Universität Stuttgart
Permanent URI for this communityhttps://elib.uni-stuttgart.de/handle/11682/1
Browse
Search Results
Item Open Access Optimizing the efficiency of data-intensive Data Mashups using Map-Reduce(2017) Sarangi, SunayanaIn order to derive knowledge and information from data through data processing, data integration and data analysis, a variety of Data Mashup tools have been developed in the past. Data Mashups are pipelines that process and integrate data based on different interconnected operators that realize data operations such as filter, join, extraction, alteration or integration. The overall goal is to integrate data from different sources into a single one. Most of these Mashup tools offer a grahical modeling platform, enabling the users to model the data sources, data operations and the data flow, thus, creating a so called Mashup Plan. This enables non-IT experts to perform data operations without having to deal with their technical details. Further, by allowing easy re-modeling and re-execution of the Mashup Plan, it also allows an iterative and explorative trial-an-error integration to enable real time insights into the data. These existing Data Mashup tools are efficient in executing small size data sets, however, they do not emphasize on the run-time efficiency of the data operations. This work is motivated by the limitations of current Data Mashup approaches with regard to data-intensive operations. The run-time of a data operation majorly varies depending on the size of the input data. Hence, in scenarios where one data operation expects inputs from multiple Data Mashup pipelines, which are executed in parallel, a data intensive operation in one of the Data Mashup pipelines leads to a bottleneck, thereby delaying the entire process. The efficiency of such scenarios can be greatly improved by executing the data-intensive operations in a distributed manner. This master thesis copes with this issue through an efficiency optimization of pipeline operators based on Map-Reduce. The Map-Reduce approach enables distributed processing of data to improve the run-time. Map-Reduce is divided into two main steps: (i) the Map step divides a data set into multiple smaller data sets, on which the data operations can be applied in parallel, and (ii) the Reduce step aggregates the results into one data set. The goal of this thesis is to enable a dynamic decision making while selecting suitable implementations for the data operations. This mechanism should be able to dynamically decide, which pipeline operators should be processed in a distributed manner, such as using a Map-Reduce implementation, and which operators should be processed by existing technologies, such as in-memory processing by Web Services. This decision is important because Map-Reduce itself can lead to a significant overhead while processing small data sets. Once it is decided that an operation should be processed using Map-Reduce, corresponding Map-Reduce jobs are invoked that process the data. This dynamic decision making can be achieved through WS-Policies. Web Services use policies to declare in a consistent and standardized manner what they are capable of supporting and which constraints and requirements they impose on their potential requestors. By comparing the capabilities of the Web Service with the requirements of the service requestor, it can be decided if the implementation is suitable for executing the data operation.Item Open Access Crawling hardware for OpenTOSCA(2017) Choudhury, PushpamHeterogeneity is the essence of the IoT paradigm. There is heterogeneity in communication and transport protocols, in network infrastructure, and even among the interacting devices themselves. Managing discovery of the different devices in such a paradigm is an extremely complex task. The typical solutions include an abstraction layer, commonly known as the middleware layer, that handles this complexity for the devices, thereby, allowing them to interact with one another. One major limitation of the existing middleware solutions is in their ability to allow for an easily configurable approach required to handle the tremendous scale of heterogeneous components in the IoT. The objective of this thesis is to develop such a highly configurable discovery middleware approach. The proposed approach aims to discover a variety of heterogeneous devices and services depending on a multi-level plugin layer, consisting of independent plugins that interact with each other based on the pipes and filters architectural pattern. To allow for the dynamic configuration of the middleware, a discovery configuration is developed. The output from the middleware includes a list of devices and their capabilities and is accessible via a web interface which can interact with a range of different clients. The proposed approach is validated on a scenario in a real-life environment.Item Open Access Integration of IoT devices via a blockchain-based decentralized application(2017) Ahmad, AfzaalBlockchains are shared, immutable ledgers for recording the history of transactions. They foster a new generation of transactional applications that establish trust, accountability, and transparency. It enables contract partners to secure a deal without involving a trusted third party. Initially, the focus was on financial industry for digital assets trading like Bitcoin, but with the emergence of Smart Contracts, blockchain becomes a complete programmable platform. Many research and commercial organization start diving into blockchain world, bringing new ideas of its application in different sectors like supply chain, Health, and autonomous shopping. This thesis presents an idea to integrate Internet of Things (IoT) devices via a blockchain based decentralize application based on Ethereum. The application consists of front-end application which can be deployed to any web server, and a smart contract which will be deployed on a private blockchain network comprises of Peer-to-Peer (P2P) connected IoT devices acting as full Ethereum node. The application emulates the digital transport ticketing system where the asset is a ticket which can be purchased and paid by the user using ether in their Ethereum account on the blockchain. Once the purchase transaction is mined, it is propagated to all the peers. Ticket can now be accessed locally without requesting any centralized system, which makes the system easily accessible and safe because of the security, data integrity and decentralization of the blockchain-based systems.Item Open Access Dekomposition und Komposition von Microservices(2017) Gutermann, JochenMicroservices haben in den letzten Jahren zunehmend an Popularität gewonnen und werden von einigen großen Unternehmen für hochgradig skalierbare Anwendungen eingesetzt. Beim Entwurf einer Microservice-Architektur stellen sich die Fragen, wie man zu einer geeigneten Service-Aufteilung gelangt und wie man die einzelnen Services zu einer einzigen Anwendung zusammenfügt, sodass die Service-Topologie für die Nutzer transparent bleibt. In einigen Quellen, darunter zahlreiche Blogartikel, werden unterschiedliche Antworten auf diese Fragen präsentiert. Ein systematischer Vergleich konnte jedoch in keiner Quelle gefunden werden. Die vorliegende Arbeit analysiert verschiedene Ansätze zur grundlegenden Aufteilung einer Microservice-Anwendung sowie zur Integration der einzelnen Services, stellt diese anhand verschiedener Kriterien gegenüber und benennt jeweils konkrete Anwendungsfälle dafür. Kriterien zur feingranularen Aufteilung werden aufgezählt und der Einsatz von gemeinsamen Bibliotheken wird diskutiert. Des Weiteren werden die Kompositionsprinzipien Orchestrierung und Choreographie verglichen sowie Möglichkeiten zur Umsetzung von Authentifizierung und Autorisierung bewertet. Im Rahmen einer prototypischen Implementierung werden einige dieser Konzepte angewandt und zuvor gewonnene Erkenntnisse anhand der praktischen Anwendung diskutiert.Item Open Access A platform for collaborative quality assurance of bibliographical references and notes(2017) Müller, TamaraIn scientific work it is common to work in teams, while dealing with an abundance of literature. With the help of a literature management software these can be collected and managed as well as exported in bibliographies. Many online sources offer functionalities to import references into reference management tools. However, the entries are often incomplete or faulty. Hence, this thesis covers a concept for a reference management platform that supports collaborative work and quality assurance of references. The main ideas are to use a group functionality to support collaboration and a rating system for the quality assurance. Additionally, the users can edit reference entries to improve their quality. As part of this thesis, a prototype was implemented which supports both aspects.Item Open Access Concepts for handling heterogeneous data transformation logic and their integration with TraDE middleware(2017) Yussupov, VladimirThe concept of programming-in-the-Large became a substantial part of modern computerbased scientific research with an advent of web services and the concept of orchestration languages. While the notions of workflows and service choreographies help to reduce the complexity by providing means to support the communication between involved participants, the process still remains generally complex. The TraDE Middleware and underlying concepts were introduced in order to provide means for performing the modeled data exchange across choreography participants in a transparent and automated fashion. However, in order to achieve both transparency and automation, the TraDE Middleware must be capable of transforming the data along its path. The data transformation’s transparency can be difficult to achieve due to various factors including the diversity of required execution environments and complicated configuration processes as well as the heterogeneity of data transformation software which results in tedious integration processes often involving the manual wrapping of software. Having a method of handling data transformation applications in a standardized manner can help to simplify the process of modeling and executing scientific service choreographies with the TraDE concepts applied. In this master thesis we analyze various aspects of this problem and conceptualize an extensible framework for handling the data transformation applications. The resulting prototypical implementation of the presented framework provides means to address data transformation applications in a standardized manner.Item Open Access Konzeptioneller Entwurf und Implementierung einer Methode zur automatisierten Verfeinerung von Topologien(2017) Kaul, ArthurIm Bereich moderner Cloud- und serviceorientierter Architekturen, muss in sich ständig ändernden Systemumgebungen, die Systemarchitektur schnell und flexibel an die neuen Anforderungen angepasst und erneut bereitgestellt werden. Daher werden die Systemarchitekturen in diesen Bereichen durch eine Zusammenstellung von abstrakten Komponenten und Services beschrieben, die bei sich ändernden Anforderungen angepasst und in neue ausführbare Systemarchitekturen verfeinert werden können. Eine große Herausforderung bei der Verfeinerung stellt die automatische Zusammenstellung von zueinander kompatiblen ausführbaren Services und Komponenten dar, die alle Anforderungen erfüllen. Um diese Herausforderung zu bewältigen wurde ein Verfeinerungsmodell für die Verfeinerung von abstrakten Systemarchitekturen in ausführbare konkrete Systemarchitekturen entwickelt. Das Verfeinerungsmodell dient als Grundlage für ein semi-automatisiertes Verfeinerungsverfahren von Systemarchitekturen, welche durch Topologiemodelle dargestellt und beschrieben werden. Das Verfeinerungsverfahren wird in einem Architectural Refinement (ArchRef) Tool als Prototyp implementiert und kann für die Modellierung von Topologiemodellen und ihre anschließende automatisierte Verfeinerung verwendet werden.Item Open Access Quality assessment framework for business processes as a service in a heterogeneous cloud environment(2017) Vinayak, RupinderA business process is an activity or set of multiple activities that will fulfill a particular objective of the organization. Business process management (BPM) is a methodological way for the improvement of those processes. Due to increased competition in the market, companies are shifting their business processes online using some sophisticated Business process management (BPM) tools and methods. The focus of this thesis is to design and implementation of an initial testing system for business processes which are published on a heterogeneous Cloud environment. This thesis documents researched the state of the art of business process testing (BPT) which covers some testing techniques and selected the best-suited method for testing business process which is responsible for the quality of the system. Also, it concentrates on the state of the art of testing the Cloud. It focus on different methodologies to test SaaS, PaaS, and IaaS. The main objective for that, is to understand the way how testing Cloud environment works, hence, it will lead to the understanding of testing of business processes as a service. Additionally, it explains the general architecture of the TTCN-3. A design of a test system to test the business process based on TTCN-3 is presented. A case study of CloudSocket has been studied and according to the requirement, we have introduced an initial work for testing BPaaS in a heterogeneous Cloud environment. This initial test system was implemented and validated in the CloudSocket Marketplace.Item Open Access Designing a context-aware discovery service for IoT devices(2017) Khan, Muhammad ArsalanInternet of Things (IoT) is in a continuous expansion phase, from millions of devices to tens of billions in upcoming years, which will have major impacts on infrastructure, business models, and industry standards throughout the entire IT ecosystem. It is expected that several diverse devices to invade by 2020. Depending on different application domains, IoT applications require devices, sensors, middlewares, networks and other enabling technologies to be integrated e.g., the high-level central control of IoT applications can be deployed on the cloud while others are running close to the "edge", forming a unified, scalable and feasible system. One of the important integration aspects in IoT ecosystem is discovering devices and sensors based on a particular context regardless of their heterogeneity. In this thesis, we propose Context-Aware Discovery Service for Internet of Things (CADsIoT) that deals with devices and sensors installed in IoT environments, streamlining the process of registration, management and dynamic discovery of devices based on contextual information. CADsIoT allows device and sensor registration, attaching them with particular context and leverage subscription features to enable dynamic discovery based on the attached context. Additionally, real-time notifications are triggered when new devices are discovered. For the validation of our concept, we discuss the requirements and a descriptive motivation scenario, which is followed by a discussion of the prototypical implementation. The prototype consists of CADsIoT Core, a Representational State Transfer (REST) based middleware and Navigator, an Android mobile application as a client.Item Open Access Securing cloud service archives for function and data shipping in industrial environments(2017) Haider, Muhammad AliCloud Computing paradigm needs a standard for portability, and automated deployment and management of cloud services, to eliminate vendor lock-in and minimization of management efforts respectively. Topology and Orchestration Specification for Cloud Applications (TOSCA) language provides such standard by employing semantics for representation of components and business processes of a cloud application. Advancements in the fields of Cloud Computing and Internet of Things (IoT) has opened new research areas to support 4th industrial revolution (Industry 4.0), which in turn has resulted in the emergence of smart services. One application of smart services is predictive maintenance, which enables the anticipation of future devicesí states by implementing functions, for example, analytics algorithms, and collecting huge amounts of data from sensors. Considering performance demands and runtime constraints, either the data can be shipped to the function site, called data shipping or the functionality is provisioned closely to the data site, called function shipping. However, since this data can contain confidential information, it has to be assured that access to the data is strictly controlled. Although TOSCA already enables defining policies in general, a concrete data security policy approach is missing. Moreover, constituents of TOSCA are packaged in a self-contained and portable archive, called Cloud Service Archive (CSAR), which is also required to be secured and restricted to authorized personals only. Taking the above facts into account, the goal of this thesis is to refine and enhance the TOSCA standard to the field of smart services in production environments through the usage of policies, for example, being effectively able to define the security aspects. In this thesis, various available policy languages with frameworks supporting them are researched, and their applicability for the field of Industry 4.0 is analyzed. An approach is formulated with one language selected, to define policies for TOSCA compliant cloud applications. Furthermore, a prototype is developed to secure the content of CSAR using the proposed approach.