Connecting your computer to the Xgrid at CoMPLEX

The Xgrid at CoMPLEX is a distributed computing system. Members of CoMPLEX use the Xgrid to solve computationally demanding biological problems. Adding your computer to our Xgrid means that we can use any idle moments on your computer to run our simulations.

Xgrid works very similarly to the SETI@Home project that you might be familiar with.

Connecting to the Xgrid won't effect how you use your computer. The Xgrid is only active when your computer is idle (when the screensaver is on). Also, Xgrid runs programs as the user "nobody". This user account has very limited priviledges so that the Xgrid has no access to any personal files on your computer.

Your computer doesn't have to be in UCL for you to connect it to the Xgrid. Any computer with a permanent Internet connection (ie a computer with broadband at home) can be connected to the Xgrid.

Requirements

To connect to Xgrid at CoMPLEX the you must have an Apple computer running OSX 10.4 (Tiger) or above.

Instructions to verify which version of OSX you have are availiable here.

Connecting

The following instructions are also availiable as a pdf [2.3MB].

Turn on the Xgrid Agent:

1. Click "Apple" -> "System Preferences" and choose "Sharing".

2. If the lock in the bottom left of the screen is closed, click it, and enter an administrators username and password so that you're authorised to make changes to the Sharing Preferences.

3. Select "Xgrid" from the list of services, and click "Configure".

4. In the Controller section, select "Use a specific Controller" and enter xgrid.complex.ucl.ac.uk in the address box.

5. In the "Agent accept tasks" section, choose "Only when this computer is idle". This means xgrid jobs will only run on your computer when you're not using it.

6. In the "Authentication method" section, choose the method as "None". Its fine not to have a password here- you've told your computer to only connect to Xgrid controller at CoMPLEX, so it won't be connecting to another Xgrid that you might not trust.

Next, you need to stop your computer from sleeping when it is idle. If the computer is asleep, the Xgrid agent won't run. To turn off sleeping:

1. Click "Apple" -> "System Preferences" and choose "Energy Saver".

2. Select the "Sleep" tab, and move to the scroller for "Put the computer to sleep when it is inactive for:" to "Never".

And that's it, you're done! Thank you for donating your computer to our Xgrid.

Please note that by donating your computer to the Xgrid @ CoMPLEX you do not recieve the right to perform calculations on the Xgrid.

The Xgrid @ CoMPLEX is administered by Trevor Graham. Contact him at:

This page last modified 4 December, 2006 by [ ]