ISS has two general purpose Timesharing Services available for authorised use. It must be emphasised that the main function of a timesharing service is to provide a fast response for interactive work. Since this does not normally take all the power of the machine, non-interactive use is allowed provided that it does not interfere with interactive users. We have found that the performance of these services has been considerably affected by some users running large and/or large numbers of background jobs.
People who wish to regularly run intensive background jobs are advised to investigate the condor grid computing service.
As it is important that computing resources are shared out fairly, and that a good interactive response is provided, especially during prime shift, background jobs which draw attention to themselves by excessive use of system resources, such as processor time or memory, may be de-prioritised or cancelled by operations staff without prior warning.