scholarly journals Hybrid HDFS: decreasing energy consumption and speeding up Hadoop using SSDs

Author(s):  
Ivanilton Polato ◽  
Denilson Barbosa ◽  
Abram Hindle ◽  
Fabio Kon

Apache Hadoop has evolved significantly over the last years, with more than 60 releases bringing new features. By implementing the MapReduce programming paradigm and leveraging HDFS, its distributed file system, Hadoop has become a reliable and fault tolerant middleware for parallel and distributed computing over large datasets. Nevertheless, Hadoop may struggle under certain workloads, resulting in poor performance and high energy consumption. Users increasingly demand that high performance computing solutions being to address sustainability and limit power consumption. In this paper, we introduce HDFSH, a hybrid storage mechanism for HDFS, which uses a combination of Hard Disks and Solid-State Disks to achieve higher performance while saving power in Hadoop computations. HDFSH brings to middleware the best from HDs (affordable cost per GB and high storage capacity) and SSDs (high throughput and low energy consumption) in a configurable fashion, using dedicated storage zones for each storage device type. We implemented our mechanism as a block placement policy for HDFS, and assessed it over six recent releases of the Hadoop project, representing different designs of the Hadoop middleware. Results indicate that our approach increases overall job performance while decreasing the energy consumption under most hybrid configurations evaluated. Our results also showed that in many cases storing only part of the data in SSDs results in significant energy savings and execution speedups.

2015 ◽  
Author(s):  
Ivanilton Polato ◽  
Denilson Barbosa ◽  
Abram Hindle ◽  
Fabio Kon

Apache Hadoop has evolved significantly over the last years, with more than 60 releases bringing new features. By implementing the MapReduce programming paradigm and leveraging HDFS, its distributed file system, Hadoop has become a reliable and fault tolerant middleware for parallel and distributed computing over large datasets. Nevertheless, Hadoop may struggle under certain workloads, resulting in poor performance and high energy consumption. Users increasingly demand that high performance computing solutions being to address sustainability and limit power consumption. In this paper, we introduce HDFSH, a hybrid storage mechanism for HDFS, which uses a combination of Hard Disks and Solid-State Disks to achieve higher performance while saving power in Hadoop computations. HDFSH brings to middleware the best from HDs (affordable cost per GB and high storage capacity) and SSDs (high throughput and low energy consumption) in a configurable fashion, using dedicated storage zones for each storage device type. We implemented our mechanism as a block placement policy for HDFS, and assessed it over six recent releases of the Hadoop project, representing different designs of the Hadoop middleware. Results indicate that our approach increases overall job performance while decreasing the energy consumption under most hybrid configurations evaluated. Our results also showed that in many cases storing only part of the data in SSDs results in significant energy savings and execution speedups.


Author(s):  
Arun Unnikrishnan ◽  
P. V. M. Rao

Continuous need to increase productivity and reliability in machining has led to high-performance machines that are often characterized by high energy demands. As a result, energy minimization is identified as one of the key goals in machining. With the availability of improved predictive models for energy estimation in machining, energy-conscious process planning for machining is now possible. The present work focuses on the assessment of process plans of machined parts from energy consumption point of view. An experimentally validated model for energy estimation is first presented. Using this model two important process planning variables on energy consumption in machining has been studied. Firstly selection of tool paths including curvilinear tool paths has been considered from energy consumption point of view. Secondly, strategies for the selection of cutting parameters for roughing, semi-finishing and finishing from energy consumption perspective are discussed.


2017 ◽  
Vol 41 (17) ◽  
pp. 9024-9032 ◽  
Author(s):  
Enke Feng ◽  
Hui Peng ◽  
Zhiguo Zhang ◽  
Jindan Li ◽  
Ziqiang Lei

As-fabricated foldable solid-state supercapacitors are suitable for highly fold-tolerant high-energy-density energy storage device applications.


2018 ◽  
Vol 77 (9) ◽  
pp. 2242-2252 ◽  
Author(s):  
M. Vaccari ◽  
P. Foladori ◽  
S. Nembrini ◽  
F. Vitali

Abstract One of the largest surveys in Europe about energy consumption in Italian wastewater treatment plants (WWTPs) is presented, based on 241 WWTPs and a total population equivalent (PE) of more than 9,000,000 PE. The study contributes towards standardised resilient data and benchmarking and to identify potentials for energy savings. In the energy benchmark, three indicators were used: specific energy consumption expressed per population equivalents (kWh PE−1 year−1), per cubic meter (kWh/m3), and per unit of chemical oxygen demand (COD) removed (kWh/kgCOD). The indicator kWh/m3, even though widely applied, resulted in a biased benchmark, because highly influenced by stormwater and infiltrations. Plants with combined networks (often used in Europe) showed an apparent better energy performance. Conversely, the indicator kWh PE−1 year−1 resulted in a more meaningful definition of a benchmark. High energy efficiency was associated with: (i) large capacity of the plant, (ii) higher COD concentration in wastewater, (iii) separate sewer systems, (iv) capacity utilisation over 80%, and (v) high organic loads, but without overloading. The 25th percentile was proposed as a benchmark for four size classes: 23 kWh PE−1 y−1 for large plants > 100,000 PE; 42 kWh PE−1 y−1 for capacity 10,000 < PE < 100,000, 48 kWh PE−1 y−1 for capacity 2,000 < PE < 10,000 and 76 kWh PE−1 y−1 for small plants < 2,000 PE.


2021 ◽  
Vol 6 (2) ◽  
pp. 03-17
Author(s):  
Gazal Dandia ◽  
◽  
Pratheek Sudhakaran ◽  
Chaitali Basu ◽  
◽  
...  

Introduction: High energy consumption by buildings is a great threat to the environment and one of the major causes of climate change. With a population of 1.4 billion people and one of the fastest-growing economies in the world, India is extremely vital for the future of global energy markets. The energy demand for construction activities continues to rise and it is responsible for over one-third of global final energy consumption. Currently, buildings in India account for 35% of total energy consumption and the value is growing by 8% annually. Around 11% of total energy consumption are attributed to the commercial sector. Energy-efficient retrofitting of the built environments created in recent decades is a pressing urban challenge. Presently, most energy-efficient retrofit projects focus mainly on the engineering aspects. In this paper, we evaluate various retrofitting options, such as passive architectural interventions, active technological interventions, or a combination of both, to create the optimum result for the selected building. Methods: Based on a literature study and case examples, we identified various energy-efficient retrofit measures, and then examined and evaluated those as applied to the case study of Awas Bhawan (Rajasthan Housing Board Headquarters), Jaipur, India. For the evaluation, we developed a simulation model using EQuest for each energy measure and calculated the resultant energy savings. Then, based on the cost of implementation and the cost of energy saved, we calculated the payback period. Finally, an optimum retrofit solution was formulated with account for the payback period and ease of installation. Results and discussion: The detailed analysis of various energy-efficient retrofit measures as applied to the case study indicates that the most feasible options for retrofit resulting in optimum energy savings with short payback periods include passive architecture measures and equipment upgrades.


Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2218
Author(s):  
Francisco J. Rey Martínez ◽  
Julio F. San José Alonso ◽  
Eloy Velasco Gómez ◽  
Ana Tejero González ◽  
Paula M Esquivias ◽  
...  

The high energy consumption of cooling systems justifies the need for strategies to increase the efficiency of the facilities, in order to reduce the related CO2 emissions. This study aims to improve the performance and reduce the energy consumption of an 8.6 MW air cooled chiller. This installed capacity is biased due to the screw compressors, of 2.98 Energy Efficiency Ratio (EER) at full load (characteristics provided by the manufacturer). The chiller unit has been modified by placing evaporating cooling pads before the condensing coils. The chiller has been monitored for three months, recording over 544,322 measurements (5 min-step data), with and without the evaporative cooling pads, to assess the performance. Data comparison has been done by selecting two days (with and without evaporative panels) with the same health care load and temperatures. Implementing the proposed strategy yields an improvement in the European Seasonal Energy Efficiency Ratio (ESEER) from 3.69 to 4.83, while the Total Equivalent Warming Impact (TEWI) decreases about 1000 tCO2. Energy savings of up to 32.6 MWh result into a payback period lower than 2 years.


Buildings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 21 ◽  
Author(s):  
Khadija Jnat ◽  
Isam Shahrour ◽  
Ali Zaoui

Energy consumption in the social housing sector constitutes a major economic, social, and environmental issue, because in some countries such as France, social housing accounts for about 19% of the housing sector. In addition, this sector suffers from ageing, which results in high energy consumption, deterioration in the occupant quality of life, and high pressure on the budget of low-income occupants. The reduction of the energy consumption in this sector becomes a “must”. This reduction can be achieved through energy renovation and innovation in both energy management and occupant involvement by using smart technology. This paper presents a contribution to this goal through the investigation of the impact of smart monitoring on energy savings. The research is based on monitoring of comfort conditions in an occupied social housing residence in the North of France and the use of building thermal numerical modeling. Results of monitoring show that the indoor temperature largely exceeds the regulations requirements and the use of a smart system together with occupant involvement could lead to significant savings in heating energy consumption. The novelty in this paper concerns the use of comfort data from occupied social housing residence, occupation conditions, and building thermal modeling to estimate energy savings. The proposed methodology could be easily implemented to estimate heating energy savings in social housing buildings that lack individual energy consumption monitoring.


2020 ◽  
Vol 15 (1) ◽  
pp. 147-153
Author(s):  
Yucai Li ◽  
Yan Zhao ◽  
Dong Zhang ◽  
Shiwei Song ◽  
Jian Wang ◽  
...  

Electrochemical performance of the electrode materials is seriously dependent on the structure and morphology of the electrode material. In this work, the nanoflower-like Co3O4 samples are successfully prepared on Ni foam via a facile hydrothermal method. The as-fabricated Co3O4 samples exhibit superior electrochemical performance with a high specific capacitance of 382.6 C g-1 at 1 A g-1 and excellent capacitance retention. In addition, the as-fabricated device presents a high energy density of 23.6 Wh kg-1 at a power density of 508.6 W kg-1 and excellent cycle stability with a capacitance retention of 81.2% after 10000 cycles, indicating a promising application as electrodes for energy storage device.


2020 ◽  
Vol 12 (4) ◽  
pp. 1654 ◽  
Author(s):  
Abdelhakim Mesloub ◽  
Ghazy Abdullah Albaqawy ◽  
Mohd Zin Kandar

Recently, Building Integrated Photovoltaic (BIPV) windows have become an alternative energy solution to achieve a zero-energy building (ZEB) and provide visual comfort. In Algeria, some problems arise due to the high energy consumption levels of the building sector. Large amounts of this energy are lost through the external envelope façade, because of the poorness of the window’s design. Therefore, this research aimed to investigate the optimum BIPV window performance for overall energy consumption (OEC) in terms of energy output, heating and cooling load, and artificial lighting to ensure visual comfort and energy savings in typical office buildings under a semi-arid climate. Field measurements of the tested office were carried out during a critical period. The data have been validated and used to develop a model for an OEC simulation. Extensive simulations using graphical optimization methods are applied to the base-model, as well as nine commercially-available BIPV modules with different Window Wall Ratios (WWRs), cardinal orientations, and tilt angles. The results of the investigation from the site measurements show a significant amount of energy output compared to the energy demand. This study revealed that the optimum BIPV window design includes double-glazing PV modules (A) with medium WWR and 20% VLT in the southern façade and 30% VLT toward the east–west axis. The maximum energy savings that can be achieved are 60% toward the south orientation by double-glazing PV module (D). On the other hand, the PV modules significantly minimize the glare index compared to the base-model. The data extracted from the simulation established that the energy output percentages in a 3D model can be used by architects and designers in early stages. In the end, the adoption of optimum BIPV windows shows a significant enough improvement in their overall energy savings and visual comfort to consider them essential under a semi-arid climate.


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