570 research outputs found
HEP C++ Meets reality
In 2007 the CMS experiment first reported some initial findings on the impedance mismatch between HEP use of C++ and the current generation of compilers and CPUs. Since then we have continued our analysis of the CMS experiment code base, including the external packages we use. We have found that large amounts of C++ code has been written largely ignoring any physical reality of the resulting machine code and run time execution costs, including and especially software developed by experts. We report on a wide range issues affecting typical high energy physics code, in the form of coding pattern - impact - lesson - improvement
Optimizing CMS build infrastructure via Apache Mesos
The Offline Software of the CMS Experiment at the Large Hadron Collider (LHC)
at CERN consists of 6M lines of in-house code, developed over a decade by
nearly 1000 physicists, as well as a comparable amount of general use
open-source code. A critical ingredient to the success of the construction and
early operation of the WLCG was the convergence, around the year 2000, on the
use of a homogeneous environment of commodity x86-64 processors and Linux.
Apache Mesos is a cluster manager that provides efficient resource isolation
and sharing across distributed applications, or frameworks. It can run Hadoop,
Jenkins, Spark, Aurora, and other applications on a dynamically shared pool of
nodes. We present how we migrated our continuos integration system to schedule
jobs on a relatively small Apache Mesos enabled cluster and how this resulted
in better resource usage, higher peak performance and lower latency thanks to
the dynamic scheduling capabilities of Mesos.Comment: Submitted to proceedings of the 21st International Conference on
Computing in High Energy and Nuclear Physics (CHEP2015), Okinawa, Japa
IGUANA Architecture, Framework and Toolkit for Interactive Graphics
IGUANA is a generic interactive visualisation framework based on a C++
component model. It provides powerful user interface and visualisation
primitives in a way that is not tied to any particular physics experiment or
detector design. The article describes interactive visualisation tools built
using IGUANA for the CMS and D0 experiments, as well as generic GEANT4 and
GEANT3 applications. It covers features of the graphical user interfaces, 3D
and 2D graphics, high-quality vector graphics output for print media, various
textual, tabular and hierarchical data views, and integration with the
application through control panels, a command line and different
multi-threading models.Comment: Presented at the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, Ca, USA, March 2003, 6 pages LaTeX, 4 eps figures. PSN
MOLT008 More and higher res figs at
http://iguana.web.cern.ch/iguana/snapshot/main/gallery.htm
Explorations of the viability of ARM and Xeon Phi for physics processing
We report on our investigations into the viability of the ARM processor and
the Intel Xeon Phi co-processor for scientific computing. We describe our
experience porting software to these processors and running benchmarks using
real physics applications to explore the potential of these processors for
production physics processing.Comment: Submitted to proceedings of the 20th International Conference on
Computing in High Energy and Nuclear Physics (CHEP13), Amsterda
Techniques and tools for measuring energy efficiency of scientific software applications
Volume: 608The scale of scientific High Performance Computing (HPC) and High Throughput Computing (HTC) has increased significantly in recent years, and is becoming sensitive to total energy use and cost. Energy-efficiency has thus become an important concern in scientific fields such as High Energy Physics (HEP). There has been a growing interest in utilizing alternate architectures, such as low power ARM processors, to replace traditional Intel x86 architectures. Nevertheless, even though such solutions have been successfully used in mobile applications with low I/O and memory demands, it is unclear if they are suitable and more energy-efficient in the scientific computing environment. Furthermore, there is a lack of tools and experience to derive and compare power consumption between the architectures for various workloads, and eventually to support software optimizations for energy efficiency. To that end, we have performed several physical and software-based measurements of workloads from HEP applications running on ARM and Intel architectures, and compare their power consumption and performance. We leverage several profiling tools (both in hardware and software) to extract different characteristics of the power use. We report the results of these measurements and the experience gained in developing a set of measurement techniques and profiling tools to accurately assess the power consumption for scientific workloads.Peer reviewe
A Roadmap for HEP Software and Computing R&D for the 2020s
Particle physics has an ambitious and broad experimental programme for the coming decades. This programme requires large investments in detector hardware, either to build new facilities and experiments, or to upgrade existing ones. Similarly, it requires commensurate investment in the R&D of software to acquire, manage, process, and analyse the shear amounts of data to be recorded. In planning for the HL-LHC in particular, it is critical that all of the collaborating stakeholders agree on the software goals and priorities, and that the efforts complement each other. In this spirit, this white paper describes the R&D activities required to prepare for this software upgrade.Peer reviewe
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