Department of Engineering

Non-Teaching Use of the System

The network of workstations in the DPO, The Teaching System, is primarily intended to provide a modern teaching facility for over 1000 undergraduates. When not being used for teaching, the system provides a valuable computing resource for research. The Department wants the system to be as widely available as possible for research and private study as well as teaching but is concerned that adequate performance must be available for teaching during classes and therefore some restrictions on other use are necessary.

The need for and timing of the restricted periods is kept under regular review and users will be kept informed of any changes. Please note that un-timetabled teaching-related use of the system takes priority over un-timetabled research use, reflecting the primary role of the system as a teaching resource, but it is very rare for the load to be high enough outside restricted periods for this to a factor. We very much hope that users will voluntarily adhere to these restrictions so that the need for rigidly enforced automatic access controls can be avoided.

General Guidelines on Use

gate.eng.cam.ac.uk is not used for timetabled teaching but comprises low powered machines intended for external access and "light work" only. Processes making excessive use of this system may be killed without warning.

If you need to do more compute intensive work please use one of the cluster servers (tw100, tw200, tw300, tw400, tw500, tw600 or tw900) outside teaching periods. tw800 is the same kind of machine but is not used for timetabled teaching - it is intended for use by Part IIB students (who have priority at all times) and some research activities. All these systems run Linux.

Whilst the printers on the teaching system may be used for non-teaching work, anyone wishing to send significant amounts to these printers should avoid timetabled teaching periods and if in doubt check with the operators first of all. Such use must be charged to the user's personal print quota.

There is further advice on the use of the Teaching System for research purposes in the Overview of Research Computing Facilities.

1. No remote logins are allowed to timetabled clusters during teaching periods.

2. During busy periods all non-timetabled users should ask the demonstrator whether they can use a machine (rather than waiting for a demonstratator to have to tell them to log off!).

3. The operators will monitor the system at times during a laboratory or when requested by demonstrators.

4. Anyone who ignores these rules will receive two warnings, any further transgressions will result in disciplinary action being taken.

5. The message of the day will be changed on the clusters during busy periods to remind people that access is restricted.

General Guidelines on Use During Peak Teaching Times

Workstation clusters reserved for teaching classes are clearly identified by notices at the end of each bench. All other users should vacate these machines in good time before the start of a class to allow incoming students to find a free workstation with minimum delay. This is particularly important during the Part I courses when up to ninety undergraduates are attempting to login at the same time. Workstations in unreserved clusters are often available for non-teaching use but please check with a demonstrator.

Postgraduates and staff who use the system for research may be asked to restrict their use during peak teaching hours to activities which generate only a light load on the system as a whole. Such activities include:

• reading mail and news
• Web browsing
• editing files
• small scale compilation
• execution of small very short running "number-crunching" programs which make minimal demands on memory or disk.

If the system becomes overloaded it will be necessary to reduce the load by terminating non-teaching activities, possibly without warning.

At all times, long running jobs should be run using the Grid Engine system.