Speaker
Dr
Fons Rademakers
(CERN)
Description
The goal of PROOF (Parallel ROOt Facility) is to enable interactive
analysis of large data sets in parallel on a distributed cluster or
multi-core machine. PROOF represents a high-performance alternative
to a traditional batch-oriented computing system.
The ALICE collaboration is planning to use PROOF at the CERN Analysis Facility
(CAF) and has been stress testing the system since mid 2006 on a 40 machine
pilot cluster. The ALICE CAF is expected to grow to around 500 machines.
The testing by ALICE has allowed us to identify missing functionality and
to improve the system in many ways. Areas of significant development
include: a dataset manager to optimally distribute data on the cluster;
facilities to upload and manage the experiment software; a new "packetizer"
which significantly reduces the end-of-query tails; a worker-level
priority-based scheduling system to control the fraction of resources
assigned to a group of users; improved error handling and user feedback
mechanism; and much more.
The CMS collaboration is also actively investigating PROOF as Tier-2
analysis facility.
Current activities focus on the development of a central scheduling
system that uses the OLBD/XROOTD control network as information routing
system. This scheduler aims to improve resource sharing in a multi-user
environment, taking per-query decisions based on the status
of the farm, the query requirements and the history and priorities of
the user.
In this paper we will describe in detail the recent developments, the
status of the current activities, and outline the future plans to bring
PROOF in production for LHC analysis.
Primary author
Dr
Fons Rademakers
(CERN)
Co-authors
Mr
Bertrand Bellenot
(CERN)
Dr
Gerardo Ganis
(CERN)
Mr
Jan Iwaszkiewicz
(CERN)
Dr
Maarten Ballintijn
(MIT)
Dr
Rene Brun
(CERN)
