Energy Efficient Disaggregated Servers for Future Data Centers

With the dawn of cloud computing, data centers’ power consumption has received increased attention. In this paper we evaluate the energy efficiency potential of exploiting the concept of Disaggregated Server (DS) design in data centers for efficient resource provisioning. A DS, is a new approach for future racks where servers are disaggregated and resources, such as processors, memory and IO ports are arranged in resource pools constructing processing pools, memory pools and IO pools. We developed a mixed integer linear programming (MILP) model for energy minimization of the virtual machine (VM) placement problem in data centres implementing DS approach. The results show that the average power savings are up to 49% for the different VM types considered

Future Energy Efficient Data Centers With Disaggregated Servers

The popularity of the Internet and the demand for 24/7 services uptime is driving system performance and reliability requirements to levels that today's data centers can no longer support. This paper examines the traditional monolithic conventional server (CS) design and compares it to a new design paradigm: the disaggregated server (DS) data center design. The DS design arranges data centers resources in physical pools, such as processing, memory, and IO module pools, rather than packing each subset of such resources into a single server box. In this paper, we study energy efficient resource provisioning and virtual machine (VM) allocation in DS-based data centers compared to CS-based data centers. First, we present our new design for the photonic DS-based data center architecture, supplemented with a complete description of the architectural components. Second, we develop a mixed integer linear programming (MILP) model to optimize VM allocation for the DS-based data center, including the data center communication fabric power consumption. Our results indicate that, in DS data centers, the optimum allocation of pooled resources and their communication power yields up to 42% average savings in total power consumption when compared with the CS approach. Due to the MILP high computational complexity, we developed an energy efficient resource provisioning heuristic for DS with communication fabric (EERP-DSCF), based on the MILP model insights, with comparable power efficiency to the MILP model. With EERP-DSCF, we can extend the number of served VMs, where the MILP model scalability for a large number of VMs is challenging. Furthermore, we assess the energy efficiency of the DS design under stringent conditions by increasing the CPU to memory traffic and by including high noncommunication power consumption to determine the conditions at which the DS and CS designs become comparable in power consumption. Finally, we present a complete analysis of the communication patterns in our new DS design and some recommendations for design and implementation challenges

Greening Big Data Networks: Volume Impact

Tremendous volumes generated by big data applications are starting to overwhelm data centers and networks. Traditional research efforts have determined how to process these vast volumes of data inside datacenters. Nevertheless, slight attention has addressed the increase in power consumption resulting from transferring these gigantic volumes of data from the source to destination (datacenters). An efficient approach to address this challenge is to progressively processing large volumes of data as close to the source as possible and transport the reduced volume of extracted knowledge to the destination. In this article, we examine the impact of processing different big data volumes on network power consumption in a progressive manner from source to datacenters. Accordingly, a noteworthy decrease for data transferred is achieved which results in a generous reduction in network power consumption. We consider different volumes of big data chunks. We introduce a Mixed Integer Linear Programming model (MILP) to optimize the processing locations of these volumes of data and the locations of two datacenters. The results show that serving different big data volumes of uniform distribution yields higher power saving compared to the volumes of chunks with fixed size. Therefore, we obtain an average network power saving of 57%, 48%, and 35% when considering the volumes of 10-220 (uniform) Gb, 110 Gb, and 50 Gb per chunk, respectively, compared to the conventional approach where all these chunks are processed inside datacenters only

Energy Efficient Resource Provisioning with VM Migration Heuristic for Disaggregated Server Design

This article introduces an energy efficient heuristic that performs resource provisioning and Virtual Machine (VM) migration in the Disaggregated Server (DS) schema. The DS is a promising paradigm for future data centers where servers’ components are disaggregated at the hardware unit levels and resources of similar type are combined in type respective pools, such as processing pools, memory pools and IO pools. We examined 1000 VM requests that demand various processing, memory and IO requirements. Requests have exponentially distributed inter arrival time and with uniformly distributed service duration periods. Resources occupied by a certain VM are released when the VM finishes its service duration. The heuristic optimises VMs allocation and dynamically migrates existing VMs to occupy newly released energy efficient resources. We assess the energy efficiency of the heuristic by applying increasing service duration periods. The results of the numerical simulation indicate that our power savings can reach up to 55% when compared to our previous study where VM service duration is infinite and resources are not released

Investigation of Genetic Diversity of Wilsonomyces carpophilus in Khorasan Razavi Using rep-PCR Marker

Introduction: Shot hole disease of stone fruit trees resulted from Wilsonomyces carpophilus can weaken the trees and reduce the quantity and quality of the crops worldwide particularly in semi-arid regions. Coryneum blight or shot hole disease infects all the stone fruit trees including peach, nectarine, apricot, sour cherry, plum, cherry, and almond. One of the most important strategies to manage any plant disease is to use resistant cultivars. In this way, it is very important to have knowledge about the status of genetic diversity and to determine the relationship between isolates of the causal agent fungus. The main objective of the present research was to study the genetic diversity of W. carpophilus in Khorasan Razavi province using the rep-PCR molecular fingerprinting method. Materials and Methods: Sampling was performed from peach, nectarine, plum, apricot and cherry orchards of Quchan, Torqabeh, Shandiz, Chenaran, Neishabur, Kalat, Torbat Heidarieh and Mashhad during spring and summer of 2012 and 2013. Mono-conidial isolates were recovered from infected leaves, fruits, and twigs of different parts of orchards. Infected collected leaves, twigs, and fruits were transferred to the laboratory. By using techniques of Klimesova and Prasil (1989) and Mehta (1998) from the cut parts between infected and healthy tissues of each isolate, cuts of 2-3 mm from leaf, fruit and twig were prepared by the scalpel. These pieces were surface sterilized with 1% sodium hypochlorite liquid about 1 to 3 minutes based on the thickness of tissue. Then, the samples were cultured on PDA, MEA, and WA media and incubated at 18, 20, and 25 °C. The isolated fungi were purified and identified. The research was performed on 20 fungal isolates collected from different stone fruit trees. Genomic DNA was amplified using BOX A1R, ERIC2, ERIC1R, REP2-I, and REP1R-I primers. Thirty-eight of 39 fragments amplified were polymorphic for 100 to 5000 base pairs. Similarity matrix between isolates was calculated based on Jacquard Coefficient and cluster analysis and construction of dendrogram were done based on UPGM using NTYSIS.PC 2.0 software. Results and discussion: From 39 amplified bands, 38 bands (97.5%) showed polymorphism. The molecular weight of amplified DNA fragments was between 100 to 5000 bp. Based on analysis of banding pattern of REP primer set, isolates of W. carpophilus were categorized into 12 groups at the 69% similarity level. The most genetic similarity of isolates (94%) was between AK (apricot of Kalat) and PK (peach of Kalat) and the least genetic similarity of W. carpophilus isolates was between AQ (apricot of Quchan), AN (apricot of Neishabur), AC (apricot of Chenaran), PlM (plum of Mashhad), PM2 (peach of Mashhad number 2), and CC (cherry of Chenaran) with the other isolates. Based on the results of this study rep-PCR could separate isolates of W. carpophilus very well and also could separate similar isolates and hosts which have the close genetic relationship. Similar results were obtained by Edel et al. (1995) and Jedryczka et al. (1999). Edel et al. (1995) compared three different molecular methods for characterization of Fusarium oxysporum strains. The marker also separated isolates of Kalat and Chenaran geographically and to some extent isolates of plum in terms of hosting from the other isolates. Toda et al. (1999) in their study, about the investigation of genetic correlation among and within different isolates of Rhizoctonia solani by rep-PCR divided the 41 isolates into 7 groups which indicate considerable genetic diversity among isolates. Also, Karimi et al. (2010) in their study about the investigation of genetic diversity of Sclerotinia sclerotiorum at 64% similarity level, divided the isolates into 7 groups and separated most of the isolates geographically. Conclusion: The results obtained in this study indicated that rep-PCR is a practical, rapid, and accurate technique for separation of W. carpophilus isolates. Considering the high genetic diversity observed in the population of this fungus, making attempts to plant cultivars with high resistance and resistant genes can largely prevent the outbreaks and intensity of the pathogen. Therefore, further researches in this area can be placed in breeding, production and reproduction of cultivars with particular resistance programs against shot hole disease. The present research study is a prelude to solving problems related to this important disease