Migrating Desktop
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Requirements:
Every user should have a valid CrossGrid
certificate. Account and certificate
issues should be resolved before the tutorial takes place, so the user will not
be faced with such problems just at the beginning of the tutorial. For the
description and meaning of the fields please refer to the User Guide (http://wp3.crossgrid.org/ ). The User
Guide is also available on-line after clicking on the proper desktop icon
.
I. Goal: to get familiar with
user-friendly Migrating Desktop environment, to learn a few basic operations,
to understand what advanced functionality the Migrating Desktop provides.
Steps:
- Start
web browser capable of executing Java applets goes to the address of
Migrating Desktop (the applet should be loaded automatically), see chapter
2.2. You should be equipped with private certificate
and key, give a path to them. In Server settings tab, specify port number
8443. Hostname: willow.crossgrid.man.poznan.pl (or any given by a tutor).

- Learn a few basics on creating windows, adding shortcuts to
local or remote files (user Virtual Directory), saving his profile (User
Profile database).
- Grid Commander tool is available via main menu Tools->Grid Commander.
- Make a file
transfer with chosen file and source/destination sites (using Grid
Commander). Try to connect to Private Storage, GridFTP and FTP server
(menu CONNECTIONS).
II. Goal: to run
both simple job and full Grid application using the tools and infrastructure
delivered by the CrossGrid project.
·
Tutorial-dedicated
MPI application component
·
Migrating
Desktop Job Wizard
·
Application
Scheduler with MPI scheduling facility (example of running crossgrid
application)
Steps:
- The first exercise consists of simple batch job
submission (like ‘/bin/ps’ command). Open Migrating Desktop
and invoke a Job Wizard with commandline application.
- Choose
, or invoke from the main menu: Tools->Job Wizard.
The dialog similar to this one occurs:

- Choose general->Crossgrid
Commandline. The Job Submission Wizard occurs:

- In
“Arguments” specify the unix command, eg. ps –ef
- In “Description” give a description
of your job. Leave Executable path empty. This is a kind of unix shell
environment.
- For the ps command, you don’t need to fill
in the Resources fields. However, ensure that you have got selected
‘normal’ type of job.
- Choose Files for setting up the files:

In this dialog box you must specify the logical names for standard
unix streams: output and error. If you do not define them, the computational
results become lost. Clock on the three dots. The Grid Explorer will occur
(similar to this one):

At the beginning, you have no additional
filesystem mounted to the file tree. Virtual Directory is your grid home directory.
Create a new folder and give a new filenames for stdout and stderr streams in
it. These are only logical names stored in a repository. After execution of
job, they will suppose to be filled with data. Stdout at least. These files are
type “out”, no refresh rate is needed.

- Leave Environment and
Tools as they are, press Save button. Now you have a job icon on the
desktop, it allows you to resubmit it with new parameters on demand.
Submit button launch the action. If job is successfully submitted, the
confirmation similar to that will occur:

- From main menu, choose
Tools->Job Monitor, press Refresh all, and observe the status of your
job. If you have many job submitted, please refer to the proper Job ID or
Name.

- How to obtain a
result? Press Details button. You will see a dialog:

Go to Files tab,
and choose StdOutput item, then press Visualize button. The proper visualiser
will be launched automatically. In this case, text viewer. You can also refer
to the Grid Commander, and do some well-known file operation on the output
file.
- The second MD
submission exercise takes place with real grid application choosing the
provided MPI application (eg. Air Pollution)
- Choose
, or invoke from the main menu: Tools->Job Wizard.
And then, choose Applications->Air Pollution. The dialog similar to
this one occurs:

- Fill in every needed
form, including application-specific parameters (ARGUMENTS),
Executable path (DESCRIPTION tab) set to:
/flatfiles/SE00/cg/wp1_4_4/STEMII_SE00.exe
hostname (RESOURCES -> DEFINITION) set
to: cg01.ific.uv.es:2119/jobmanager-pbs-infinite
Job type set to ‘mpich’, give
a number of spawned processes.
Choose FILES (add Name=mapadebits.bmp,
StdError and StdOutput and create them in their virtual space – use Grid
Explorer), set Refresh=number of seconds, eg.: 5 – mapadebits refresh,
eg.:

- Submit this job.
- Launch Job Monitoring
tool and find your Job ID (Name), Press Refresh All button.
- Wait until your job
becomes in RUNNING state. In Job Monitoring Tool, choose Job Details of
your job, and then Files tab. Highlight mapadebits.bmp field, and click
Visualize button.
- Set refresh period to
several seconds (eg. 1) and watch the job progress:

You should be
able to observe the example of semi-interactivity support in MD environment. No
full interaction provided in that exercise.
Comments:
- the application being submitted in this exercise
should last not too long, so the user can watch its finalization, and
definitely not too short, because there are some exercises involving
monitoring of this application; probably a time span of 45-60 minutes
would be good enough
- the application will contain a piece of MPI code
so there is an opportunity to show functionalities of various MPI
dedicated tools (MPI validation, MPI scheduling, MPI site benchmarking and
others)
- the MPI code of the application should be linked
with the library prepared in Task 2.2 so the validation log file retrieval
during tutorial is possible (see Subsection 4.2)
- the application should be compiled with the
options which allow G-PM application monitoring (see Subsection 4.1)
- the code of the application could optionally be
instrumented with probes defined by G-PM tool to obtain some specific
monitoring data to more complex analysis (see Subsection 4.1); it will be
available in future releases
Tutorial Application description:
- instead of the applications being developed in WP
1, there will be applied a simplified application, less complex and more
independent (no so much legacy software dependencies)
- there is a proposition to use an MPI-based
self-organizing maps (SOM) application – it has a good complexity
level (can be understood and explained more easily in comparison to normal
CrossGrid application) and it is still quite interesting for the user
- it has a visualization through SVG graphics file
so it can be shown both in the Migrating Desktop and Application Portal
- it needs a file with input data, so the mechanism
of setting the input file for the submitted job can also be presented
New feature worth testing:
Multiple private storage accessing.
MPI jobs submission.
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