Report of the Theory and Computation sub-committee of CASCA, November 2001
|Members:|| || |
| David Clarke || 2000-2003 |
| Hugh Couchman || 2000-2002 |
| Martin Duncan || 2000-2003|
| Daniel Durand || 2000-2002|
N.B. Couchman proposes that he stay until the end of 2002 as chair of
the committee despite his position as secretary of CASCA if this is
acceptable to the Board.
Activities since June:
Development of the web resources continues. A summer student hired by
Couchman did some work on this as part of her duties and she will
continue to work on this during the Fall. A survey was sent out
(prompted also by the NSERC reallocation exercise) to try to better
understand the issues faced in this arena by the community. A copy of
the survey is attached. Several responses were received.
Computing needs, problems and solutions are a rapidly moving target.
One theme which is clear is that personnel support for computing is
very spotty. This is an area which the web resources will try to
target in terms of providing information which caters specifically to
the computing needs of astronomers.
24th Nov 2001
During town hall meetings over the last year and in other discussions
the issue of computing has frequently been raised as something which
The purpose of this message is to understand what are the primary
concerns of the community in this regard. The origins of this message
are twofold: the Steering Committee for the present NSERC
Reallocations exercise and the Theory and Computation Sub-Committee of
CASCA. Please take a few minutes to respond to this simple
questionnaire with comments which may be as detailed or brief as you
In the following, positions are stated with which you may or may not
agree - feel free to respond stating and justifying your views.
Let us divide computer hardware into three broad classes: desktop
(1-2cpus/<~1GB), midrange (4-16 cpus or large memory >~8GB), high end
Q1) Is there a problem obtaining (and a need to obtain) access to
hardware in any of these categories? What are the issues that face
you: cost, suitability of hardware,...? Please answer with
reference (at a minimum) to the following points:
- One can buy a very capable high-end PC (>1GHz, 1GBRAM, 200GB
disc, high end video etc.) running Linux for C$3,000. Almost
all relevant software is available under Linux (a notable
exception is a good free Fortran compiler). Perhaps the
primary alternative now is a workstation from Sun
Microsystems. At this price-point it will be less
capable. The more capable Sun systems are substantially more
expensive. What justifies the choice of a more expensive
solution? Legacy applications, local or personal familiarity
with the OS? How important are these factors?
- CFI has funded many installations throughout Canada. A
surprising number of these have members of our community
(Astro or GSC17) as primary movers. CFI has mandated that
20% of the cycles on these machines be made generally
available. Does this satisfy the community need for systems
with up to ~100cpus? If not why not? (There may be arguments
for very large systems ~1000 cpus but this is more a
question of if we need a *multidisciplinary* national
- Several people are constructing ~16 cpu systems out of PCs
and fast ethernet for ~C$15-20k - the cost of a decent
desktop from a few years ago. Are $s required for this from
equipment funds or can(/do) small groups 2 or 3 people get
together and fund these? Is there a strong need for the more
traditional modest SMP systems (which are more expensive)?
If so, for what applications and what is the justification?
- Other hardware:
- Is the cost of large storage/archiving/backup
capabilities significant or difficult to satisfy?
(Are the very inexpensive IDE RAID systems that people
are building a useful storage solution)? Are there
difficulties in handling data from remote facilities
(observatories/large computing installations)? Is
network connectivity/bandwidth a problem, locally,
provincially, nationally, internationally?
Q2) How are your computing activities supported? Support falls into a
number of categories; please answer with reference to the
following at a minimum:
- Systems support:
- Do you manage your own desktop, is it done by
students or postdocs or by someone specifically
employed for the purpose? What are the difficulties
encountered at your site in providing these services
or having these services provided? Have you explored
ways of taking advantage of similarities in
hardware/software and networks to ameliorate the
burden of the rapidly increasing number of systems?
Is developing synergies of this kind feasible, in
your opinion, within your group, department, the
- Using parallel systems:
- Do you wish to use parallel systems (such as a
Beowulf), but feel that you do not have the
expertise? What would be required to get you
there: pointers to useful references, courses,
programmer support, ...?
Q3) Are there other computing issues (difficulties/complaints) which
do not fall within any of the above discussions/points which you
would like to raise?