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Getting an account on the UJ Research Cluster

All researchers, staff members and students at the University of Johannesburg are welcome to apply for user accounts to use the UJ Research Cluster.

Since [as of April 2009] rules for access to the Cluster are not finalised, applications will be considered individually.

Application forms for Staff and Students are being prepared; for the moment please see Contacts for information and requests. Please indicate in your request:

  • Acceptance of Usage Policy (see Policies)
  • Interest in batch system only or also Grid access
  • Field of research
  • Intended use (simulations, data analysis, computing research... )
  • Requirements for CPU
  • Requirements for temporary data storage
  • Any other specific requirements
  • For students, please let your supervisor or lecturer support your request

Using the batch system (Torque-PBS)

For using the batch processing capacity of the cluster you will need to obtain an account on the User Interface servers. By logging into the UI (using ssh) you will be able to compile your code (using the GNU Compiler Collection, versions 3.4 or 4.1.2) and run it on the Worker Nodes of the cluster.
See the Torque page for more details on how to run your code on the cluster.

It is usually very easy to adapt to the batch system those programs which require no user interaction and are written for Unix/Linux systems (this includes those Mac OsX, if they use only the BSD/Unix APIs). Programs that can process independently separate subsets of data can very easily benefit from the parallel processing offered by the batch system.
See Developing for some notes on code development, compiling, libraries.

Using the Grid

Using the Grid, either OSG or SAGrid, you can get access to the computing power not only of this cluster, but also of other centres, in South Africa and abroad. This potentially means access to huge computing capacity.

The downsides are the initial requirements for User Certificates and association to a Virtual Organisation, a slight increase in complexity in the submission of jobs, and a less homogeneous execution environment. Also, only a limited subset of the computing resources on the Grid offer MPI.

User Certificates

To use the Grid, you will need to obtain a User Certificate from a Registration Authorithy, and to be registered with a Virtual Organisation. These steps change depending on the flavour of Grid you use (OSG or SAGrid) and on the VO.
See the Certificates page for further details on User Certificates for the Grid.

For testing and training purposes, User Certificates not recognised by any VO may be specifically authorised for the UJ Cluster only. Please contact the System Administrators for details.

Virtual Organisations

A Virtual Organisation is a free association of researchers in a specific field, which joins its computing resources through the Grid. Various computing resources (clusters) on the Grid allow jobs from different subsets of the existing VOs, allocating to each different priorities. The very large experiments in Particle Physics usually define each its own VO (ATLAS, CMS, ALICE...), but in other fields, where the use of the Grid is not widespread, VOs prefer to be more comprehensive and embracing.

The UJ Cluster will initially support and allow jobs from the following VOs:

There are many other VOs not currently supported at UJ:

If you are looking for a VO in which your research may fit (and you haven't found it in the lists above), or if you want to propose a new VO to SAGrid, please address your query to the Contacts. Also, please inform us if you have found a VO to which you may want to participate; it would be preferable to discuss the matter before you propose to the VO to join, as the VO may ask for some computing capacity in return but at the moment [Feb 2009] there is not an established policy about adding other VOs to the UJ cluster.

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Page last modified on April 20, 2009, at 12:47 PM