MONARC Task 4.2  Computing Model Architecture/System Design

This task addresses the issues of hardware and network architecture of
the distributed computing systems to be modelled.  In general this task
will provide information on architectures used at major HEP computing
centers for previous and current generations of experiments, of plans
of major centers for future experiments, and of technology and cost
trends for the major components (CPU, disk, mass storage and networks)
of potential distributed computing systems.  This information will be
fed into the model simulations so that models can be grounded in reality
(both technologically and sociologically), so that models can be
optimized based on expected costs, and so that the dependence of the
models on costs and technology projections can be clearly seen.  The
information will also be used to suggest avenues of study for the
testbed task.

Sub-tasks:


1) Survey of existing computing architectures:

Descriptions of computing architectures used by current experiments
should be prepared, concentrating on LEP, FNAL Collider, and CERN and
FNAL large fixed target experiments.  Architectural descriptions should
include:
 * central CPU for computing intensive applications
 * central CPU for I/O intensive applications
 * central CPU for data analysis
 * central disk and mass storage facilities
 * distributed CPU and disk (still at central site)
 * distributed CPU, disk and mass storage at remote sites
 * desktop systems
 * local network bandwidth
 * wide area network bandwidth
 * discussion of how computing tasks are partitioned among various
   systems in a distributed architecture

Deliverables: Reports and diagrams of existing computing architecturesResources required: 3 person-months

Schedule: to be completed by 1/1/99

2) Survey of planned computing architectures:

Similar descriptions as in subtask (1) should be provided for the
plans for meeting the needs of major upcoming experiments:
 * Near term experiments: BABAR, BELLE, CDF, D0, HERA-B, RHIC
 * Later experiments: LHC

Deliverables: Reports and diagrams of planned computing architectures

Resources required: 4 person-months

Schedule: to be completed by 4/1/99

3) Survey of potential regional centers and proposed architectures:

Potential sites for LHC regional centers should be identified and surveyed
as to plans for hardware deployment and personnel support expected to be
available.  It should be recognized that there are likely to be several
different styles of regional centers, from comprehensive centers offering
large amounts of CPU, disk and mass storage for all stages of the analysis
process, to centers specializing in certain components ofthe full analysis
stream.  Different amounts of support and different topologies should also
be considered.  Models must take these differences into account.  surveys
should include:
 * Major HEP labs (existing large computing centers); and
 * Other potential sites, including "distributed" centers.

Deliverables: Reports and diagrams of architectures and potential hardware
and manpower deployment for candidate regional centers.

Resources required: 4 person-months

Schedule: to be completed by 4/1/99

4) Technology evaluation and cost tracking:

Realistic models require up-to-date estimates of hardware cost and
performance.  This subtask will require both market tracking and
measurements of hardware components as they are acquired by participating
institutes in the MONARC collaboration, in the categories of:
 * CPU;
 * Disk; and
 * mass storage.

Deliverables: Reports and spreadsheets showing price/performance
  for different computing model components and evaluation reports
  on new and unusual hardware solutions.

Resources required: .2 FTE's for the 18 month duration of the project
  (.3 person-years total) and use of existing hardware

Schedule: ongoing

5) Network performance and cost tracking

Networks are a critical component of all distributed computing models,
and availability is influenced both by technological and external forces.
The most accurate projections for network performance are a crucial input
to any distributed architecture models.  Measurements of current performance
and projections of future availability and cost should be acquired in
conjunction with other groups, in the categories of:
 * International networks;
 * National networks; and
 * End-user network access.

Deliverables: Reports and spreadsheets showing price/performance of
  local and wide area networks, plausible projections into the
  future, and analyses of potential political and sociological
  issues affecting network availability.

Resources required: .2 FTE's for the 18 month duration of the project
  (.3 person-years total)