Glasgow Local Users Getting Started Guide

The Glasgow cluster is open to all researchers at the University using grid methods. In addition the Glasgow cluster is part of ScotGrid, the EGEE project and the WLCG grid - if you are a member of a supported virtual organisation (VO) from anywhere in the world you will be able to use our cluster.

Preparing to Use the Cluster

Prerequisite: Get a Grid Certificate

You won't be able to use the cluster at all unless you have a grid certificate. Within the UK certificates are issued by the UK eScience CA: http://www.grid-support.ac.uk/ca/.

You will have to show photo ID to the registrar - currently at Glasgow this is John Watt in NeSC (Kelvin Building).

If you have never used certificates before please read the basic documentation.

Join a VO

The easiest way to use grid resources, even just the ones at Glasgow, is to join a Virtual Organisation, or VO. This is like a group for the grid.

If your project doesn't yet have a VO then you can join the join the gridpp VO. You'll need to use the browser which has your certificate in it. When you've verified that this method works we will help you to setup a real VO for your project.

Get Local Access To The Cluster

Asking for Access

As we like to control all access to the cluster via people's grid certifiicates we need to know your identity on the grid, which is the distinguished name, or DN, of your certificate.

The CA explains how to find out your DN, so that you can tell us.

Once you have your DN then:

1. You must agree to be bound by the latest version of the JSPG Grid Acceptable Use Policy document.
2. Email your agreement and your certificate's DN to the cluster team at [1].

If you have access to a grid enabled copy of ssh (called gsissh) then this is all you need to do. If you do not then you should also email us an ssh v2 key. We will allow this vanilla normal ssh access only from on campus, whereas gsissh, which is more secure, is allowed from anywhere.

We'll email you when we have setup your local account.

Logging In

gsissh

Login to svr020.gla.scotgrid.ac.uk on port 2222:

 $ grid-proxy-init
 ...
 $ gsissh -p 2222 svr020.gla.scotgrid.ac.uk

Plain ssh

You'll need to know your local username (usually glaNNN, gla123 for instance), and have already sent us a public SSH key as described above. Then login to svr020.gla.scotgrid.ac.uk on the usual ssh port:

 $ ssh gla123@svr020.gla.scotgrid.ac.uk

Prepare Your Work Environment

Now that you've logged in to the system you can compile your applications and prepare any necessary data files.

Shared Paths

For security reasons we cannot share the home directory you have on svr020 with the cluster's batch system. So anything you put in your home directory is invisible to your running jobs!

Instead we have a shared data area, where you should put your files. At the moment this is /cluster/share/USERNAME (USERNAME is again usually something like glaNNN), however we recomend always refering to this directory through the environment variable CLUSTER_SHARED as we don't guarrantee the absolute path.

Coping Files

You can use gsiscp / scp to copy data and source codes into your shared area. One minor gotcha with gsiscp is that specifiying the port 2222 is done with an uppercase -P, not lowercase (which is for preserving permissions). See the man page for all the options).

Copying your Grid Certificate

One file you definately have to copy onto the cluster is a copy of your grid certificate, which you will need to actually run jobs. To get this onto the cluster

1. Backup your certificate to a file from your browser. (Please remember to use a strong password!)
2. Copy the backup file onto the cluster.
3. Unpack the file on svr020 into globus format - the CA describes how to do this.

Tools and Compilers

Currently the environment provided on svr020 is a standard Scientific Linux 4 environment. If there are any standard SL4 tools you need which are not installed just ask us and we'll install them. Otherwise you should prepare these tools as part of your work environment.

Submit Jobs

Basic Job Submission

Once your environment is setup you can actually run some jobs. For basic job submission you can use the edg-job-* tools described in the Glasgow Job Submission Quickstart Guide. These are also introduced on the GridPP pages and described in more detail in the gLite 3 Users Guide.

If you have problems we can help, so please ask.

Managing Large Numbers of Jobs

Once you've mastered single job submission, you can look at using ganga to manage large numbers of jobs. We have a Glasgow Ganga Quickstart Guide which should get you up and running.

Security

We know you'd rather not think about it, but it's important.

As part of joining a VO you will be required to sign that VO's Acceptable Use Policy. We will only enable VOs whose AUP's are acceptable to us. If you wish login access to the cluster, then you also must agree to the JSPG AUP as stated above (read VO as my research project where necessary).

The two points of the AUP we wish to draw particular attention to are:

1. You shall [...] protect your GRID credentials (e.g. private keys, passwords) i.e. you must use suitable passphrases on grid certificates and ssh keys.
2. You shall immediately report any known or suspected security breach, which also includes informing us as a site. If there is a security emergency please inform the email addresses listed here.

Thanks!