Abdallah Ali Zainelabden Abdallah Ibrahim

Service Level Agreement Assurance between Cloud Services Providers and Cloud Customers

Cloud services providers deliver cloud services to cloud customers on pay-per-use model while the quality of the provided services are defined using service level agreements also known as SLAs. Unfortunately, there is no standard mechanism which exists to verify and assure that delivered services satisfy the signed SLA agreement in an automatic way. There is no guarantee in terms of quality. Those applications have many performance metrics. In this doctoral thesis, we propose a framework for SLA assurance, which can be used by both cloud providers and cloud users. Inside the proposed framework, we will define the performance metrics for the different applications. We will assess the applications performance in different testing environment to assure good services quality as mentioned in SLA. The proposed framework will be evaluated through simulations and using testbed experiments. After testing the applications performance by measuring the performance metrics, we will review the time correlations between those metrics.

Virtual Desktop Infrastructures: Architecture, survey and green aspects proof of concept

Virtual Desktop Infrastructure (VDI) is a new generation of cloud service in which users operating systems execute in a cloud data center. Users can access their desktops and applications by using thin client devices. This thin client is consisting of only a screen attached with low power CPU. This new paradigm of delivering remote desktop provides benefits in terms of flexibility, cost reduction, data security and energy saving which are the green benefits from using VDI. VDI becomes an important technology in green computing and energy saving. In this paper, we present and review the green benefits for using VDI in large and small organizations. The usefulness and energy-saving features of VDI are also illustrated by some experiments.

PRESENCE: Monitoring and Modelling the Performance Metrics of Mobile Cloud SaaS Web Services

Service Level Agreements (SLAs) are defining the quality of the services delivered from the Cloud Services Providers (CSPs) to the cloud customers. The services are delivered on a pay-per-use model. The quality of the provided services is not guaranteed by the SLA because it is just a contract. The developments around mobile cloud computing and the advent of edge computing technologies are contributing to the diffusion of the cloud services and the multiplication of offers. Although the cloud services market is growing for the coming years, unfortunately, there is no standard mechanism which exists to verify and assure that delivered services satisfy the signed SLA agreement in an automatic way. The accurate monitoring and modelling of the provided Quality of Service (QoS) is also missing. In this context, we aim at offering an automatic framework named PRESE NCE, to evaluate the QoS and SLA compliance of Web Services (WSs) offered across several CSPs. Yet unlike other approaches, PRESE NCE aims at quantifying in a fair and by stealth way the performance and scalability of the delivered WS. This article focuses on the first experimental results obtained on the accurate modelisation of each individual performance metrics. Indeed, 19 generated models are provided, out of which 78.9% accurately represent the WS performance metrics for two representative SaaS web services used for the validation of the PRESE NCE approach. This opens novel perspectives for assessing the SLA compliance of Cloud providers using the PRESE NCE framework.

Law as a service (LaaS): Enabling legal protection over a blockchain network

Breaches in online contracts (Service Level Agreements, SLAs) are usually compensated by gift vouchers at present, however as the online contracts emerge towards smart contracts, the breaches could potentially lead to court injunctions over blockchains. This research proposes Probability based Factor Model (PFM) that can be implemented over the blockchain to automatically identify breaches that can cause substantial damage and have high probability for recurrence. PFM can also issue court injunctions for the breaches. The underlying concept in PFM is built upon the notion of factor analysis and stochastic modeling from the discipline of Data Science. High performance computing (HPC) cluster at University of Luxembourg (HPC @ Uni.lu) and docker (a software container platform) were used to emulate contractual environment of three service providers: Redis, MongoDB, and Memcached Servers. The results showed that court injunction(s) was issued only for Redis and MongoDB Servers. Technically, this difference could be attributed to the fact that Memcached is simply used for caching and therefore, it is less prone to breach of contract. Whereas, Redis and MongoDB as databases and message brokers are performing more complex operations and are more likely to cause a breach. This research will benefit enterprises that view breach of contract as a limiting factor for implementation of smart contract in cyber-physical system or internet of things.

On Service Level Agreement Assurance in Cloud Computing Data Centers

Cloud computing uses internet data centers to host applications and data storage. Cloud computing resources and services are offered to customers on pay-per-use model while the quality of the offered resources and services are defined using service level agreements also known as SLAs. Unfortunately, there is no standard mechanism to verify and assure that services delivered by the cloud provider satisfy the SLA agreement in an automatic way. To fill this gap we propose a framework for SLA assurance, which can be used by both cloud providers and cloud users. The proposed framework assesses performance of cloud applications with and without introducing system and component failures and then helps to resolve or mitigate failures to assure the required quality of cloud applications. The evaluation results obtained through simulations and using testbed experiments demonstrate good agreement with the design objectives.