CPUWATCH

Section: CCB CPU Watchdog (7)
Last updated: Wed 10 Jan 16:53:42 GMT 2024
Index Return to Main Contents

DEPRECATION NOTICE

This CCB documentation has been superseded by our new website: https://lumin.imm.ox.ac.uk

OVERVIEW

The CCB login nodes are provided in order to allow file managment, light development work and submission of jobs to the cluster. Since the login nodes are a shared resource which can be in use by dozens of people at once, it's not possible for us to permit a single user to monopolise on the resources. As such, a watchdog program automatically applies a nice(1) value to all user processes. The more resources you use, the higher your processes are niced.

Given the amount of processing power available on the login nodes, the likelihood is that you'll never notice this. If, however, you're running a large program and you find that your login is becoming slow, this is probably the reason. You can confirm this for yourself by running the top(1) program and looking at the NI (nice) column for your processes. The watchdog is designed to re-prioritise your running processes as soon as you start to use less CPU resources. As such, you can always get things back to normal by stopping whichever program is causing the issue.

GETTING HELP

You can email the CCB team using the email address help@imm.ox.ac.uk. Using this address ensures your email is logged and assigned a tracking number, and will go to all the core team, which means the appropriate person or people will be able to pick it up.

COPYRIGHT

This text is copyright University of Oxford and MRC and may not be reproduced or redistributed without permission.

AUTHOR

Duncan Tooke <duncan.tooke@imm.ox.ac.uk>