  exit
	      status is not known.
	      Prolog, epilog and parallel start: The queue is set to error state and the job is re-queued.
	      Parallel stop: The queue is set to error state, but the job is not re-queued. It is assumed that the job itself ran successfully and
	      only the clean up script failed.
	      Suspend, restart, terminate, clean, and migrate: Always successful.
	      Checkpoint: Success, except for kernel checkpointing: checkpoint was not successful, did not happen (but migration  will	happen	by
	      Sun Grid Engine).

RESTRICTIONS

       sge_shepherd should not be invoked manually, but only by sge_execd(8).

FILES

       sgepasswd   contains   a  list  of  user  names	 and   their corresponding encrypted passwords. If available, the password  file  will	be
       used   by  sge_shepherd. To change the contents of this file please use the sgepasswd command. It is not advised to  change that file manu-
       ally.
       <execd_spool>/job_dir/<job_id>	  job specific directory

SEE ALSO

       sge_intro(1), sge_conf(5), sge_execd(8).

COPYRIGHT

       See sge_intro(1) for a full statement of rights and permissions.

SGE 6.2u5							      $Date$							   SGE_SHEPHERD(8)