Snapshot : friend or foe of data management - on optimizing transaction processing in database and blockchain systems

Data management is a complicated task. Due to a wide range of data management tasks, businesses often need a sophisticated data management infrastructure with a plethora of distinct systems to fulfill their requirements. Moreover, since snapshot is an essential ingredient in solving many data management tasks such as checkpointing and recovery, they have been widely exploited in almost all major data management systems that have appeared in recent years. However, snapshots do not always guarantee exceptional performance. In this dissertation, we will see two different faces of the snapshot, one where it has a tremendous positive impact on the performance and usability of the system, and another where an incorrect usage of the snapshot might have a significant negative impact on the performance of the system. This dissertation consists of three loosely-coupled parts that represent three distinct projects that emerged during this doctoral research. In the first part, we analyze the importance of utilizing snapshots in relational database systems. We identify the bottlenecks in state-of-the-art snapshotting algorithms, propose two snapshotting techniques, and optimize the multi-version concurrency control for handling hybrid workloads effectively. Our snapshotting algorithm is up to 100x faster and reduces the latency of analytical queries by up to 4x in comparison to the state-of-the-art techniques. In the second part, we recognize strict snapshotting used by Fabric as a critical bottleneck, and replace it with MVCC and propose some additional optimizations to improve the throughput of the permissioned-blockchain system by up to 12x under highly contended workloads. In the last part, we propose ChainifyDB, a platform that transforms an existing database infrastructure into a blockchain infrastructure. ChainifyDB achieves up to 6x higher throughput in comparison to another state-of-the-art permissioned blockchain system. Furthermore, its external concurrency control protocol outperforms the internal concurrency control protocol of PostgreSQL and MySQL, achieving up to 2.6x higher throughput in a blockchain setup in comparison to a standalone isolated setup. We also utilize snapshots in ChainifyDB to support recovery, which has been missing so far from the permissioned-blockchain world.Datenverwaltung ist eine komplizierte Aufgabe. Aufgrund der vielfältigen Aufgaben im Bereich der Datenverwaltung benötigen Unternehmen häufig eine anspruchsvolle Infrastruktur mit einer Vielzahl an unterschiedlichen Systemen, um ihre Anforderungen zu erfüllen. Dabei ist Snapshotting ein wesentlicher Bestandteil in nahezu allen aktuellen Datenbanksystemen, um Probleme wie Checkpointing und Recovery zu lösen. Allerdings garantieren Snapshots nicht immer eine gute Performance. In dieser Arbeit werden wir zwei Facetten des Snapshots beleuchten: Einerseits können Snapshots enorm positive Auswirkungen auf die Performance und Usability des Systems haben, andererseits können sie bei falscher Anwendung zu erheblichen Performanceverlusten führen. Diese Dissertation besteht aus drei Teilen basierend auf drei unterschiedlichen Projekten, die im Rahmen der Forschung zu dieser Arbeit entstanden sind. Im ersten Teil untersuchen wir die Bedeutung von Snapshots in relationalen Datenbanksystemen. Wir identifizieren die Bottlenecks gegenwärtiger Snapshottingalgorithmen, stellen zwei leichtgewichtige Snapshottingverfahren vor und optimieren Multi- Version Concurrency Control f¨ur das effiziente Ausführen hybrider Workloads. Unser Snapshottingalgorithmus ist bis zu 100 mal schneller und verringert die Latenz analytischer Anfragen um bis zu Faktor vier gegenüber dem Stand der Technik. Im zweiten Teil identifizieren wir striktes Snapshotting als Bottleneck von Fabric. In Folge dessen ersetzen wir es durch MVCC und schlagen weitere Optimierungen vor, mit denen der Durchsatz des Permissioned Blockchain Systems unter hoher Arbeitslast um Faktor zwölf verbessert werden kann. Im letzten Teil stellen wir ChainifyDB vor, eine Platform die eine existierende Datenbankinfrastruktur in eine Blockchaininfrastruktur überführt. ChainifyDB erreicht dabei einen bis zu sechs mal höheren Durchsatz im Vergleich zu anderen aktuellen Systemen, die auf Permissioned Blockchains basieren. Das externe Concurrency Protokoll übertrifft dabei sogar die internen Varianten von PostgreSQL und MySQL und erreicht einen bis zu 2,6 mal höhren Durchsatz im Blockchain Setup als in einem eigenständigen isolierten Setup. Zusätzlich verwenden wir Snapshots in ChainifyDB zur Unterstützung von Recovery, was bisher im Rahmen von Permissioned Blockchains nicht möglich war

Hardware Obfuscation for Finite Field Algorithms

With the rise of computing devices, the security robustness of the devices has become of utmost importance. Companies invest huge sums of money, time and effort in security analysis and vulnerability testing of their software products. Bug bounty programs are held which incentivize security researchers for finding security holes in software. Once holes are found, software firms release security patches for their products. The semiconductor industry has flourished with accelerated innovation. Fabless manufacturing has reduced the time-to-market and lowered the cost of production of devices. Fabless paradigm has introduced trust issues among the hardware designers and manufacturers. Increasing dependence on computing devices in personal applications as well as in critical infrastructure has given a rise to hardware attacks on the devices in the last decade. Reverse engineering and IP theft are major challenges that have emerged for the electronics industry. Integrated circuit design companies experience a loss of billions of dollars because of malicious acts by untrustworthy parties involved in the design and fabrication process, and because of attacks by adversaries on the electronic devices in which the chips are embedded. To counter these attacks, researchers have been working extensively towards finding strong countermeasures. Hardware obfuscation techniques make the reverse engineering of device design and functionality difficult for the adversary. The goal is to conceal or lock the underlying intellectual property of the integrated circuit. Obfuscation in hardware circuits can be implemented to hide the gate-level design, layout and the IP cores. Our work presents a novel hardware obfuscation design through reconfigurable finite field arithmetic units, which can be employed in various error correction and cryptographic algorithms. The effectiveness and efficiency of the proposed methods are verified by an obfuscated Reformulated Inversion-less Berlekamp-Massey (RiBM) architecture based Reed-Solomon decoder. Our experimental results show the hardware implementation of RiBM based Reed-Solomon decoder built using reconfigurable field multiplier designs. The proposed design provides only very low overhead with improved security by obfuscating the functionality and the outputs. The design proposed in our work can also be implemented in hardware designs of other algorithms that are based on finite field arithmetic. However, our main motivation was to target encryption and decryption circuits which store and process sensitive data and are used in critical applications

Myoepithelioma of parotid: an unusual clinical entity with immunohistochemistry

Myoepithelioma was recognized as a histological distinct entity by World Health organization (WHO) in 1991. Only 1% of all salivary gland neoplasms are myoepithelioma. Most commonly affect parotid in approximately 40%. Myoepithelioma is usually a benign tumour arising from neoplastic myoepithelial cells which lack ductal differentiation. The salivary gland tumors in which the ducts comprise less than 5% of the section are classified as myoepitheliomas and in contrast to pleomorphic adenoma myoepithelioma does not show chondroid or osteoid formation. Immunohistochemical analysis can aid in the diagnosis with immunoreactivity to S-100, P63, Calponin, GFAP and myogenic markers. In this report we present a case of myoepithelioma in retroauricular region

E-Commerce in India- A New Perspective

As an advancement in technologies based on Web and Internet, the differences between traditional marketplaces and the world’s e-commerce market—such as corporate capital size, are becoming meaningless. The strategic positioning or a company's ability to identify emerging opportunities and apply the required human skills (such as intellectual resources) to grab them through an e-business strategy that is simple, workable, and practical in today’s business environment and global information scenario and contribute to a new economic environment. E-commerce, when combined with the appropriate strategy and policy approach, allows small and medium-sized firms to compete with large and capital-rich corporations by levelling the playing field. On a different level, emerging countries are allowed wider reach to world’s economy, where they can fight competition with more established economies. Almost all developing countries, if not all, are already involved in electronic commerce, either as manufacturers/sellers or purchasers/customers. However, these countries are having comparatively poor information infrastructure which must be strengthened in order to support e-commerce growth. The following are some of the policy areas where action is needed: Limited credit card availability and a common nationwide credit card system; High cost of Internet access which includes service fees, communication fees, and hosting charges; Poor transportation infrastructure leads to slow and uncertain delivery System; Lack of advance technologies (i.e., an insufficient professional IT workforce) and poor skilled human resources and; Content restrictions based on some public policy and national security, which have a significant impact on businesses in the information services sector, such as the entertainment industries and media; Network security issues and insufficient security safeguards. In this research paper we will try to find out the current scenario of electronic-commerce in India and also look upon the opportunities and challenges in e-commerce in India

Self-organized Nano-lens Arrays by Intensified Dewetting of Electron Beam Modified Polymer Thin-films

Sub-100 nm polymeric spherical plano-convex nano-lens arrays are fabricated using short electron beam exposures to selectively modify the ultrathin (< 30 nm) polymer films, followed by their intensified self-organized dewetting under an aqueous-organic mixture. A short exposure to e-beam locally modifies the polymer chains to effectively change the viscosity of the film in small domains, thus bringing in the dynamical dewetting contrast in the film that produces aligned and ordered dewetted nanostructures. Both negative and positive e-beam tone polymers are thus used to produce array of nano-lenses. The intensified self-organized dewetting under a water-organic solvent mixture overcomes the limitations on surface tension and dewetting force and thus facilitates the formation of sub-100 nm diameter polymer nanolenses of tunable curvature. By varying the extent of e-beam exposure, various configurations from isolated to connected nano-lens arrays can be fabricated.Comment: 16 pages, 8 figure

Intercloud Resource Discovery: A Future Perspective using Blockchain Technology

Intercloud is a single logical entity orchestrating resources from different individual clouds providing on-demand resource provisioning in a seamless manner. However, achieving efficient resource discovery in the intercloud environment remains a challenging task owing to the heterogeneity of resources and diversity of cloud platforms. The paper briefs about intercloud resource discovery, outlines the current work done using existing approaches and examines the challenges involved. Finally, the paper explains the concept of blockchain and presents an innovative conceptual model for efficient resource discovery in intercloud

Acute hepatic failure due to dengue: A case report

Dengue is an arboviral disease endemic in many parts of the world. Although it is known to cause hepatic involvement commonly, it only occasionally results in acute hepatic failure. We present the case of a young male who developed acute hepatic failure due to dengue. The differentials and the management is discussed

A Detailed Overview of Life Cycle Enhancing Approaches for WSN

The major target of a wireless sensor network (WSNs) is to amass related data in the form of packets from the physical world. Transmission of these packets towards lengthier route consumes extra battery, and amplification and causes more intervening. As a result, these variables limit the lifespan of the network and operational ability. Numerous techniques exist in the past to augment the lifespan of the WSN. In this paper we have analyzed state of art techniques which enhance the lifecycle of a WSN