[[PageOutline(1-10,DRM4G Tutorial)]]

= About DRM4G =

'''DRM4G''' is an open platform, based on [[http://www.gridway.org/doku.php?id=start|GridWay]] , to define, submit, and manage computational jobs. DRM4G is a [[https://www.python.org|Python]] ('''2.6+''', '''3.3+''') implementation that provides a single point of control for computing resources without installing any intermediate middlewares. As a result, a user is able to run the same job on laptops, desktops, workstations, clusters, supercomputers, and any grid. 

= Start Guide =

In order to install DRM4G, an installation script is provided. Type the command below on your shell terminal:

{{{
#!sh
$ wget --no-check-certificate -O- https://meteo.unican.es/work/DRM4G/install.sh | bash

==========================
DRM4G installation script
==========================

--> Checking the last version of DRM4G ...

--> DRM4G version selected: 2.4.1

--> Downloading drm4g-2.4.1.tar.gz ...

--> Unpacking drm4g-2.4.1.tar.gz in directory /home/USER ...

--> Installing DRM4G python requirements locally ...

====================================
Installation of DRM4G 2.4.1 is done!
====================================

In order to work with DRM4G you have to enable its 
environment with the command:

    . /home/USER/drm4g/bin/drm4g_init.sh

You need to run the above command on every new shell you 
open before using DRM4G, but just once per session.
}}}

By default, it will install DRM4G on your current directory. But, you can download the installation script:

{{{
#!sh
$ wget --no-check-certificate https://meteo.unican.es/work/DRM4G/install.sh
}}}

And run it manually:
{{{
#!sh
$ bash ./install.sh [options]
}}}
The options available are:

 * -d, --dir DIRECTORY: Install DRM4G into a directory.
 * -V, --version: Version to install.
 * -h, --help: Print help text.

= My first job =

[[NoteBox(note, If the the directory `~/.drm4g` does not exist\, `drm4g` will create one with a local configuration)]]

1. Enable DRM4G:
{{{
#!sh
[user@mycomputer~]$. /home/user/drm4g/bin/drm4g_init.sh
}}}

1. Start up DRM4G :
{{{
#!sh
[user@mycomputer~]$ drm4g start
Creating a DRM4G local configuration in '/home/user/.drm4g'
Creating '/home/user/.drm4g/var/acct' directory
Coping from '/home/user/drm4g/etc' to '/home/user/.drm4g/etc'
Starting DRM4G .... 
 OK
Starting ssh-agent ...
 OK
}}}
1. Show information about all available resources and their host :
{{{
#!sh
[user@mycomputer~]$ drm4g resource list
RESOURCE            STATE               
localmachine        enabled

[user@mycomputer~]$ drm4g host list
HID ARCH       JOBS(R/T) LRMS       HOST                
0   x86_64           0/0 fork       localmachine

[user@mycomputer~]$ drm4g host list 0
HID ARCH       JOBS(R/T) LRMS       HOST                
0   x86_64           0/0 fork       localmachine        

QUEUENAME      JOBS(R/T) WALLT CPUT  MAXR  MAXQ 
default              0/0 0     0     1     1               
}}}
1. Create a job template :
{{{
#!sh
[user@mycomputer~]$ echo "EXECUTABLE=/bin/date" > date.job
}}}
1. Submit the job :
{{{
#!sh
[user@mycomputer~]$ drm4g job submit date.job
ID: 0
}}}
1. Check the evolution of the job :
{{{
#!sh
[user@mycomputer~]$ drm4g job list 0
JID DM   EM   START    END      EXEC    XFER    EXIT NAME            HOST                                          
0   pend ---- 19:39:09 --:--:-- 0:00:00 0:00:00 --   date.job        --                        
}}}
 If you execute successive `drm4g job list 0`, you will see the different states of this job:
{{{
0   pend ---- 19:39:09 --:--:-- 0:00:00 0:00:00 --   date.job        --                                            
0   prol ---- 19:39:09 --:--:-- 0:00:00 0:00:00 --   date.job        --                                                            
0   wrap pend 19:39:09 --:--:-- 0:00:00 0:00:00 --   date.job localhost/fork                                                                         
0   wrap actv 19:39:09 --:--:-- 0:00:05 0:00:00 --   date.job localhost/fork                                                         
0   epil ---- 19:39:09 --:--:-- 0:00:10 0:00:00 --   date.job localhost/fork
0   done ---- 19:39:09 19:39:27 0:00:10 0:00:01 0    date.job localhost/fork         
}}}
 * `pend`: The job is waiting for a resource to run on. 
 * `prol` :The remote system is being prepared for execution. 
 * `wrap pend` :The job has been successfully submitted to the computing resource and it is waiting.
 * `wrap actv`:The job is being executed by the computing resource. 
 * `epil`:The job is finalizing.
 * `done`:The job has finished.
1. Results are standard output (stdout) and standard error (stderr), both files will be in the same directory of job template:
{{{
#!sh
[user@mycomputer~]$ cat stdout.0
Mon Jul 28 12:29:43 CEST 2014

[user@mycomputer~]$ cat stderr.0

}}}

= How to configure a TORQUE/PBS resource =

In order to configure a TORQUE/PBS cluster accessed through ssh protocol, you can follow the next steps:

1. Generate a public/private key pair without password :
{{{
#!sh
[user@mycomputer~]$ ssh-keygen -t rsa -b 2048 -f $HOME/.ssh/meteo_rsa -N ""
}}}
1. Configure the `meteo` resource :
{{{
#!sh
[user@mycomputer~]$ drm4g resource edit
[meteo]
enable            = true
communicator      = ssh
username          = user
frontend          = ui.macc.unican.es
private_key       = ~/.ssh/meteo_rsa
lrms              = pbs
queue             = qrid
max_jobs_running  = 1
max_jobs_in_queue = 2
}}}
1. List and check if resource has been created successfully :
{{{
#!sh
[user@mycomputer~]$ drm4g resource list
RESOURCE            STATE               
meteo               enabled
}}}

That's it! Now, you can summit jobs to `meteo`.

= User Scenarios =

== Single Jobs ==

== Array Jobs ==

== MPI Jobs ==