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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Towards Effective and Intelligent Multi-tenancy SaaS

January 2011 (has links)
abstract: Cloud computing has received significant attention recently as it is a new computing infrastructure to enable rapid delivery of computing resources as a utility in a dynamic, scalable, and visualized manner. SaaS (Software-as-a-Service) provide a now paradigm in cloud computing, which goal is to provide an effective and intelligent way to support end users' on-demand requirements to computing resources, including maturity levels of customizable, multi-tenancy and scalability. To meet requirements of on-demand, my thesis discusses several critical research problems and proposed solutions using real application scenarios. Service providers receive multiple requests from customers, how to prioritize those service requests to maximize the business values is one of the most important issues in cloud. An innovative prioritization model is proposed, which uses different types of information, including customer, service, environment and workflow information to optimize the performance of the system. To provide "on-demand" services, an accurate demand prediction and provision become critical for the successful of the cloud computing. An effective demand prediction model is proposed, and applied to a real mortgage application. To support SaaS customization and fulfill the various functional and quality requirements of individual tenants, a unified and innovative multi-layered customization framework is proposed to support and manage the variability of SaaS applications. To support scalable SaaS, a hybrid database design to support SaaS customization with two-layer database partitioning is proposed. To support secure SaaS, O-RBAC, an ontology based RBAC (Role based Access Control) model is used for Multi-Tenancy Architecture in clouds. To support a significant number of tenants, an easy to use SaaS construction framework is proposed. As a summary, this thesis discusses the most important research problems in cloud computing, towards effective and intelligent SaaS. The research in this thesis is critical to the development of cloud computing and provides fundamental solutions to those problems. / Dissertation/Thesis / Ph.D. Computer Science 2011
2

Multi-Tenancy Security in Cloud Computing : Edge Computing and Distributed Cloud

Shokrollahi Yancheshmeh, Ali January 2019 (has links)
With the advent of technology cloud computing has become the next generation of network computing where cloud computing can deliver both software and hardware as on-demand services over the Internet. Cloud computing has enabled small organizations to build web and mobile apps for millions of users by utilizing the concept of “pay-as-you-go” for applications, computing, network and storage resources as on-demand services. These services can be provided to the tenants in different categories: Infrastructure as a Service (IaaS), Platform as a Service (PaaS) and Software as a Service (SaaS). In order to decrease the costs for the cloud users and increase resource utilization, cloud providers try to share the resources between different organizations (tenants) through a shared environment which is called Multi-Tenancy. Even though multi-tenancy‟s benefits are tremendous for both cloud providers and users, security and privacy concerns are the primary obstacles to Multi-Tenancy.Since Multi-Tenancy dramatically depends on resource sharing, many experts have suggested different approaches to secure Multi-Tenancy. One of the solutions is resource allocation and isolation techniques. In most cases, resource allocation techniques consider but are not sufficient for security. OpenStack community uses a method to isolate the resources in a Multi-Tenant environment. Even though this method is based on a smart filtering technique to segregate the resources in Compute nodes (the component that the instances are running on it in OpenStack), this method is not flawless. The problem comes up in the Cinder nodes where the resources are not isolated. This failure can be considered as a security concern for a Multi-Tenant environment in OpenStack. In order to solve this problem, this project explores a method to secure MultiTenancy for both sides in the Compute node and for backend where Block Storage devices for the instances can be isolated as well. / Med tillkomsten av teknik har molnberäkning blivit nästa generation nätverksberäkning där molnberäkning kan leverera både mjukvara och hårdvara som on-demand-tjänster över Internet. Cloud computing har gjort det möjligt för små organisationer att bygga webboch mobilappar för miljontals användare genom att använda begreppet ”pay-as-you-go” för applikationer, datoranläggningar, nätverksoch lagringsresurser som on-demand-tjänster. Dessa tjänster kan tillhandahållas hyresgästerna i olika kategorier: Infrastructure as a Service (IaaS), Platform as a Service (PaaS) och Software as a Service (SaaS). För att minska kostnaderna för molnanvändarna och öka resursanvändningen, försöker molnleverantörer att dela resurserna mellan olika organisationer (hyresgäster) genom en delad miljö som kallas Multi-Tenancy. Men fördelarna med flera hyresgäster är enorma för både molnleverantörer och användare, säkerhetsoch integritetsfrågor är de främsta hindren för Multi-Tenancy. Eftersom Multi-Tenancy dramatiskt beror på resursdelning har många experter föreslagit olika metoder för att säkra Multi-Tenancy. En av lösningarna är resursallokering och isoleringstekniker. I de flesta fall beaktar resursallokeringstekniker men är inte tillräckliga för säkerhet. OpenStack community använder en metod för att isolera resurserna i en Multi-Tenant-miljö.Men denna metod är baserad på en smart filtreringsteknik för att separera resurserna i Compute-noder (komponenten som instansen körs på den i OpenStack), den här metoden är inte felfri. Problemet kommer upp i Cinder-noderna där resurserna inte är isolerade. Detta fel kan betraktas som ett säkerhetsproblem för en Multi-Tenant-miljö i OpenStack. För att lösa detta problem försöker detta projekt säkra Multi-Tenancy för båda sidor i Compute-noden och för backend där Block Storage-enheter för instanserna också kan isoleras.
3

Toward Customizable Multi-tenant SaaS Applications

January 2016 (has links)
abstract: Nowadays, Computing is so pervasive that it has become indeed the 5th utility (after water, electricity, gas, telephony) as Leonard Kleinrock once envisioned. Evolved from utility computing, cloud computing has emerged as a computing infrastructure that enables rapid delivery of computing resources as a utility in a dynamically scalable, virtualized manner. However, the current industrial cloud computing implementations promote segregation among different cloud providers, which leads to user lockdown because of prohibitive migration cost. On the other hand, Service-Orented Computing (SOC) including service-oriented architecture (SOA) and Web Services (WS) promote standardization and openness with its enabling standards and communication protocols. This thesis proposes a Service-Oriented Cloud Computing Architecture by combining the best attributes of the two paradigms to promote an open, interoperable environment for cloud computing development. Mutil-tenancy SaaS applicantions built on top of SOCCA have more flexibility and are not locked down by a certain platform. Tenants residing on a multi-tenant application appear to be the sole owner of the application and not aware of the existence of others. A multi-tenant SaaS application accommodates each tenant’s unique requirements by allowing tenant-level customization. A complex SaaS application that supports hundreds, even thousands of tenants could have hundreds of customization points with each of them providing multiple options, and this could result in a huge number of ways to customize the application. This dissertation also proposes innovative customization approaches, which studies similar tenants’ customization choices and each individual users behaviors, then provides guided semi-automated customization process for the future tenants. A semi-automated customization process could enable tenants to quickly implement the customization that best suits their business needs. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2016
4

Multi-Tenancy and Sub-Tenancy Architecture in Software-As-A-Service (Saas)

January 2017 (has links)
abstract: Multi-tenancy architecture (MTA) is often used in Software-as-a-Service (SaaS) and the central idea is that multiple tenant applications can be developed using compo nents stored in the SaaS infrastructure. Recently, MTA has been extended where a tenant application can have its own sub-tenants as the tenant application acts like a SaaS infrastructure. In other words, MTA is extended to STA (Sub-Tenancy Architecture ). In STA, each tenant application not only need to develop its own functionalities, but also need to prepare an infrastructure to allow its sub-tenants to develop customized applications. This dissertation formulates eight models for STA, and proposes a Variant Point based customization model to help tenants and sub tenants customize tenant and sub-tenant applications. In addition, this dissertation introduces Crowd- sourcing to become the core of STA component development life cycle. To discover fit tenant developers or components to help building and com posing new components, dynamic and static ranking models are proposed. Further, rank computation architecture is presented to deal with the case when the number of tenants and components becomes huge. At last, an experiment is performed to prove rank models and the rank computation architecture work as design. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2017
5

Comparative Analysis of ERP Emerging Technologies

Engebrethson, Ryan 01 June 2012 (has links) (PDF)
This Master's Thesis compares technologies used in the architecture of Enterprise Resource Planning (ERP) Systems to evaluate the benefits and advantages of emerging technologies. The emerging technologies, Cloud Computing, Software as a Service (SaaS) and Multi-Tenancy, could significantly alter the current ERP space and become a primary part of ERP Systems of the future. A survey was sent to industry professionals to obtain feedback on their company's ERP Systems and to collect their comments on these new technologies. The survey results and related analysis show that Emerging Cloud ERP Systems outperform Traditional Legacy ERP Systems in all important characteristics - Accessibility, Business Cost, Implementation Time, Mobility, Scalability, Upgradability, and Usability. Cloud Systems were also found to have a shorter implementation time and a larger proportion of Cloud Systems were on the most recent version of software. Furthermore, industry professionals identified Cloud Computing, SaaS and Mobility as the emerging technologies of the coming decade. This thesis demonstrates that there are significant benefits for companies to use ERP Systems that use the emerging technologies and that the shift to Cloud ERP Systems has begun.
6

Security challenges within Software Defined Networks

Sund, Gabriel, Ahmed, Haroon January 2014 (has links)
A large amount of today's communication occurs within data centers where a large number of virtual servers (running one or more virtual machines) provide service providers with the infrastructure needed for their applications and services. In this thesis, we will look at the next step in the virtualization revolution, the virtualized network. Software-defined networking (SDN) is a relatively new concept that is moving the field towards a more software-based solution to networking. Today when a packet is forwarded through a network of routers, decisions are made at each router as to which router is the next hop destination for the packet. With SDN these decisions are made by a centralized SDN controller that decides upon the best path and instructs the devices along this path as to what action each should perform. Taking SDN to its extreme minimizes the physical network components and increases the number of virtualized components. The reasons behind this trend are several, although the most prominent are simplified processing and network administration, a greater degree of automation, increased flexibility, and shorter provisioning times. This in turn leads to a reduction in operating expenditures and capital expenditures for data center owners, which both drive the further development of this technology. Virtualization has been gaining ground in the last decade. However, the initial introduction of virtualization began in the 1970s with server virtualization offering the ability to create several virtual server instances on one physical server. Today we already have taken small steps towards a virtualized network by virtualization of network equipment such as switches, routers, and firewalls. Common to virtualization is that it is in early stages all of the technologies have encountered trust issues and general concerns related to whether software-based solutions are as rugged and reliable as hardware-based solutions. SDN has also encountered these issues, and discussion of these issues continues among both believers and skeptics. Concerns about trust remain a problem for the growing number of cloud-based services where multitenant deployments may lead to loss of personal integrity and other security risks. As a relatively new technology, SDN is still immature and has a number of vulnerabilities. As with most software-based solutions, the potential for security risks increases. This thesis investigates how denial-of-service (DoS) attacks affect an SDN environment and a single-threaded controller, described by text and via simulations. The results of our investigations concerning trust in a multi-tenancy environment in SDN suggest that standardization and clear service level agreements are necessary to consolidate customers’ confidence. Attracting small groups of customers to participate in user cases in the initial stages of implementation can generate valuable support for a broader implementation of SDN in the underlying infrastructure. With regard to denial-of-service attacks, our conclusion is that hackers can by target the centralized SDN controller, thus negatively affect most of the network infrastructure (because the entire infrastructure directly depends upon a functioning SDN controller). SDN introduces new vulnerabilities, which is natural as SDN is a relatively new technology. Therefore, SDN needs to be thoroughly tested and examined before making a widespread deployment. / Dagens kommunikation sker till stor del via serverhallar där till stor grad virtualiserade servermiljöer förser serviceleverantörer med infrastukturen som krävs för att driva dess applikationer och tjänster. I vårt arbete kommer vi titta på nästa steg i denna virtualiseringsrevolution, den om virtualiserade nätverk. mjukvarudefinierat nätverk (eng. Software-defined network, eller SDN) kallas detta förhållandevis nya begrepp som syftar till mjukvarubaserade nätverk. När ett paket idag transporteras genom ett nätverk tas beslut lokalt vid varje router vilken router som är nästa destination för paketet, skillnaden i ett SDN nätverk är att besluten istället tas utifrån ett fågelperspektiv där den bästa vägen beslutas i en centraliserad mjukvaruprocess med överblick över hela nätverket och inte bara tom nästa router, denna process är även kallad SDN kontroll. Drar man uttrycket SDN till sin spets handlar det om att ersätta befintlig nätverksutrustning med virtualiserade dito. Anledningen till stegen mot denna utveckling är flera, de mest framträdande torde vara; förenklade processer samt nätverksadministration, större grad av automation, ökad flexibilitet och kortare provisionstider. Detta i sin tur leder till en sänkning av löpande kostnader samt anläggningskostnader för serverhallsinnehavare, något som driver på utvecklingen. Virtualisering har sedan början på 2000-talet varit på stark frammarsch, det började med servervirtualisering och förmågan att skapa flertalet virtualiserade servrar på en fysisk server. Idag har vi virtualisering av nätverksutrustning, såsom switchar, routrar och brandväggar. Gemensamt för all denna utveckling är att den har i tidigt stadie stött på förtroendefrågor och överlag problem kopplade till huruvida mjukvarubaserade lösningar är likvärdigt robusta och pålitliga som traditionella hårdvarubaserade lösningar. Detta problem är även något som SDN stött på och det diskuteras idag flitigt bland förespråkare och skeptiker. Dessa förtroendefrågor går på tvären mot det ökande antalet molnbaserade tjänster, typiska tjänster där säkerheten och den personliga integriten är vital. Vidare räknar man med att SDN, liksom annan ny teknik medför vissa barnsjukdomar såsom kryphål i säkerheten. Vi kommer i detta arbete att undersöka hur överbelastningsattacker (eng. Denial-of-Service, eller DoS-attacker) påverkar en SDN miljö och en singel-trådig kontroller, i text och genom simulering. Resultatet av våra undersökningar i ämnet SDN i en multitenans miljö är att standardisering och tydliga servicenivåavtal behövs för att befästa förtroendet bland kunder. Att attrahera kunder för att delta i mindre användningsfall (eng. user cases) i ett inledningsskede är också värdefullt i argumenteringen för en bredare implementering av SDN i underliggande infrastruktur. Vad gäller DoS-attacker kom vi fram till att det som hackare går att manipulera en SDN infrastruktur på ett sätt som inte är möjligt med dagens lösningar. Till exempel riktade attacker mot den centraliserade SDN kontrollen, slår man denna kontroll ur funktion påverkas stora delar av infrastrukturen eftersom de är i ett direkt beroende av en fungerande SDN kontroll. I och med att SDN är en ny teknik så öppnas också upp nya möjligheter för angrepp, med det i åtanke är det viktigt att SDN genomgår rigorösa tester innan större implementation.
7

Abordagem para Qualidade de ServiÃo em Banco de Dados Multi-Inquilinos em Nuvem / Approach for Quality of Service to Multi-Tenant Databases in the Cloud

Leonardo Oliveira Moreira 25 July 2014 (has links)
FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / A computaÃÃo em nuvens à um paradigma bem consolidado de utilizaÃÃo de recursos computacionais, segundo o qual infraestrutura de hardware, software e plataformas para o desenvolvimento de novas aplicaÃÃes sÃo oferecidos como serviÃos disponÃveis remotamente e em escala global. Os usuÃrios de nuvens computacionais abrem mÃo de uma infraestrutura computacional prÃpria para dispÃ-la mediante serviÃos oferecidos por provedores de nuvem, delegando aspectos de Qualidade de ServiÃo (QoS) e assumindo custos proporcionais à quantidade de recursos que utilizam modelo de pagamento baseado no uso. Essas garantias de QoS sÃo definidas entre o provedor do serviÃo e o usuÃrio, e expressas por meio de Acordo de NÃvel de ServiÃo (SLA), o qual consiste de contratos que especificam um nÃvel de qualidade a ser atendido, e penalidades em caso de falha. A maioria das aplicaÃÃes em nuvem à orientada a dados e, por conta disso, Sistemas Gerenciadores de Banco de Dados (SGBDs) sÃo candidatos potenciais para a implantaÃÃo em nuvem. SGBDs em nuvem devem tratar uma grande quantidade de aplicaÃÃes ou inquilinos. Os modelos de multi-inquilinatos sÃo utilizados para consolidar vÃrios inquilinos dentro de um sà SGBD, favorecendo o compartilhamento eficaz de recursos, alÃm de gerenciar uma grande quantidade de inquilinos com padrÃes de carga de trabalho irregulares. Por outro lado, os provedores em nuvem devem reduzir os custos operacionais, garantindo a qualidade. Para muitas aplicaÃÃes, o maior tempo gasto no processamento das requisiÃÃes està relacionado ao tempo de execuÃÃo do SGBD. Portanto, torna-se importante que um modelo de qualidade seja aplicado ao SGBD para seu desempenho. TÃcnicas de provisionamento dinÃmico sÃo voltadas para o tratamento de cargas de trabalho irregulares, para que violaÃÃes de SLA sejam evitadas. Sendo assim, uma estratÃgia para ajustar a nuvem no momento em que se prevà um comportamento que pode violar o SLA de um dado inquilino (banco de dados) deve ser considerada. As tÃcnicas de alocaÃÃo sÃo usadas no intuito de aproveitar os recursos do ambiente em detrimento ao provisionamento. Com base nos sistemas de monitoramento e de modelos de otimizaÃÃo, as tÃcnicas de alocaÃÃo decidem onde serà o melhor local para receber um dado inquilino. Para realizar a transferÃncia do inquilino de forma eficiente, tÃcnicas de Live Migration sÃo adotadas para ter o mÃnimo de interrupÃÃo do serviÃo. Acredita-se que a combinaÃÃo destas trÃs tÃcnicas podem contribuir para o desenvolvimento de um soluÃÃo robusta de QoS para bancos de dados em nuvem, minimizando violaÃÃes de SLA. Ante tais desafios, esta tese apresenta uma abordagem, denominada PMDB, para melhorar QoS em SGBDs multi-inquilinos em nuvem. A abordagem tem como objetivo reduzir o nÃmero de violaÃÃes de SLA e aproveitar os recursos à disposiÃÃo por meio de tÃcnicas que realizam prediÃÃo de carga de trabalho, alocaÃÃo e migraÃÃo de inquilinos quando necessitam de recursos com maior capacidade. Para isso, uma arquitetura foi proposta e um protÃtipo implementado com tais tÃcnicas, alÃm de estratÃgias de monitoramento e QoS voltada para aplicaÃÃes de banco de dados em nuvem. Ademais, alguns experimentos orientados a desempenho foram especificados para mostrar a eficiÃncia da abordagem a fim de alcanÃar o objetivo em foco. / Cloud computing is a well-established paradigm of computing resources usage, whereby hardware infrastructure, software and platforms for the development of new applications are offered as services available remotely and globally. Cloud computing users give up their own infrastructure to dispose of it through the services offered by cloud providers, to which they delegate aspects of Quality of Service (QoS) and assume costs proportional to the amount of resources they use, which is based on a payment model. These QoS guarantees are established between the service provider and the user, and are expressed through Service Level Agreements (SLA). This agreement consists of contracts that specify a level of quality that must be met, and penalties in case of failure. The majority of cloud applications are data-driven, and thus Database Management Systems (DBMSs) are potential candidates for cloud deployment. Cloud DBMS should treat a wide range of applications or tenants. Multi-tenant models have been used to consolidate multiple tenants within a single DBMS, favoring the efficient sharing of resources, and to manage a large number of tenants with irregular workload patterns. On the other hand, cloud providers must be able to reduce operational costs while keeping quality levels as agreed. To many applications, the longer time spent in processing requests is related to the DBMS runtime. Therefore, it becomes important to apply a quality model to obtain DBMS performance. Dynamic provisioning techniques are geared to treat irregular workloads so that SLA violations are avoided. Therefore, it is necessary to adopt a strategy to adjust the cloud at the time a behavior that may violate the SLA of a given tenant (database) is predicted. The allocation techniques are applied in order to utilize the resources of the environment to the dentriment of provisioning. Based on both the monitoring and the optimization models systems, the allocation techniques will decide the best place to assign a given tenant to. In order to efficiently perform the transfer of the tenant, minimal service interruption, Live Migration techniques are adopted. It is believed that the combination of these three techniques may contribute to the development of a robust QoS solution to cloud databases which minimizes SLA violations. Faced with these challenges, this thesis proposes an approach, called PMDB, to improve DBMS QoS in multi-tenant cloud. The approach aims to reduce the number of SLA violations and take advantage the resources that are available using techniques that perform workload prediction, allocation and migration of tenants when greater capacity resources are needed. An architecture was then proposed and a prototype implementing such techniques was developed, besides monitoring strategies and QoS oriented database applications in the cloud. Some performance oriented experiments were then specified to show the effectiveness of our approach.
8

Multi-Tenant Apache Kafka for Hops : Kafka Topic-Based Multi-Tenancy and ACL- Based Authorization for Hops

Dessalegn Muruts, Misganu January 2016 (has links)
Apache Kafka is a distributed, high throughput and fault-tolerant publish/subscribe messaging system in the Hadoop ecosystem. It is used as a distributed data streaming and processing platform. Kafka topics are the units of message feeds in the Kafka cluster. Kafka producer publishes messages into these topics and a Kafka consumer subscribes to topics to pull those messages. With the increased usage of Kafka in the data infrastructure of many companies, there are many Kafka clients that publish and consume messages to/from the Kafka topics. In fact, these client operations can be malicious. To mitigate this risk, clients must authenticate themselves and their operation must be authorized before they can access to a given topic. Nowadays, Kafka ships with a pluggable Authorizer interface to implement access control list (ACL) based authorization for client operation. Kafka users can implement the interface differently to satisfy their security requirements. SimpleACLAuthorizer is the out-of-box implementation of the interface and uses a Zookeeper for ACLs storage.HopsWorks, based on Hops a next generation Hadoop distribution, provides support for project-based multi-tenancy, where projects are fully isolated at the level of the Hadoop Filesystem and YARN. In this project, we added Kafka topicbased multi-tenancy in Hops projects. Kafka topic is created from inside Hops project and persisted both at the Zookeeper and the NDBCluster. Persisting a topic into a database enabled us for topic sharing across projects. ACLs are added to Kafka topics and are persisted only into the database. Client access to Kafka topics is authorized based on these ACLs. ACLs are added, updated, listed and/or removed from the HopsWorks WebUI. HopsACLAuthorizer, a Hops implementation of the Authorizer interface, authorizes Kafka client operations using the ACLs in the database. The Apache Avro schema registry for topics enabled the producer and consumer to better integrate by transferring a preestablished message format. The result of this project is the first Hadoop distribution that supports Kafka multi-tenancy.
9

Platforma za transformaciju softverskih rešenja pametnih elektroenergetskih mreža na cloud bazirani višeorganizacijski SaaS / A Platform for Smart Grid Software Solution Migration to Cloud Based SaaS

Dalčeković Nikola 13 September 2019 (has links)
<p>Sve češćom upotrebom cloud okruženja dolazi do potrebe da se postojeća softverska rešenja migriraju. Metodologija za migraciju na cloud postoji više, gde se u finalnim fazama planiraju modifikacije nad arhitekturom softvera tako da se iskoriste prednosti cloud sistema. Za ekonomsku efikasnost usled uštede resursa je neophodna višeorganizacijska osobina. Svrha ovog istraživanja je da pojasni višeorganizacijsko svojstvo i da predloži rešenje za migraciju postojećih softvera na višeorganizacijski SaaS ali sa što manje neophodnih modifikacija ciljnog softvera. S toga je predloženo rešenje platforma koja omogućuje lakšu migraciju. Nakon faze istraživanja i sagledavanja domena pametnih elektroenergetskih mreža, kreiran je prototip predloženog rešenja kao i niz eksperimenata u skladu sa definisanim naučnim pitanjima. Eksperimenti su izvršeni u privatnom cloud okruženju. Hipoteze su adresirane kroz viziju primene rešenja na NDMS (Napredni distributivni menadžment sistem) u slučaju šest organizacija, a doneti su sledeći zaključci: višeorganizacijskim modelom se ostvaruju uštede u resursima od 32%, za tri reda veličine veća visoka dostupnost, ali uz usporenja do 20 milisekundi po svakom servisnom zahtevu. Takođe, aplikativni model učesnika modernih PaaS usluga nije primeren gde je sinhronizam zahtevan, niti u slučajevima gde se očekuju odgovori nad skupom učesnika u realnom vremenu. Istraživanje ukazuje na mogućnost primene višeorganizacijskog modela čak i u slučaju kompleksnih rešenja kakva se sreću u domenu pametnih elektroenergetskih mreža, a akademskom validacijom potvrđuju način implementacije važnog finalnog koraka u procesu migracije softvera na cloud bazirani SaaS.</p> / <p>Progressive cloud adoption requires migration of existing software solutions. Today, many cloud adoption methodologies exist. Usually, the final phase in cloud adoption include software architecture modifications to make the most of the benefits of cloud computing, like multi-tenancy which enables economic efficiency. The aim of this research is to explain the multi-tenancy and to provide a solution for migration of existing software to multi-tenant SaaS while modifying the target software as little as possible. Therefore, the research proposes a platform that enables easier cloud adoption. After the research phase focused on a smart grid domain, the prototype was created with experiments targeting formulated research questions. The experiments were conducted in a private cloud environment. Research hypotheses were analyzed using hypothetical multi-tenant ADMS (Advanced Distribution Management System) in case of six tenants, with the following conclusions: multi-tenancy saves 32% of resources, it provides three orders of magnitude higher availability, but affects performances by introducing a delay of up to 20 milliseconds per service request. Also, reliable actors programing model used in modern PaaS services is not suitable in use cases with needs for synchronous behavior, nor in in use cases where querying a set of actors is needed in real time. The research demonstrates feasibility of applying multi-tenancy even in cases of complex software solutions like the ones in the smart grid domain. The proposed solution is academically validated and it can be used as a final important step in migration of existing software to cloud based multi-tenant SaaS.</p>
10

Project based multi-tenant managed RStudio on Kubernetes for Hopsworks / Projektbaserad hanterad RStudio för flera användare på Kubernetes i Hopsworks

Chikafa, Gibson January 2021 (has links)
In order to fully benefit from cloud computing, services are designed following the “multi-tenant” architectural model which is aimed at maximizing resource sharing among users. However, multi-tenancy introduces challenges of security, performance isolation, scaling and customization. RStudio server is an open source Integrated Development Environment (IDE) accessible over a web browser for R programming language. The purpose of this thesis is to develop an open source multi-user distributed system on Hopsworks, a data intensive and AI platform, following the multi-tenant model, that provides RStudio as Software as a Service (SaaS). Our goal is to promote collaboration among users when using RStudio and the learning and teaching of R by enabling users easily have access to same computational environments and resources while eliminating installation and maintenance tasks. Hopsworks introduces project-based multi-tenancy where users within a project share project resources (e.g datasets, programs and services) for collaboration which introduces one more challenge of sharing project resources in RStudio server instances. To achieve our purpose and goal we therefore needed to solve the following problems: performance isolation, security, project resources sharing, scaling and customization. Our proposed model is on demand single user RStudio server instances per project. Our system is built around Docker and Kubernetes to solve the problems of performance isolation, security and scaling. We introduce HopsFS-mount, that allows securely mounting HopsFS via FUSE to solve the project resources (datasets and programs) sharing problem. We integrate our system with Apache Spark which can scale and handle Big Data processing workloads. Also we provide a UI where users can provide custom configuration and have full control of their own RStudio server instances. Our system was tested on a GCP cluster with four worker nodes each with 30GB of RAM allocated to them. The tests on this cluster showed that 44 RStudio servers, each with 2GB of RAM, can be run concurrently. Our system can scale out to potentially support hundreds of concurrently running RStudio servers by adding more resources (CPUs and RAM) to the cluster or system. / För att dra full nytta av molntjänster är vissa applikationer designade för multitenans som syftar till att maximera resursdelning mellan användare. Dock introducerar multitenans utmaningar i hänsyn till resursdelning, säkerhet, prestandaisolering, anpassning och skalning. RStudio-server är en öppen källkod Integrerad utvecklingsmiljö (IDE) tillgänglig över en webbläsare för programmeringsspråket R. Syftet med denna avhandling är att utveckla ett distribuerat system med öppen källkod för flera användare på Hopsworks, en data krävande AI-plattform, efter multitenans-modellen, som tillhandahåller RStudio som Software as a Service (SaaS). Vårt mål är att främja samarbete mellan användare vid användning av RStudio, inlärning och undervisning av R genom att göra det enkelt för användare att ha tillgång till samma beräknings miljöer och resurser samtidigt som installation och underhållsarbete elimineras. Hopsworks introducerar projektbaserad multitenans där användare inom ett projekt delar projektresurser (t.ex. datamängder, program och tjänster) för samarbete som introducerar ytterligare en utmaning att dela projektresurser i RStudio server instanser. För att uppnå vårt syfte och mål behövde vi därför lösa följande problem: prestandaisolering, säkerhet, projekt resursdelning, skalning och anpassning. Vår föreslagna modell är på bergäran en-användares RStudio-serverinstanser per projekt. Vårt system är byggt kring Docker och Kubernetes för att lösa problemen med prestanda isolering, säkerhet och skalning. Vi introducerar HopsFS-mount, som gör det möjligt att säkert montera HopsFS via FUSE för att lösa resurs (datamängder och program) delning problemet. Vi integrerar vårt system med Apache Spark som kan skala och hantera Big Data bearbetning belastningar. Vi tillhandahåller också ett användargränssnitt där användare kan tillhandahålla anpassad konfiguration och ha full kontroll över sina egna RStudio-serverinstanser. Vårt system testades på ett GCP-kluster med fyra arbets noder, varje node hade 30 GB RAM. Testerna på detta kluster visade att 44 RStudio-servrar, var och en med 2 GB RAM, kan köras samtidigt. Vårt system kan även skala ut för att potentiellt stödja hundratals RStudio-servrar som samtidigt körs genom att lägga till fler resurser (CPU:er och RAM) i klustret eller systemet.

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