A preliminary study of the impact of software engineering on GreenIT

International audienceGreenIT has emerged as a discipline concerned with the optimization of software solutions with regards to their energy consumption. In this domain, most of state-of-the-art solutions offer limited or constraining approaches to monitor the energy consumption of a device or a process. In this paper, we therefore report on a runtime energy monitoring framework we developed to easily report on the energy consumption of system processes. Concretely, our approach adopts an OS-level library, called POWERAPI, which estimates the power consumption of processes according to different dimensions (CPU, network, etc.). In order to better understand potential energy leaks of legacy software, we use this library to study the impact of programming languages and algorithmic choices on the energy consumption. This preliminary study is based on an empirical evaluation of a eight implementations of the Towers of Hanoi problem

Towards an Integrated Full-Stack Green Software Development Methodology

Existing green/eco responsible approaches for IT are frequently domain-specific and very focused on one topic. For example, some works are focused on saving energy with better virtual machine management on cloud infrastructures or data management in wireless sensor networks, in order to minimize the data transfers and sensors’ wakeups. Nevertheless, they consider only limited aspects in the whole software development process; indeed, very few researches propose a global approach. In this context, we envision a green development methodology that approaches energy saving aspects from the design phase and at all the system layers (software, hardware, user requirements, execution contexts, etc.), which can provide positive leverage as well as avoid side effects (one decision can be positive at one system layer but may trigger negative impact on other layers). We motivate the interest of this vision and describe key ideas regarding how to address these considerations in the development methodology

Maturity model based on CMMI for governance and management of Green IT

Sustainability is a problem that is increasingly worrying organisations around the world, which has led them to adopt sustainable practices in their processes. From the point of view of one of the areas that have had the greatest impact in recent times in organisations, the area of information technology (IT), different sustainable practices have arisen in isolation, known as Green IT practices. So, a framework that organises and establishes these practices (until now isolated) is necessary in order to implement, assess, and improve the Green IT in organisations in an efficient, gradual, and integrated way. In this study, the authors propose a maturity model based on capability maturity model integration (CMMI), through which it is intended to help organisations gradually implement and improve through different levels of maturity, the governance and management of Green IT. The validations of this proposal carried out through experts and practical cases demonstrate the usefulness of this proposal when implementing, assessing, and improving the Green IT in organisations

Improving the Energy Efficiency of Software Systems for Multi-Core Architectures

International audienceThe ICT has an huge impact on the world CO2 emissions and recent study estimates its account to 2% of these emissions. This growing account emissions makes IT energy efficiency an important challenge. State-of-the-art has proven that the processor is the main power consumer. Processor are nowadays more and more complex and they are used in many hardware systems, such as computers or smart-phones. This thesis is thus focusing on the software energy efficiency for multi-core systems. In this paper, we therefore report our motivations to understand deeply their architectures for improving their energy efficiencies. Manufacturers have worked tremendously to improve performance and reduce power consumption of their processors. However a lot of things remains to do in the software side. We claim that energy-efficient softwares can play a deterministic role to reduce the IT carbon footprint. To answer this challenge, we are believing on the software-metric approach with a minimal hardware investment. For this purpose, an efficient, scalable and non-invasive tool is needed. As a result, we created PowerAPI, to provide fine-grained power estimations at process and code-level for optimizing the software energy efficiency automatically. This solution will help to identify clearly the energy leaks for optimizing automatically the power consumed by software

Towards a Green and Sustainable Software

International audienceInformation and Communication Technologies (ICTs) are responsible around 2% of worldwide greenhouse gas emissions [1]. On the other hand, the use of mobile devices (smartphone, tablet, etc.) is continually increasing. Due to the accessibility of the Internet and the cloud computing, users will use more and more software applications which will cause even an increasing effect on gas emission. Thus, an important research question is "how can we reduce or limit the energy consumption related to ICT and, in particular, related to software?" For a long time, proposed solutions focused only on the hardware design, however in recent years the software aspects have also become important. Our first objective is to compare the studies in the research area of energy efficient/green software. Relying on this survey, we will propose a methodology to measure the energy consumed by software at runtime

Beyond CPU: Considering Memory Power Consumption of Software

International audienceICTs (Information and Communication Technologies) are responsible around 2% of worldwide greenhouse gas emissions (Gartner, 2007). And according to the Intergovernmental Panel on Climate Change (IPPC) recent reports, CO2 emissions due to ICTs are increasing widely. For this reason, many works tried to propose various tools to estimate the energy consumption due to software in order to reduce carbon footprint. However, these studies, in the majority of cases, takes into account only the CPU and neglects all others components. Whereas, the trend towards high-density packaging and raised memory involve a great increased of power consumption caused by memory and maybe memory can become the largest power consumer in servers. In this paper, we model and then estimate the power consumed by CPU and memory due to the execution of a software. Thus, we perform several experiments in order to observe the behavior of each component

VihreäIT metriikoiden analysointi sekä mittausviitekehyksen luonti Sonera Helsinki Datakeskus (HDC) projektille.

The two objectives of this thesis were to investigate and evaluate the most suitable set of energy efficiency metrics for Sonera Helsinki Data Center (HDC), and to analyze which energy efficient technologies could be implemented and in what order to gain most impact. Sustainable IT is a complex matter, and it has two components. First and the more complex matter is the energy efficiency and energy-proportionality of the IT environment. The second is the use of renewable energy sources. Both of these need to be addressed. This thesis is a theoretical study, and it focuses on energy efficiency. The use of off-site renewables is outside of the scope of this thesis. The main aim of this thesis is to improve energy efficiency through effective metric framework. In the final metric framework, metrics that target renewable energy usage in the data center are included as they are important from CO2 emission reduction perspective. The selection of energy efficient solutions in this thesis are examples from most important data center technology categories, and do not try to cover the whole array of different solutions to improve energy efficiency in a data center. The ontological goal is to present main energy efficiency metrics available in scientific discourse, and also present examples of energy efficient solutions in most energy consuming technology domains inside the data center. Even though some of the concepts are quite abstract, realism is taken into account in every analysis. The epistemology in this thesis is based on scientific articles that include empirical validation and scientific peer review. This forms the origin of the used knowledge and the nature of this knowledge. The findings from this thesis are considered valid and reliable based on the epistemology of scientific articles, and by using the actual planning documents of Sonera HDC. The reasoning in this thesis is done in abstracto, but there are many empirical results that qualify the results also as ´in concreto´. Findings are significant for Sonera HDC but they are also applicable for any general data center project or company seeking energy efficiency in their data centers.Lopputyöllä on kaksi päätavoitetta. Ensimmäinen tavoite on löytää sopivin mittausviitekehys energiatehokkuuden osoittamiseksi Sonera Helsinki Datakeskukselle (HDC). Toisena tavoitteena on analysoida, mitä energiatehokkaita ratkaisuja tulisi implementoida ja missä järjestyksessä, saavuttaakseen mahdollisimman ison vaikutuksen. Vihreä IT on monimutkainen asia ja samalla siihen liittyy kaksi eri komponenttia. Ensimmäisenä komponenttina, ja merkityksellisempänä sekä monimutkaisempana, on energiatehokkuus ja energian kulutuksen mukautuvuus suhteessa työkuormaan. Toinen komponentti vihreän IT:n osalta on uusiutuvien energialähteiden käyttäminen. Molemmat komponentit on huomioitava. Lopputyö on teoreettinen tutkimus. Lopputyön ontologinen tavoite on esittää keskeisimmät energiatehokkuusmittarit, jotka ovat saatavilla tieteellisessä keskustelussa, ja esittää myös esimerkkejä energiatehokkaista ratkaisuista teknologia-alueisiin, jotka kuluttavat eniten energiaa data keskuksissa. Vaikka osa esitetyistä ratkaisuista on melko abstraktissa todellisuudessa, realismi on pyritty ottamaan huomioon arvioita tehdessä. Epistemologisesti tämä lopputyö perustuu tieteellisiin artikkeleihin, joissa on tehty empiiristä validointia ja tiedeyhteisön vertaisarviointia tiedon totuusarvosta. Kirjoittaja pyrkii välttämään oman arvomaailman ja subjektiivisen näkemyksen tuomista analyysiin pyrkimällä enemmänkin arvioimaan ratkaisuja perustuen päätavoitteeseen, joka on sekä lisätä energiatehokkuutta että vähentää CO2 -päästöjä datakeskuksessa. Lopputyön löydökset todetaan valideiksi ja luotettaviksi, koska ne perustuvat tieteellisten artikkeleiden epistemologiaan ja siihen, että arvioinnin pohjana on käytetty todellisia Sonera HDC -projektin suunnitteludokumentteja. Päätelmät ja analyysit ovat abstrahoituja, mutta perustuvat empiirisiin tuloksiin, jotka koskevat käytännön tekemistä sekä valintoja. Löydökset ovat merkittäviä Sonera HDC -projektin kannalta, ja myös muille datakeskuksille, jotka haluavat toimia kestävän kehityksen pohjalta

Unit Testing of Energy Consumption of Software Libraries

International audienceThe development of energy-efficient software has become a key requirement for a large number of devices, from smartphones to data centers. However, measuring accurately this consumption is a major challenge that state-of-the-art approaches have tried to tackle with a limited success. While monitoring applications' consumption offers a clear insight on where the energy is being spent, it does not help in understanding how the energy is consumed. In this paper, we therefore introduce Jalen Unit, a software framework that infers the energy consumption model of software libraries from execution traces. This model can then be used to diagnose application code for detecting energy bugs, understanding energy distribution, establishing energy profiles and classifications, and comparing software libraries against their energy consumption

Valgreen: an Application's Energy Profiler

International audienceThe popularity of hand-held and portable devices put the energy aware computing in evidence. The need for long time batteries surpasses the hardware manufacturer, impacting the operational system policies and software development. Power modeling of applications has been studied during the last years and can be used to estimate their total energy. In order to aid the programmer to implement energy efficient algorithms, this paper introduces an application's energy profiler, namely Valgreen, which exploits the battery's information in order to generate an architecture independent power model through a calibration process

A framework of green it capability maturity for it product lifecycle in UTM

In the last few decades, Information and Communication Technology (ICT) has featured prominently in transforming business practices. It has redefined our social existence. A huge number of IT devices such as computers, monitors, printers, scanners, copiers and fax machines, digital duplicators, multi-function devices, and mailing machines are increasingly produced everyday to support and fulfill operational needs of the organization. These IT devices contribute to global warming by producing CO2 emissions and contributing to the greenhouse effect. This is due to the fact that all phases on the IT product lifecycle produces an environmental impact. This research develops a green IT framework to implement and sustain green IT implementation and to apply this framework to UTM faculties/unit to assess the current capability maturity level of green IT practices for IT product lifecycle. The framework covers the green IT best practices in three phases of IT product lifecycle, namely procurement, usage, reuse/disposal, and the level of capability maturity. The framework was developed by reviewing previous green IT capability maturity frameworks and green IT best practices of IT product lifecycle. The framework was then verified using online card-sorting and interviews with three experts, namely IT and lab managers. The framework provides UTM faculties/unit with a holistic guideline to implement and sustain green IT practices throughout the IT product lifecycle with the help of capability maturity level; level 1 is the initial level, and level 5 is the optimal level. The framework was applied to four UTM faculties and the School of Postgraduate Studies to assess their current capability maturity level of green IT practices for IT product lifecycle