The Avalon working group will host a presentation by Anthony Simonet on tuesday 28th of february, at 10h30 in amphi J. You are all welcome.
WG
Working Group : iEx.ec, Blockchain-based decentralized Cloud computing platform (by Gilles Fedak)
iEx.ec: Blockchain-based decentralized Cloud computing platform.
date and location : Tuesday 7th February 2017 : Amphi L @ 2PM
WG Hayri Acar: Software development methodology in a Green IT environment
2016-06-07 – Hayri Acar
Title: Software development methodology in a Green IT environment
Speaker: Hayri Acar
Abstract: Writing sustainable, power efficient and green software necessitates understanding the power consumption behavior of a computer program. One of the benefits is the fact that developers, by improving their source code implementations, can optimize power consumption of a software. Existing power consumption models need to be improved by taking into account more components susceptible to consume energy during runtime of an application. In this paper, we first present a detailed classification of previous works on power consumption modelization. Then, we introduce TEEC (Tool to Estimate Energy Consumption) model in order to estimate the power consumed by CPU, memory and disk due to the execution of an application at runtime. The main goal is to guide developers to improve their source code for optimizing energy consumption. TEEC enables determining the part of the code consuming the highest power. This will help to obtain a less energy consuming software with the same functionalities.
WG Philippe Virouleau: Improving OpenMP compilers and runtimes for task-based applications on NUMA architectures
2016-05-17 – Philippe Virouleau
Title: Improving OpenMP compilers and runtimes for task-based applications on NUMA architectures
Speaker: Philippe Virouleau
Abstract: The most popular architecture for building large-scale shared memory machines nowodays is the NUMA architecture (Non-Uniform Memory Access). In such architecture, the shared memory and cores are split in nodes, physically separated from each others. The memory access time depends on which core wants to access which data, and the distance between the core and the data’s NUMA node. A popular application design to efficiently exploit the parallelism offered by large multi processors architectures is to use fine-grain dependent tasks. In order to successfully use this approach on NUMA architectures, the application’s programmer should take great care of the locality between the task being executed, and the data manipulated by the task. OpenMP is the de-facto standard for shared-memory parallel programming, and the revision 4.0 introduced the tasks with dependencies model, in which the programmer can specify which data are read and/or written by a given task. Having the runtime use these informations is a first step to dynamically improve the application’s performances, however more flexibility could be given to the programmer, e.g. by giving him the possibility to specify which data are important for a given task. This presentation will describe my PhD works, which focus on proposing and evaluating compilers and runtimes extensions to help reduce the impact of NUMA architectures on the application’s performances and scalability.
WG Issam Raïs: Towards Green Exascale Computing Challenges
2016-05-03 – Issam Raïs
Title: Towards Green Exascale Computing Challenges
Speaker: Issam Raïs
Abstract: Exascale is coming. Massively heterogeneous machines with hundreds of thousands of computing nodes and each of these nodes possessing hundreds of cores, bounded to each other by a dedicated and efficient network. On every component composing such a machine, we can spot many techniques to reduce energy consumption while maintaining good computing power. In such a context, this presentation aims at presenting the problematics being tackled in the current thesis.
PDF: presentation
WG Hadrien Croubois: Toward an autonomic approach of workflows distribution on cloud
2016-04-19 Hadrien Croubois
Title: Toward an autonomic approach of workflows distribution on cloud ;
Speaker: Hadrien Croubois
Abstract: Advances in distributed systems technologies require a constant rethinking of previous deployments methods. Development of the Cloud paradigm is symptomatic of a broader tendency toward more dynamicity in the management of tasks and resources. However, the scientific computing still mostly uses old paradigms when deploying complex workflows. Our focus is therefore to propose a solution that will make the link between the needs of user in terms of scientific computation and the features offered by cloud providers. After having modelled both those needs and features, we describe the different mechanisms which are part of what should allow for an autonomous platform dedicated to collaborative scientific computing.
PDF: slides
WG Issam Raïs: An analysis of the feasibility of energy harvesting with thermoelectric generators on petascale and exascale systems
2016-04-16 Issam Raïs
Title: An analysis of the feasibility of energy harvesting with thermoelectric generators on petascale and exascale systems;
Speaker: Issam Raïs
Abstract: The heat induced by computing resources is generally a waste of energy in supercomputers. This is especially true in very large scale supercomputers, where the produced heat has to be compensated with expensive and energy consuming cooling systems. An analysis of the feasibility of energy harvesting with thermoelectric generators on petascale and exascale systems; Energy is a critical point for future supercomputing trends that currently try to achieve exascale, without having its energy consumption reaching an important fraction of a nuclear power plant. Thus, new ways of generating or recovering energy have to be explored. Energy harvesting consists in recovering wasted energy. ThermoElectric Generators (TEGs) aim to recover energy by converting wasted dissipated energy into usable electricity. By combining computing units (CU) and TEGs at very large scale, we spotted a potential way to recover energy from wasted heat generated by computations on supercomputers. In this paper, we study the potential gains in combining TEGs with computational units at petascale and exascale. We present the technology behind TEGs, the study of a typical supercomputer environment, and finally our results concerning binding TEGs and computational units in a petascale and exascale system. With the available technology, we demonstrate that the use of TEGs in a supercomputer environment could be realistic and quickly profitable, and hence have a positive environmental impact.
PDF: Thermoelectricity
WG Romaric Guilier: E-Biothon
2016-03-29 Romaric Guillier
Title: E-Biothon
Speaker: Romaric Guillier.
Abstract: an experimental platform for BioInformatics; Abstract: The E-Biothon platform is an experimental Cloud platform to help speed up and advance research in biology, health and environment. It is based on a Blue Gene/P system and a web portal that allow members of the bioinformatics community to easily launch their scientific applications. This presentation describes the technical capacities of the platform, the different applications supported and finally a set of user experiences on the platform.
PDF: ebiothon_presentation_avalon
Hadrien Croubois : Detecting Silent Data Corruption Using an Auxiliary Method and External Observer
Title: Detecting Silent Data Corruption Using an Auxiliary Method and External Observer
Speaker: Hadrien Croubois
Abstract: HPC platforms and application are becoming increasingly complex. Consequently, protecting results against all forms of corruption and ensuring trustworthiness are becoming more important. While previous work focuses on application-specific detectors, the dataflow manager in our current work in the Decaf project aims to have an efficient generic mechanism. We address those issues using new replication patterns that rely on the use of an auxiliary method and an external learning observer. In this talk, we present both the theoretical validation mechanisms and different use cases where our mechanism can be applied to detect silent data corruption.
Sonia Ben Mokhtar : Building Selfish-Resilient Distributed Systems
Title : Building Selfish-Resilient Distributed Systems
Speaker: Sonia Ben Mokhtar
Abstract: Collaborative systems (e.g., peer-to-peer instant messaging, file sharing, live streaming applications) generate among the largest amounts of traffic of today’s Internet. Common to all these systems is the assumption that, in return to the service offered by the collaborative system, users are willing to participate by sharing their resources with others. However, in practice, these systems suffer from selfish users that strategically free-ride the system whenever it is convenient for them. Albeit a number of solutions have been devised in the literature to deal with this problem, most of them are tailored to specific systems and thus lack flexibility and re-usability. During this seminar I will discuss methods for building selfish resilient distributed systems and future directions towards the automatic transformation of a given collaborative system into a system resilient to selfish behaviors.