Integration with afs, Integrating external queuing systems, 24 5.15. integrating external queuing systems – PAR Technologies PARASTATION5 V5 User Manual

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Integration with AFS

24

ParaStation5 Administrator's Guide

5.14. Integration with AFS

To run parallel tasks spawned by ParaStation on clusters using

AFS

, ParaStation provides the scripts

env2tok

and

tok2env

.

On the frontend side, calling

. tok2env

will create an environment variable

AFS_TOKEN

containing an encoded access token for AFS. This variable

must be added to the list of exported variables

PSI_EXPORTS="AFS_TOKEN,$PSI_EXPORTS"

In addition, the variable

PSI_RARG_PRE_0=/some/path/env2tok

must be set. This will call the script

env2tok

before running the actual program on each node.

Env2tok

itself will decode the token and will setup the AFS environment.

The commands

SetToken

and

GetToken

, which are part of the AFS package, must

be available on each node. Also, the commands

uuencode

and

uudecode

must be

installed.

Script

tok2env

:

#!/bin/bash

tmp=$IFS

IFS=" "

export AFS_TOKEN=`GetToken | uuencode /dev/stdout`

IFS=$tmp

Script

env2tok

:

#!/bin/bash

IFS=" "

echo $AFS_TOKEN | uudecode | SetToken

exec $*

5.15. Integrating external queuing systems

ParaStation can be easily integrated with batch queuing and scheduling systems. In this case, the queuing
system will decide, where (and when) to run a parallel task. ParaStation will then start, monitor and terminate
the task. In case of higher prioritized jobs, the batch system may also suspend a task using the ParaStation
signal forwarding.

Integration is done by setting up ParaStation environment variables, like

PSI_HOSTFILE

. ParaStation itself

need not be modified in any way. It is not necessary to use a remote shell (

rsh

) to start

mpirun

on the first

node of the selected partition. The batch system should only run the command on the same node where
the batch system is running, ParaStation will start all necessary processes on the remote nodes. For details
about spawning processes refer to ParaStation5 User's Guide.

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