Speaker
With a forward look to future evolution, discuss the issues you have encountered (or that you expect) in using the EGEE infrastructure. Wherever possible, point out the experience limitations (both in terms of existing services or missing functionality)
Easygrid has performed its tasks submitting, recovering results,
and providing
listings for further analysis when something goes wrong. However,
data
services (store, recover and transfer data) still a bottleneck.
Most worker nodes
were running distributed analysis (an IO bond application) with
50% IOWAIT,
and consequently 50% CPULOAD. This is a severe efficiency problem
that needs
to be tackled before CERN distributed analysis production starts
next year.
Describe the scientific/technical community and the scientific/technical activity using (planning to use) the EGEE infrastructure. A high-level description is needed (neither a detailed specialist report nor a list of references).
We automate job submission system to grid farms with EasyGrid, an
intermediate layer between grid middleware and user software that
provides
functionality to perform data and functional parallelism. Users
without grid skills
were able to use grid. The case studies were hadronic tau decays
distributed
analysis and neutral pion discrimination using genetic
programming algorithms.
Report on the experience (or the proposed activity). It would be very important to mention key services which are essential for the success of your activity on the EGEE infrastructure.
Data gridification: The first benchmark was eta(540)
reconstruction to test what
is the best approach to data distribution. The second benchmark
was tau
decays to neutral pions. This benchmark selected events over 482
million real
events and generated 5 million MC events. The third benchmark was
search for
anti-deuterons in all events available in BaBar Run 3 (1,500
million events in
one week using 250 computers in parallel).
Functional gridification: Genetic programming was used to
discriminate
reconstruction of real neutral pions from background evolving a
mathematical
model with maps the variables hyperspace to a real value, an
algebraic function
of pions kinematics variables. Applying the discriminator to a
given pair of
gammas, if the discriminate value is bigger than zero, the pair
of gammas is
deemed to come from pion decay. Otherwise, the pair is deemed to
come from
another (background) source.
More information see http://www.hep.man.ac.uk/u/jamwer/
Describe the added value of the Grid for the scientific/technical activity you (plan to) do on the Grid. This should include the scale of the activity and of the potential user community and the relevance for other scientific or business applications
The added value was a user’s transparent framework for reliable data
gridification (support execution and results’ recovery of many
copies of the
same binary code running independently and at same time in many
computers
with different data files) and functional gridification (one
binary code running
distributed in many grid computers at same time).
Data gridification can be used to run Monte Carlo Events
generation, raw data
analysis, any Root application, or any other generic software.
Functional parallelism is done through a library with several
functions to run
conventional software on the grid with minor changes in the
source code. It
provides an efficient and secure communication mechanism to allow
data
transfer between jobs in different worker nodes. If any node goes
down, the
master program re-submits the task to another server. For more
information
see http://www.geocities.com/jamwer2002/gridgeral.pdf
