159,584 research outputs found
Software Performance Modeling in PC Clusters
Execution of course grain parallel programs in PC clusters promises super-computer performance in low cost hardware environments. However the overhead associated with data distribution, synchronization, and peripheral access can easily eliminate any performance gain promised by the individual cluster capacity. Application specific system performance analysis is required both to engineer PC cluster hardware and evaluate the cost effectiveness of parallelizing software components. This paper presents a distributed system performance model and software analysis methodology suitable for estimating the execution times of large grain parallel application programs in clusters of PC hardware. The performance model emphasizes the use of application hardware performance results readily available in most systems. These are combined with single thread application software resource requirements in order to estimate the achievable execution rates in target clusters. A case study of the analysis of a video realistic battlefield simulator implementation in a PC cluster running under Linux is presented. Benchmark results and performance estimates for specific candidate hardware configurations are calculated and compared with actual results
Model Exploration Using OpenMOLE - a workflow engine for large scale distributed design of experiments and parameter tuning
OpenMOLE is a scientific workflow engine with a strong emphasis on workload
distribution. Workflows are designed using a high level Domain Specific
Language (DSL) built on top of Scala. It exposes natural parallelism constructs
to easily delegate the workload resulting from a workflow to a wide range of
distributed computing environments. In this work, we briefly expose the strong
assets of OpenMOLE and demonstrate its efficiency at exploring the parameter
set of an agent simulation model. We perform a multi-objective optimisation on
this model using computationally expensive Genetic Algorithms (GA). OpenMOLE
hides the complexity of designing such an experiment thanks to its DSL, and
transparently distributes the optimisation process. The example shows how an
initialisation of the GA with a population of 200,000 individuals can be
evaluated in one hour on the European Grid Infrastructure.Comment: IEEE High Performance Computing and Simulation conference 2015, Jun
2015, Amsterdam, Netherland
Modeling the Internet of Things: a simulation perspective
This paper deals with the problem of properly simulating the Internet of
Things (IoT). Simulating an IoT allows evaluating strategies that can be
employed to deploy smart services over different kinds of territories. However,
the heterogeneity of scenarios seriously complicates this task. This imposes
the use of sophisticated modeling and simulation techniques. We discuss novel
approaches for the provision of scalable simulation scenarios, that enable the
real-time execution of massively populated IoT environments. Attention is given
to novel hybrid and multi-level simulation techniques that, when combined with
agent-based, adaptive Parallel and Distributed Simulation (PADS) approaches,
can provide means to perform highly detailed simulations on demand. To support
this claim, we detail a use case concerned with the simulation of vehicular
transportation systems.Comment: Proceedings of the IEEE 2017 International Conference on High
Performance Computing and Simulation (HPCS 2017
A Change Execution System for Enterprise Services with Compensation Support
Modern enterprises rely on a distributed IT infrastructure to execute their business processes, adopting Service Oriented Architectures in order to improve the flexibility and ease of adaptation of their functions. Nowadays this is a vital characteristic, as the increased competition forces companies to continuously evolve and adapt. SOA applications must be supported by management and deployment systems, which have to continuously apply modifications to the distributed infrastructure. This article presents a modelbased solution for automatically applying change plans to heterogeneous enterprise managed environments. The proposed solution uses models which describe in an abstract language the changes that need to be applied to the environment, and executes all the required operations to the specific managed elements. Also, to ensure that the environment ends in a stable state, compensation for previously executed operations is supported. The validation results from a case study taken from the banking domain are also presented here
Open-TEE - An Open Virtual Trusted Execution Environment
Hardware-based Trusted Execution Environments (TEEs) are widely deployed in
mobile devices. Yet their use has been limited primarily to applications
developed by the device vendors. Recent standardization of TEE interfaces by
GlobalPlatform (GP) promises to partially address this problem by enabling
GP-compliant trusted applications to run on TEEs from different vendors.
Nevertheless ordinary developers wishing to develop trusted applications face
significant challenges. Access to hardware TEE interfaces are difficult to
obtain without support from vendors. Tools and software needed to develop and
debug trusted applications may be expensive or non-existent.
In this paper, we describe Open-TEE, a virtual, hardware-independent TEE
implemented in software. Open-TEE conforms to GP specifications. It allows
developers to develop and debug trusted applications with the same tools they
use for developing software in general. Once a trusted application is fully
debugged, it can be compiled for any actual hardware TEE. Through performance
measurements and a user study we demonstrate that Open-TEE is efficient and
easy to use. We have made Open- TEE freely available as open source.Comment: Author's version of article to appear in 14th IEEE International
Conference on Trust, Security and Privacy in Computing and Communications,
TrustCom 2015, Helsinki, Finland, August 20-22, 201
- …