CLOSER 2013 Abstracts

Area 1 - Cloud Computing Fundamentals
Full Papers Short Papers
Area 2 - Services Science Foundation for Cloud Computing
Full Papers Short Papers
Area 3 - Cloud Computing Platforms and Applications
Full Papers Short Papers
Area 4 - Cloud Computing Enabling Technology
Full Papers Short Papers

Area 1 - Cloud Computing Fundamentals

Full Papers
Paper Nr: 10
Title:

To Frag or to Be Fragged - An Empirical Assessment of Latency in Cloud Gaming
Authors:

Ulrich Lampe, Qiong Wu, Ronny Hans, André Miede and Ralf Steinmetz
Abstract: With the emergence of cloud computing, diverse types of Information Technology services are increasingly provisioned through large data centers via the Internet. A relatively novel service category is cloud gaming, where video games are executed in the cloud and delivered to a client as audio/video stream. While cloud gaming substantially reduces the demand of computational power on the client side, thus enabling the use of thin clients, it may also affect the Quality of Service through the introduction of network latencies. In this work, we quantitatively examine this effect, using a self-developed measurement tool and a set of actual cloud gaming providers. For the two providers and three games in our experiment, we find absolute increases in latency between approximately 40 ms and 150 ms, or between 85% and 800% in relative terms.
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Paper Nr: 17
Title:

Hybrid Cloud Intermediaries - Facilitating Cloud Sourcing for Small and Medium-sized Enterprises
Authors:

Till Haselmann and Gottfried Vossen
Abstract: Whilst “the cloud” is pervasively advertised as a silver bullet for many IT-related challenges of small and medium-sized enterprises (SMEs) because it can potentially lead to many attractive benefits, many SMEs refrain from using cloud services because of high upfront costs for building the appropriate knowledge in the enterprise, for searching and screening of possible cloud service providers (CSPs), and for mastering the intricate legal issues related to outsourcing sensitive data. In this paper, we present hybrid cloud intermediaries, a concept that can address many of the prevailing issues. We describe the concept in detail and show conceivable variants, including a comprehensive cross-perspective consolidated model of cloud intermediary value-creation. Subsequently, we analyze the benefits of such a hybrid cloud intermediary for SMEs and suggest suitable governance structures based on the cooperative paradigm. The resulting entity is concisely called a coop cloud.
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Paper Nr: 48
Title:

Hypervisor Integrity Measurement Assistant
Authors:

Lars Rasmusson and Mazdak Rajabi Nasab
Abstract: An attacker who has gained access to a computer may want to run arbitrary programs of his choice, and upload or modify configuration files, etc. We can severely restrict the power of the attacker by having a white-list of approved file checksums and a mechanism that prevents the kernel from loading any file with a bad checksum. The check may be placed in the kernel, but that requires a kernel that is prepared for it. The check may also be placed in a hypervisor which intercepts the kernel and prevents the kernel from loading a bad file. Moving the integrity check out from the VM kernel makes it harder for the intruder to bypass the check. We describe the implementation of two systems and give performance results. In the first implementation the checksumming and decision is performed by the hypervisor instead of by the kernel. In the second implementation the kernel computes the checksum and only the final integrity decision is made by the hypervisor. We conclude that it is technically possible to put file integrity control into the hypervisor, both for kernels without and with pre-compiled support for integrity measurement.
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Paper Nr: 77
Title:

Migrating Application Data to the Cloud using Cloud Data Patterns
Authors:

Steve Strauch, Vasilios Andrikopoulos, Thomas Bachmann and Frank Leymann
Abstract: Taking advantage of the capabilities offered by Cloud computing requires either an application to be built specifically for it, or for existing applications to be migrated to it. In this work we focus on the latter case, and in particular on migrating the application data. Migrating data to the Cloud creates a series of technical, architectural and legal challenges that the State of the Art attempts to address. We organize such efforts into a set of migration scenarios and connect them with a list of reusable solutions for the application data migration in the form of patterns. From there we define an application data migration methodology and we demonstrate how it can be used in practice.
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Paper Nr: 79
Title:

Monitoring of SCA-based Applications in the Cloud
Authors:

Mohamed Mohamed, Djamel Belaïd and Samir Tata
Abstract: Cloud computing is a recent paradigm in information technology enabling an economic model for virtual resources provisioning. Monitoring remains an important task to efficiently manage the Cloud, but it is still a challenge to find a monitoring solution that reconciles the scalability, the memory consumption, and the efficiency. In this paper, we propose an extension for Service Component Architecture to allow the description of monitoring needs, and a framework that adds monitoring facilities to components and encapsulates them in a scalable micro-container that could be deployed in the cloud. Unlike the existing initiatives in the state of the art, our SCA-extension allows the architect to describe monitoring needs between components and our framework allows the transformation from the extended SCA description to a standard SCA that could be handled by any SCA runtime. This makes the task of developers and architects easier letting them focusing on the business of their components instead of the non functional property of monitoring. Moreover, our framework uses a scalable micro-container for components’ deployment in the Cloud to be in line with the scalability of this environment. The evaluation that we performed proves the efficiency and the flexibility of our approach of monitoring applications in the Cloud.
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Paper Nr: 88
Title:

Comparison of Cloud Middleware Protocols and Subscription Network Topologies using CReST, the Cloud Research Simulation Toolkit - The Three Truths of Cloud Computing are: Hardware Fails, Software has Bugs, and People Make Mistakes
Authors:

John Cartlidge and Dave Cliff
Abstract: We introduce the Cloud Research Simulation Toolkit (CReST), a new cloud computing simulation tool designed to enable cloud providers to research and test their systems before release. We compare CReST with other known cloud simulation tools and demonstrate the utility of CReST by evaluating different distributed middleware protocols and associated subscription network topologies for robustness and reliability. Our results extend previous work and demonstrate that the published literature contains inaccuracies. CReST has been released as open-source under a Creative Commons license on SourceForge, with the intention that it can be used and extended by the cloud computing research community.
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Short Papers
Paper Nr: 16
Title:

SLA Management in Clouds
Authors:

Nikoletta Mavrogeorgi, Spyridon Gogouvitis, Athanasios Voulodimos, Dimosthenis Kiriazis, Theodora Varvarigou and Elliot K. Kolodner
Abstract: The need for online storage and backup of data constantly increases. Enterprises from different domains, such as media and telco operators, would like to be able to store large amounts of data which can then be made available from different geographic locations. The Cloud paradigm allows for the illusion of unlimited online storage space, hiding the complexity of managing a large infrastructure from the end users. While Storage Cloud solutions, such as Amazon S3, have already met with success, more fine-grained guarantees on the provided QoS need to be offered for their larger uptake. In this paper, we address the problem of managing SLAs in Storage Clouds by taking advantage of the content terms that pertain to the stored objects thus supporting more efficient capabilities, such as quicker search and retrieval operations. A system that better captures the content of the signed SLAs is very useful, as the benefits in terms of reducing the management overhead while offering better services are potentially significant.
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Paper Nr: 21
Title:

Taas – Ticketing as a Service
Authors:

João C. Ferreira, Porfírio P. Filipe, Carina Gomes, Gonçalo Cunha and João Silva
Abstract: The goal of this research work is to introduce the concept of a lower cost and flexible system for transport ticketing purposes implemented on a cloud platform. We propose therefore the evolution of the traditional architecture of ticketing system for a cloud based architecture in which the core processes of ticketing are offered through a Software-as-a-Service (SaaS) business model, which can be subscribed by operators that pay-per-use. Ticketing device (e.g. gates, validators, ticket vending machines) are integrated in the cloud environment. This approach is achieved by moving business logic from terminals to the cloud. Each terminal is registered to be managed by each own operator, configuring a multi-tenant implementation which is vendor hardware independent, allowing to address elasticity and interoperability issues. The elasticity of the cloud will support the expansion/implosion of small (transport) operators business around electronic ticketing. In the near future, this ticketing solution will promote collaboration between transport operators.
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Paper Nr: 50
Title:

Energy Sustainability in Cooperating Clouds
Authors:

Antonio Celesti, Antonio Puliafito, Francesco Tusa and Massimo Villari
Abstract: Nowadays, cloud federation is paving the way toward new business scenarios in which it is possible to enforce more flexible energy management strategies than in the past. Considering independent cloud providers, each one is exclusively bounded to the specific energy supplier powering its datacenter. The situation radically change if we consider a federation of cloud providers each one powered by both a conventional energy supplier and a renewable energy generator. In such a context the opportune relocation of computational workload among providers can lead to a global energy sustainability policy for the whole federation. In this work, we investigate the advantages, constrains, and issues for the achievement of such a sustainable environment.
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Paper Nr: 65
Title:

A Multi-Agent based Architecture for Cloud Infrastructure Auto-adaptation
Authors:

Hanen Chihi, Walid Chainbi and Khaled Ghedira
Abstract: Cloud computing including hardware, software, communication and networks are growing towards an ever increasing scale and heterogeneity, becoming overly complex. To manage such growing complexity, autonomic computing focuses on self-adaptable computing systems to the maximum extent possible without human intervention or guidance. In this paper, we design a multi-agent-based architecture for Cloud infrastructure auto-adaptation. This model is based on distributed multi-agent systems which collaborate to enrich the Cloud with self-* capabilities. The proposed model represents an effective method to reduce servers’ power consumption while achieving the required performance and providing trusted Cloud.
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Paper Nr: 92
Title:

Improve Resource-sharing through Functionality-preserving Merge of Cloud Application Topologies
Authors:

Tobias Binz, Uwe Breitenbücher, Oliver Kopp, Frank Leymann and Andreas Weiß
Abstract: Resource sharing is an important aspect how cost savings in cloud computing are realized. This is especially important in multi-tenancy settings, where different tenants share the same resource. This paper presents an approach to merge two application topologies into one, while on the one hand preserving the functionality of both applications and on the other hand enabling sharing of similar components. Previous work has not addressed this due to the lack of ways to describe topologies of composite applications in a decomposed, formal, and machine-readable way. New standardization initiatives, such as TOSCA, provide a way to describe application topologies, which are also portable and manageable. We propose an approach, realization, and architecture enabling a functionality-preserving merge of application topologies. To validate our approach we prototypically implemented and applied it to merge a set of test cases. All in all, the functional-preserving merge is a method to support the optimization and migration of existing applications to the cloud, because it increases resource sharing in the processed application topologies.
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Paper Nr: 93
Title:

S-Discovery: A Behavioral and Quality-based Service Discovery on the Cloud
Authors:

Ahmed Gater, Fernando Lemos, Daniela Grigori and Mokrane Bouzeghoub
Abstract: Cloud computing recently emerged as a paradigm providing computer power and storage as a utility that is consumed on demand (following the footsteps of other utilities, like electricity). Recently, a new service delivery mode emerged: Business Process as a Service (BPaaS). As a consequence, process models repositories will be developed allowing this new type of services to be published by process providers and discovered by enterprises wanting to outsource some of, or parts of, their processes. In this paper we present the S-Discovery framework allowing to find in such repositories processes that could satisfy user functional and no-functional requirements.
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Paper Nr: 115
Title:

The Case for Cloud Service Trustmarks and Assurance-as-a-Service
Authors:

Theo Lynn, Philip Healy, Richard McClatchey, John Morrison, Claus Pahl and Brian Lee
Abstract: Cloud computing represents a significant economic opportunity for Europe. However, this growth is threatened by adoption barriers largely related to trust. This position paper examines trust and confidence issues in cloud computing and advances a case for addressing them through the implementation of a novel trustmark scheme for cloud service providers. The proposed trustmark would be both active and dynamic featuring multi-modal information about the performance of the underlying cloud service. The trustmarks would be informed by live performance data from the cloud service provider, or ideally an independent third-party accountability and assurance service that would communicate up-to-date information relating to service performance and dependability. By combining assurance measures with a remediation scheme, cloud service providers could both signal dependability to customers and the wider marketplace and provide customers, auditors and regulators with a mechanism for determining accountability in the event of failure or non-compliance. As a result, the trustmarks would convey to consumers of cloud services and other stakeholders that strong assurance and accountability measures are in place for the service in question and thereby address trust and confidence issues in cloud computing.
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Paper Nr: 34
Title:

Cloud Migration Process - Case Study on Business Migration Process to the Cloud
Authors:

Lukasz Ostrowski, Markus Helfert and Huanhuan Xhiong
Abstract: Cloud computing has become a trend in the Information Systems (IS) field and provides an interesting prospect for the Information Technology (IT) industry. Main reasons why business are moving into the cloud is due to the opportunity for costs reduction, flexibility, and high automation. However, moving all business data into the cloud raises some security concerns. Hence, our work is to determine a business process for migration businesses to the cloud that adds transparency and clarify ambiguities of this move to small-medium business holders. In this paper we describe our approach to design a migration process for small-medium enterprises, therefore following process-oriented reference model in design science research. We present the migration process and underline various migration options and proven methods to increase its adaptation to business.
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Paper Nr: 40
Title:

Interoperability Standards for Cloud Architecture
Authors:

Claus Pahl, Li Zhang and Frank Fowley
Abstract: Enabling cloud infrastructures to evolve into a transparent platform raises interoperability issues. Interoperability requires standard data models and communication technologies compatible with the existing Internet infrastructure. To reduce vendor lock-in situations, cloud computing must implement common strategies regarding standards, interoperability and portability. Open standards are of critical importance and need to be embedded into interoperability solutions. Interoperability is determined at the data level as well as the service level. Relevant modelling standards and integration solutions shall be analysed in the context of clouds.
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Paper Nr: 54
Title:

Towards a Standards-based Cloud Service Manager
Authors:

Amine Ghrab, Sabri Skhiri, Hervé Koener and Guy Leduc
Abstract: Migrating services to the cloud brings all the benefits of elasticity, scalability and cost-cutting. However, migrating services among different cloud infrastructures or outside the cloud is not an obvious task. In addition, distributing services among multiple cloud providers, or on a hybrid installation requires a custom implementation effort that must be repeated at each infrastructure change. This situation raises the lock-in problem and discourages cloud adoption. Cloud computing open standards were designed to face this situation and to bring interoperability and portability to cloud environments. However, they target isolated resources, and do not take into account the notion of complete services. In this paper, we introduce an extension to OCCI in order to support complete service definition and management automation. We support this proposal with an open-source framework for service management through compliant cloud infrastructures.
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Paper Nr: 69
Title:

Building a Knowledge Base for Guiding Users through the Cloud Life Cycle
Authors:

Claudio Giovanoli and Stella Gatziu Grivas
Abstract: Cloud Computing is still a hype to provide IT services as customers demand. Especially small and medium size businesses can benefit of this new trend because of the flexibility Cloud Computing provides for the consumption of its services. Nevertheless the step into the cloud must be carefully prepared and setup to ensure a successful usage and an appropriate return on investment. Currently the lack of experience with cloud projects and the uncertainty of its predestined application areas are detaining companies to use cloud computing services. No best practices, rules and use cases are in place yet to help to convince potential users to go their way to the cloud. With the CLiCk project the authors therefore propose a personalized web-based platform for Small and Medium Enterprises to support them over an entire Cloud Life Cycle.
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Paper Nr: 97
Title:

Choreography Conformace Checking based on Process Algebras
Authors:

Manuel I. Capel
Abstract: Business Process Modelling (BPM) is a conceptual activity for representing processes of an enterprise. A business process can be understood as a set of related, structured, interacting activities driven by a choreography that is capable of giving complex services to customers. The ways in which a choreography can be specified in order to check if the behaviour described is conformant with the peer--based interactions of a distributed target system, and thus to prove safety properties, should be correctly defined by identifying the appropriate processes. Hence, choreographies becomes now of great use to analyze and improve any modern company's business.
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Paper Nr: 101
Title:

A Causal Tracking Monitoring Approach for Business Transaction Management
Authors:

Yehia Taher, Willem-Jan van den Heuvel, Salima Benbernou and Rafiqul Haque
Abstract: Business transaction are automated, agreed-upon, long running propositions between multiple trading partners, that are specified over Service Level Agreement as constraints that need to be compliant. However, these constraints could be violated at any time due to various unexpected events. In this paper we propose a Business Transaction Management (BTM) system that amalgamates existing service composition and monitoring techniques (e.g.,BPEL) with complex event processing (CEP) technology. The proposed system is a first important step toward effective support of end-to-end processes that can monitor their own performance by sensing and interacting with the physical word, and repair, upgrade, or replace themselves proactively.
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Paper Nr: 117
Title:

Security Quantification of Complex Attacks in Infrastructure as a Service Cloud Computing
Authors:

Doudou Fall, Takeshi Okada, Noppawat Chaisamran, Youki Kadobayoshi and Suguru Yamaguchi
Abstract: It is a truism to single out the inherent security issues of cloud computing as the main hurdle to its adoption. Particularly, infrastructure clouds are composed of multiple components and applications where vulnerabilities are regularly discovered. We propose a probabilistic security quantification method, which allows quantifying the security level of a given Infrastructure as a Service cloud environment. We translate the vulnerable IaaS environment into a vulnerability tree that we built basing on fault tree analysis, which is a well established modeling tool. The analysis of the vulnerability tree leads us to the security quantification formula.
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Paper Nr: 118
Title:

Decision Support for Application Migration to the Cloud - Challenges and Vision
Authors:

Vasilios Andrikopoulos, Steve Strauch and Frank Leymann
Abstract: The success of Cloud computing has encouraged many application developers to consider migrating their applications to the Cloud. Given the early market dominance of the IaaS service model, many existing works focus on selecting the best service provider for a set of criteria related to the virtualization and hosting of the application. In this work, we aim to progress the State of the Art by formulating a vision of a decision support system that incorporates multiple dimensions and different analysis tasks in feedback relationships with each other. The research challenges that need to be addressed towards this direction are identified and related to the different aspects of migration of applications to the various Cloud service models.
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Paper Nr: 120
Title:

PaaS Federation Analysis for Seamless Creation and Migration of Cloud Applications
Authors:

Daniel A. Rodriguez-Silva, Lilian Adkinson-Orellana, Dolores M. Nuñez-Taboada and F. Javier González-Castaño
Abstract: A major concern regarding the development of cloud applications is provider lock-in. There are no standard solutions to this problem with the exception of some attempts of achieving interoperability at the infrastructure level. This paper presents an analysis focused on the federation at PaaS level. Furthermore, the proposed schemes are intended to simplify the design of cloud applications by means of a declarative programming based on a set of modules available in all supported platforms. Hence, designed applications can migrate between platforms easily, enabling the creation of new fault-tolerant architectures.
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Area 2 - Services Science Foundation for Cloud Computing

Full Papers
Paper Nr: 38
Title:

Multi-Cloud Governance Service based on Model Driven Policy Generation
Authors:

Juan Li, Wendpanga Francis Ouedraogo and Frédérique Biennier
Abstract: Cloud computing is an innovative and promising paradigm that is leading to remarkable changes in the way we manage our business. Cloud computing can provide scalable IT infrastructure, QoS-assured services and customizable computing environment. Such scalable and agile environment increases the call for agile and dynamic deployment and governance environments over multi-cloud infrastructure. Unfortunately, by now, governance and Non Functional Properties (such as security, QoS…) are managed in a static way, limiting the global benefits of deploying service-based information system over multi-cloud environments. To overcome this limit, we propose a contextualised policy generation process to allow both an agile management NFP in a multi-cloud context and a secured deployment of the service-based information system. Thanks to the generation of these NFP policies, NFP management functions can be orchestrated at runtime so that the exact execution context can be taken into account.
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Paper Nr: 57
Title:

A Versatile and Scalable Everything-as-a-Service Registry and Discovery
Authors:

Josef Spillner and Alexander Schill
Abstract: Networked humans and autonomous systems rely increasingly on service-oriented architectures. Conventional systems often focus on digitally delivered web services or on business services with varying degrees of formalisation. According to service integration principles, the service registry as the pivotal point between providers and consumers determines the types of services which can be found and delivered. With the growing importance of cloud computing topics in research and industry, more generic service models, description languages and registry architectures are proposed to extend the breadth towards truly reusable Everything-as-a-Service (XaaS) registration entries. Despite the proposals, there is a shortage of capable and extensible XaaS registries. In this paper, we present such a system and share our experience in using it for service-related experiments.
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Paper Nr: 84
Title:

Exploiting Capacity Planning of Cloud Providers to Limit SLA Violations
Authors:

Nadia Ranaldo and Eugenio Zimeo
Abstract: Automatic negotiation of Service Level Agreements (SLAs) is a promising way to stipulate contracts in the Cloud market, where the high dynamicity of customers' requirements and providers' resources availability make it very difficult to statically define Quality of Service (QoS) level and pricing. To achieve high satisfaction levels for both parties, the negotiation decisions about stipulation conditions (or rejection) of contracts should be guided both by an overall strategic business policy and by dynamic information. In this paper, we propose to exploit capacity planning to support bilateral negotiation processes with the aim of optimizing the overall utility for service providers, by avoiding contracts that could incur in SLAs violations, keeping, at the same time, competitive service prices. In particular, the proposed technique exploits a heuristic algorithm to automatically evaluate a non-additive utility function and the acceptable region, taking into account QoS, resources availability, costs and penalties. The technique is compared with static approaches by using some simulations.
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Short Papers
Paper Nr: 68
Title:

CloudSurfer - A Cloud Broker Application for Security Concerns
Authors:

Milena Frtunic, Filip Jovanovic, Mladen Gligorijvic, Lazar Dordevic, Srecko Janicijevic, Per Håkon Meland, Karin Bernsmed and Humberto Castejon
Abstract: The broker is foreseen to take an important role in the future Cloud ecosystem. A Cloud broker will simplify the relationships between Cloud providers and customers, by aggregating, integrating and customizing services in accordance to the customers’ needs. This paper demonstrates how security requirements can be a part of the Cloud brokering model. We present CloudSurfer, which is a prototype implementation of an independent Cloud broker that allows the customer to search for services that fulfill a set of security requirements. The application has been evaluated by representatives from the software industry and academia, and is freely available for further research.
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Paper Nr: 87
Title:

Cost and Risk Aware Support for Cloud SLAs
Authors:

Ming Jiang, James Byrne, Karsten Molka, Django Armstrong, Karim Djemame and Tom Kirkham
Abstract: Automated control of Cloud Service Level Agreements (SLA) is typically focused on Quality of Service (QoS) management and monitoring of the Cloud Infrastructure in-line with the SLA. Using risk assessments to bridge the needs of the Service Provider and Infrastructure Provider is one way in which the management of the whole Cloud SLA life-cycle can be achieved automatically. In this paper we adapt the QoS based risk approach and combine it with business orientated goal monitoring to improve the business input into the management of SLA from both a Cloud IP and SP perspective. We demonstrate this approach using probability of failure QoS risk linked to economic modelling of cost from the business goals of a SP.
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Paper Nr: 26
Title:

Managing the Cloud Service Lifecycle from the User’s View
Authors:

Beatrice Moltkau, Yvonne Thoss and Alexander Schill
Abstract: The concept of Cloud Computing has become indispensable in recent years. The use of distributed computing resources facilitates primarily infinite scalability and cost reductions by pay per use agreements. However, the management of cloud services is extensive with regard to the Cloud Service Lifecycle phases. The analysis of operational Cloud Management Systems showed that the scope of managing functionalities is too inconsistent. We present a guideline for the development of a Cloud Management System that supports the essential phases within the Cloud Service Lifecycle from the cloud provider’s and the consumer’s view.
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Paper Nr: 39
Title:

Rule-based Cloud Service Localisation
Authors:

Luke Collins, Frank Fowley and Claus Pahl
Abstract: The fundamental purpose of cloud computing is the ability to quickly provide software and hardware resources to global users. The main aim of cloud service localisation is to provide a method for facilitating the internationalisation and localisation of cloud services by allowing them to be adapted to different locales. We address lingual localisation by providing a service translation using the latest web-services technology to adapt services to different languages and currency conversion by using realtime data provided by the European Central Bank. Units and Regulatory Localisations are performed by a conversion mapping, which we have generated for a subset of locales. The aim is to provide a standardised view on the localisation of services by using runtime and middleware services to deploy a localisation implementation.
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Paper Nr: 67
Title:

OWL-LingS Editor - A Tool for Semantic Description of Linguistic Web Services
Authors:

Nabil Baklouti, Faten Fakhfakh, Bilel Gargouri and Mohamed Jmaiel
Abstract: We propose in this paper a tool called OWL-LingS (stands for OWL for Linguistic Services) Editor providing an augmented semantic description for Linguistic Web Services (LingWS for short). It supports an extension of OWL-S approach for representing non-functional linguistic properties. OWL-LingS uses a linguistic domain ontology in order to semantically annotate the LingWS elements.
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Area 3 - Cloud Computing Platforms and Applications

Full Papers
Paper Nr: 58
Title:

Characterising the Power Consumption of Hadoop Clouds - A Social Media Analysis Case Study
Authors:

Javier Conejero, Omer Rana, Peter Burnap, Jeffrey Morgan, Carmen Carrion and Blanca Caminero
Abstract: Energy efficiency is often identified as one of the key reasons for migrating to Cloud environments. It is often stated that a data centre hosting the Cloud environment is likely to achieve greater energy efficiency (at a reduced cost) compared to a local deployment. With increasing energy prices, it is also estimated that a large percentage of operational costs within a Cloud environment can be attributed to energy. In this work, we investigate and measure energy consumption of a number of virtual machines running the Hadoop system, over an OpenNebula Cloud. Our workload is based on sentiment analysis undertaken over Twitter messages. Our objective is to understand the tradeoff between energy efficiency and performance for such a workload. From our results we generalise and speculate on how such an analysis could be used as a basis to establish a Service Level Agreement with a Cloud provider – especially where there is likely to be a high level of variability (both in performance and energy use) over multiple runs of the same application (at different times).
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Paper Nr: 63
Title:

Hedging Cloud Energy Costs via Risk-free Provision Point Contracts
Authors:

Owen Rogers and Dave Cliff
Abstract: The cost of electricity is a major concern to public providers of cloud computing services. On-demand pricing, common amongst cloud providers, does not aid the provider in planning future demand and therefore purchasing energy at discounted rates. In this paper, we describe a number of advance pricing schemes for cloud computing resources based on provision-point contracts, commonly used by deal-of-the-day websites such as Groupon. We propose three models – Group Provision Points, Contributory Provision Points, and Variable Reward Forwards – that each reward consumers with reduced prices for advance reservations, while allowing providers to make accurate forecasts of energy usage. Furthermore, we show how the schemes are risk-free for the provider, guaranteeing to be at least as profitable as on-demand schemes. We present results from a simulation of the schemes, and compare the results to our analytically derived predictions.
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Paper Nr: 127
Title:

An HPC Application Deployment Model on Azure Cloud for SMEs
Authors:

Fan Ding, Dieter an Mey, Sandra Wienke, Ruisheng Zhang and Lian Li
Abstract: With the advance of high-performance computing (HPC), more and more scientific applications which cannot be satisfied by on-premises compute power need large scale of computing resources, especially for small and medium-sized enterprises (SMEs). Emerging cloud computing offerings promise to provide us with enormous on-demand computing power. Many cloud platforms have been developed to provide users with various kinds of computer and storage resources. The user only needs to pay for the required resources and does not need to struggle with the underlying configuration of the operation system. But it is not always convenient for a user to migrate on-premises applications to these cloud platforms, which is especially true for an HPC application. In this paper, we proposed an HPC application deployment model based on the Windows Azure cloud platform, and developed an MPI application case on Azure.
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Short Papers
Paper Nr: 51
Title:

A Resource Model for Cloud-based Workflow Management Systems - Enabling Access Control, Collaboration and Reuse
Authors:

Sebastian Görg, Ralph Bergmann, Sarah Gessinger and Mirjam Minor
Abstract: Cloud-based workflow management systems provide platforms for modeling and execution of workflows while offering the common benefits of cloud computing. Additionally, the opportunity for workflow reuse and collaborative modeling could support agile business, as better workflows can be created according to a particular demand of the business with less effort. This paper addresses the issue of workflow reuse and collaborative modeling within a community of users. We present a new resource model for workflow related resources as well as a proposal for an access control mechanism. The proposed methods are currently under development within the workflow management system CAKE.
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Paper Nr: 73
Title:

Workload Management for Dynamic Partitioning Schemes in Replicated Databases
Authors:

M. Louis-Rodríguez, J. Navarro, I. Arrieta-Salinas, A. Azqueta-Alzuaz, A. Sancho-Asensio and J. E. Armendáriz-Iñigo
Abstract: Recent advances on providing transactional support on the cloud rely on keeping databases properly partitioned in order to preserve their beloved high scalability features. However, the dynamic nature of cloud environments often leads to either inefficient partitioning schemes or unbalanced partitions, which prevents the resources from being utilized on an elastic fashion. This paper presents a load balancer that uses offline artificial intelligence techniques to come out with the optimal partitioning design and replication protocol for a cloud database providing transactional support. Performed experiments proof the feasibility of our approach and encourage practitioners to progress on this direction by exploring online and unsupervised machine learning techniques applied to this domain.
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Paper Nr: 80
Title:

Extending Cloud-based Object Storage with Content Centric Services
Authors:

Michael C. Jaeger, Alberto Messina, Spyridon V. Gogouvitis, Elliot K. Kolodner, Dimosthenis Kyriazis, Enver Bahar and Uwe Hohenstein
Abstract: Content centric storage refers to a paradigm where data objects are accessed by applications through information about their content, rather than their path in a hierarchical structure. Applications are relieved from having knowledge about the data store organization or the place in a (physical) storage hierarchy. Instead, applications can use metadata associated with objects in order to to query for the desired content. In this paper, we explain the new functionality added to our first version of the content centric storage (Jaeger et al., 2012): We present a new REST API for the management of relations and the ability to use schemas for enforcing metadata. The need for such a content centric storage is presented with examples from the media production domain.
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Paper Nr: 99
Title:

α BPaaS - A Customizable BPaaS on the Cloud
Authors:

Yehia Taher, Rafiqul Haque, Willem-jan van den Heuvel and Beatrice Finance
Abstract: With the emergence of the Internet technologies - notably, SOA and Cloud Computing - enterprises are increasingly delivering their business services through on-line service offerings called Business Process as a Service (BPaaS). However, current BPaaS offerings can be perceived as monolithic cloud solutions that are constrained by the capabilities that are made available by the provider at their delivery level and do not allow for easy extensibility or customization options. In this paper, we propose a novel BPaaS engineering techniques which cater for the tailoring of services to specific business needs using a mixture of SaaS, PaaS and IaaS solutions - possibly from various providers. It is the prime goal of our proposal to simplify the engineering of BPaaS applications by hiding the complexity of their development and deployment. This is achieved by providing a customization solution to manage all configuration of functional and non functional aspects related to a BPaaS offering.
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Paper Nr: 105
Title:

Conceptual Approach for Performance Isolation in Multi-tenant Systems
Authors:

Manuel Loesch and Rouven Krebs
Abstract: Multi-tenant applications (MTAs) share one application instance among several customers to increase the efficiency. Due to the tight coupling, customers may influence each other with regards to the performance they observe. Existing research focuses on methods and concrete algorithms to performance-isolate the tenants. In this paper, we present conceptual concerns raised when serving a high amount of users. Based on a load balancing cluster of multiple MTAs, we identified potential positions in an architecture where performance isolation can be enforced based on request admission control. Our discussion shows that different positions come along with specific pros and cons that have influence on the ability to performance-isolate tenants.
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Paper Nr: 111
Title:

Towards Cloud Data Management for MMORPGs
Authors:

Ziqiang Diao and Eike Schallehn
Abstract: Massively multiplayer online role-playing games (MMORPG) provide a persistent and collaborative world for millions of players. With increasing numbers of players and growing volumes of data, architectures based on conventional RDBMS limit the development of MMORPGs, because issues related to the availability and scalability of the storage system become a big challenge. These properties are typically well supported by Cloud data storage systems, while other typical requirements of MMOPRGs are not or not yet supported, as we will show in this paper. Furthermore, in a current project we assess the usability of Cassandra and possibly extend its functionality for MMORPGs. In this paper, we will classify data based on its management requirements, highlight limitations of the existing architecture and identify potentials and issues of Cassandra in the management of diverse data in MMORPGs.
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Paper Nr: 124
Title:

EUPaaS - Elastic Ubiquitous Platform as a Service for Large-scale Ubiquitous Applications
Authors:

Fei Li, Schahram Dustdar, Jakob Bardram, Martín Serrano, Manfred Hauswirth, Vasilios Andrikopoulos and Frank Leymann
Abstract: Large-scale ubiquitous computing applications are rapidly emerging in the fields of pervasive healthcare, smart cities and so on. They present unprecedented challenges to state-of-the-art ubiquitous systems in the respects of accommodating fluctuating user demands, handling volatile data quality and adaptation to complex system and user contexts. Driven by a motivating scenario in future mega-hospital environment, we propose to exploit the potential of cloud computing in supporting large-scale ubiquitous computing applications. This position paper will present the novel concept of EUPaaS (Elastic Ubiquitous Platform as a Service), outline the key research topics, and propose a cloud-based ubiquitous application platform.
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Paper Nr: 12
Title:

Cloud Utility Price Models
Authors:

Sururah A. Bello and Christoph Reich
Abstract: Cloud Computing’s service models have a number of proprietary pricing models as the services has been commoditized to some extent. The SaaS especially so far has been known with a flat price within the usage time. Pricing models need to be more flexible to prevent customers from thinking that paying same price for a service over a period is no more cost effective, in spite of the level of utilization of the service. For Cloud Computing this has to be taken into account. Africans have a business model with peculiarity. In order to expand the acceptability of Cloud Computing to the African market, this peculiarity must be accommodated. This study proposes cloud utility price models to give the Cloud customer the luxury of different usage style and determine a customer specific, individual, most suitable price model. It gives the customer the opportunity to choose a price model for the predicted usage and work within the budget.
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Paper Nr: 13
Title:

Octopus - A Redundant Array of Independent Services (RAIS)
Authors:

Christian Baun, Marcel Kunze, Denis Schwab and Tobias Kurze
Abstract: Cloud storage services such as the Amazon Simple Storage Service (S3) are widely accepted and are reaching an ever-expanding range of customers. Especially services providing S3-compatible interfaces enjoy great popularity due to S3’s simplistic, yet powerful approach to store and retrieve data via web protocols. While cloud storage services present a convenient tool, they also might turn into a risk for your data. Apart from planned service outages which may or may not be covered by Service Level Agreements (SLA), there is no guarantee that a service provider might go out of business. One might also imagine that data could be destroyed, lost or altered due to unplanned outages or physical disaster. One possibility to improve availability and also data robustness is to consume services of more than one cloud storage provider simultaneously and to establish a federated, redundant cloud storage system. Octopus cloud storage implements such a federated system realizing the concept of a Redundant Array of Independent Services (RAIS).
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Paper Nr: 27
Title:

ScaBIA: Scalable Brain Image Analysis in the Cloud

Authors:

Ali Gholami, Gert Svensson, Erwin Laure, Matthias Eickhoff and Götz Brasche
Abstract: The use of cloud computing as a new paradigm has become a reality. Cloud computing leverages the use of on-demand CPU power and storage resources while eliminating the cost of commodity hardware ownership. Cloud computing is now gaining popularity among many different organizations and commercial sectors. In this paper, we present the scalable brain image analysis (ScaBIA) architecture, a new model to run statistical parametric analysis (SPM) jobs using cloud computing. SPM is one of the most popular toolkits in neuroscience for running compute-intensive brain image analysis tasks. However, issues such as sharing raw data and results, as well as scalability and performance are major bottlenecks in the “single PC”-execution model. In this work, we describe a prototype using the generic worker (GW), an e-Science as a service middleware, on top of Microsoft Azure to run and manage the SPM tasks. The functional prototype shows that ScaBIA provides a scalable framework for multi-job submission and enables users to share data securely using storage access keys across different organizations.
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Paper Nr: 41
Title:

A Coordination Protocol for User-customisable Cloud Policy Monitoring
Authors:

Ming-Xue Wang, Lei Xu and Claus Pahl
Abstract: Cloud computing will see a increasing demand for end-user customisation and personalisation of multi-tenant cloud service offerings. Combined with an identified need to address QoS and governance aspects in cloud computing, a need to provide user-customised QoS and governance policy management and monitoring as part of an SLA management infrastructure for clouds arises. We propose a user-customisable policy definition solution that can be enforced in multi-tenant cloud offerings through an automated instrumentation and monitoring technique. We in particular allow service processes that are run by cloud and SaaS providers to be made policy-aware in a transparent way.
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Paper Nr: 45
Title:

Towards a Semantic Definition for a Cloud based Event Notification Service
Authors:

Marc Schaaf, Stella Gatziu Grivas and Arne Koschel
Abstract: We propose an Activity Service as a component in cloud computing. As a particular novelty we base this Activity Service on the well-defined and proven semantics of Active Database Management Systems (ADBMS) to overcome the challenges of developing portable cloud based event processing applications. As contribution of this paper we provide the first steps of the adaption of the ADBMS semantics to the distributed and highly dynamic environment of the cloud.
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Paper Nr: 46
Title:

Cloud based Services for Biomedical Image Analysis
Authors:

D. Wang, T. Bednarz, Y. Arzhaeva, P. Szul, S. Chen, N. Burdett, A. Khassapov, T. Gureyev and J. Taylor
Abstract: With the software as a service becoming an increasingly prevalent delivery model, we have developed a cloud-based image analysis toolbox to provide a wider user base with easy access to the software tools that we have developed over the last decade. This paper discusses our work on the design and implementation of the cloud-based image analysis and processing services on an Australian national cloud infrastructure, including their architecture, workflow management framework, image analysis and visualization examples, and the challenges we faced. Key components of the services are described, showing the capabilities of the service engine for real-world cloud-based biomedical image analysis applications.
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Paper Nr: 52
Title:

Analysis Cloud - Running Sensor Data Analysis Programs on a Cloud Computing Infrastructure
Authors:

Jan Sipke van der Veen, Bram van der Waaij, Matthijs Vonder, Marc de Jonge, Elena Lazovik and Robert Meijer
Abstract: Sensors have been used for many years to gather information about their environment. The number of sensors connected to the internet is increasing, which has led to a growing demand of data transport and storage capacity. In addition, evermore emphasis is put on processing the data to detect anomalous situations and to identify trends. This paper presents a sensor data analysis platform that executes statistical analysis programs on a cloud computing infrastructure. Compared to existing batch and stream processing platforms, it adds the notion of simulated time, i.e. time that differs from the actual, current time. Moreover, it adds the ability to dynamically schedule the analysis programs based on a single timestamp, recurring schedule, or on the sensor data itself.
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Paper Nr: 59
Title:

Implementation and Operation of User Defined Network on IaaS Clouds using Layer 3 Overlay
Authors:

Ryo Nakamura, Yuji Sekiya and Hiroshi Esaki
Abstract: Server virtualization technology achieves ”Infrastructure as a Service (IaaS)” model services. Anyone can use virtual server resource easily without preparing computer hardware, thus IaaS environments provides multiple operational benefits to users. Therefore, today various types of users, both of personal users and enterprises users, deploy virtual resources on IaaS cloud. On the other hand, many enterprise users still have their own environments and operate them by themselves (i.e, on-premise environments). When they migrate the services from physical facilities to IaaS clouds, they have two problems. The first problem is that services are bound to IP addresses. The second problem is lack of flexibility in network design and management on IaaS clouds. To solve these problems, we propose an operation model to migrate on-premise services to IaaS clouds using LISP and VXLAN. Using our proposed method, users can migrate IP addresses and services among IaaS clouds. In this paper, we proposed new migration method of IP address among IaaS clouds and implemented the method using LISP and VXLAN software on Linux systems. Then we evaluate performance of our system and present a operation on actual IaaS clouds.
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Paper Nr: 70
Title:

Towards Virtualization of Rich Applications for Distribution under a SaaS Model
Authors:

D. A. Rodriguez-Silva, L. Adkinson-Orellana, V. Fernandez-Diaz and F. J. Gonzalez-Castaño
Abstract: Current mobile devices (smartphones, tablets, netbooks…), widely used nowadays, can run potent native applications, but they cannot support typical desktop applications from any operating system. Since modern devices support recent web standards as HTML5, it is possible to develop a solution based on a thin web client to grant remote access to desktop applications offered under a SaaS model. This paper proposes the development of an innovative remote desktop system able to detect application content and encode it efficiently in real-time, to support an optimal visualization on clients, combining both remote desktop and streaming protocols. The system is hosted by a cloud infrastructure that ensures scalability, and it follows a pay-per-use model. Application providers can include their software in a dynamic cloud repository, from where it is launched remotely to meet final user demands.
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Paper Nr: 85
Title:

Remote Laboratories in the Cloud - A Digital Holographic Microscope
Authors:

Wolfgang Osten, Giancarlo Pedrini and Marc Wilke
Abstract: Cloud computing introduces a new paradigm for using IT resources, the often quoted “everything as a service”, where resources are leased and paid for on a time-limited ad-hoc basis. Related advances in information technology open up the potential of combining optical systems with net based infrastructures, allowing for remote inspection and virtual metrology. Coupling the cloud to physically existent laboratories provides universal access to non-virtual resources. In this paper, we report our recent work on building a remote laboratory for digital holographic metrology. We describe the architecture and the techniques involved in setting up the remote controlling metrology system. Further consideration will be given to the integration into an advanced infrastructure for remote experimentation, data storage and publication.
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Paper Nr: 109
Title:

Continuous Service Optimization as Cloud Brokerage Service
Authors:

Stamatia Rizou, Yiannis Verginadis and Gregoris Mentzas
Abstract: As cloud service ecosystems evolve, cloud service brokerage systems have emerged as intermediaries between cloud service consumers and cloud providers to preserve and enhance user expectations. In this paper, we describe the functionalities of a cloud brokerage tool that assist cloud brokers to ensure an optimized cloud service selection both during cloud on boarding and operation phases. To this end, we present an optimisation lifecycle providing customized continuous optimisation of cloud service selection and we explain the role of the cloud broker within this service optimization loop.
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Paper Nr: 116
Title:

Position Paper: Multi-tenants Context-aware Service Composition in Cloud Computing
Authors:

Wael Sellami, Hatem Hadj Kacem and Ahmed Hadj Kacem
Abstract: Cloud computing has gained a momentum by providing multi-tenancy utility and applications as a service. The power of services occurs in the ability to combine different services in order to obtain a composed service. Context-aware cloud service is anticipated to bring an innovation in mobile computing. Therefore the composed service can be a multi-tenant context-aware, scalable and adaptable. In this paper, we define the problem of coupling context-aware cloud service composition with multi-tenancy in the cloud and we determine crucial challenges that can be solved. For that, we propose an approach to enable multiple providers to run their composed services within the same instance, with different contexts and without modifications of the workflows.
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Area 4 - Cloud Computing Enabling Technology

Full Papers
Paper Nr: 19
Title:

Engineering Service Level Agreements - A Constrained-domain and Transformation Approach
Authors:

Josef Spillner, Stefan Illgen and Alexander Schill
Abstract: Service Level Agreements (SLAs) are fundamental technical-juridical documents which in their function as contract govern the rights and obligations between service consumers and providers. In today’s growing service ecosystems, individually negotiated SLAs have powerful additional roles such as serving as the input for automated service monitoring and health checking as well as binding service consumers through custom incentives. These advantages, in turn, require adequate engineering techniques to let service providers express the conditions under which a service can be consumed. While many SLA languages and tools exist, existing approaches are either severely limited or too complex to be used by a broad set of providers. Hence, we present a reduced effort approach based on transformations from existing domain-constrained public service descriptions. By demonstrating the application thereof in an Infrastructure-as-a-Service scenario, we show that SLAs can be prepared and improved in a very short time with suitable tools.
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Paper Nr: 24
Title:

A Secure Dynamic Collaboration Environment in a Cloud Context
Authors:

Chris Piechotta, Adam Enø Jensen, Martin Grooss Olsen, Joey W. Coleman and Peter Gorm Larsen
Abstract: In recent years, the cloud has emerged as an attractive means for hosting and delivering services over the Internet. This has resulted in a renewed focus on information security in the case where data is stored in the virtual space of the cloud and is not physically accessible to the customer. This paper addresses the increasing security concerns of migrating to the cloud and utilising it for data storage, focusing on securing data in an untrusted cloud environment and ensuring detailed data access control in the cloud.
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Paper Nr: 25
Title:

Migrating to the Cloud - A Software Product Line based Analysis
Authors:

Jesús García-Galán, Omer Rana, Pablo Trinidad and Antonio Ruiz-Cortés
Abstract: Identifying which part of a local system should be migrated to a public Cloud environment is often a difficult and error prone process. With the significant (and increasing) number of commercial Cloud providers, choosing a provider whose capability best meets requirements is also often difficult. Most Cloud service providers offer large amounts of configurable resources, which can be combined in a number of different ways. In the case of small and medium companies, finding a suitable configuration with the minimum cost is often an essential requirement to migrate, or even to initiate the decision process for migration. We interpret this need as a problem associated with variability management and analysis. Variability techniques and models deal with large configuration spaces, and have been proposed previously to support configuration processes in industrial cases. Furthermore, this is a mature field which has a large catalog of analysis operations to extract valuable information in an automated way. Some of these operations can be used and tailored for Cloud environments. We focus in this work on Amazon Cloud services, primarily due to the large number of possible configurations available by this service provider and its popularity. Our approach can also be adapted to other providers offering similar capabilities.
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Paper Nr: 71
Title:

A Semantic Model to Support Security Matching in Cloud Environments
Authors:

Giuseppe Di Modica and Orazio Tomarchio
Abstract: Despite its technological advances, cloud computing's adoption is not as wide as expected. Security is still a big concern that prevents many to ``cloudify'' their applications and put their data in the hands of a cloud provider. Also, interoperable scenarios fostered by SOA technologies exacerbate the security question, as customers have to deal with multiple providers who, in their turn, must establish mutual trust relationships in order to interoperate. In the last few years, policies are being used as a means to build networks of trustiness among cloud providers. Standards and specifications on security management through policies have also appeared. We argue that the main problem with this approach is that policies are expressed through syntactic languages which, if processed by computers, show well-known limitations. We then propose an approach that leverages on the semantic technologies to enrich security policies with semantic contents enabling machine reasoning. The framework we developed caters for the security needs of both customers and providers, and aims at making a smart match between what is requested and what is offered in terms of security. On the user side, no extra effort is required than specifying their security policies according to well-established security notations; an automatic procedure is committed to adding semantic content to the policies.
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Paper Nr: 76
Title:

Integrating Configuration Management with Model-driven Cloud Management based on TOSCA
Authors:

Johannes Wettinger, Michael Behrendt, Tobias Binz, Uwe Breitenbücher, Gerd Breiter, Frank Leymann, Simon Moser, Isabell Schwertle and Thomas Spatzier
Abstract: The paradigm of Cloud computing introduces new approaches to manage IT services going beyond concepts originating in traditional IT service management. The main goal is to automate the whole management of services to reduce costs and to make management tasks less error-prone. Two different service management paradigms are used in practice: configuration management and model-driven Cloud management. The latter one aims to be a holistic management approach for services in the Cloud. However, both management paradigms are originating in different backgrounds, thus model-driven Cloud management does not cover all aspects of configuration management that are key for Cloud services. This paper presents approaches for integrating configuration management with model-driven Cloud management and how they can be realized based on the OASIS Topology and Orchestration Specification for Cloud Applications and Chef, a popular configuration management tool. These approaches enable the creation of holistic and highly portable service models.
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Paper Nr: 128
Title:

Practical Aspects for Effective Monitoring of SLAs in Cloud Computing and Virtual Platforms
Authors:

Ali Imran Jehangiri, Edwin Yaqub and Ramin Yahyapour
Abstract: Cloud computing is transforming the software landscape. Software services are increasingly designed in modular and decoupled fashion that communicate over a network and are deployed on the Cloud. Cloud offers three service models namely Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS), and Softwareas- a-Service (SaaS). Although this allows better management of resources, the Quality of Service (QoS) in dynamically changing environments like Cloud must be legally stipulated as a Service Level Agreement (SLA). This introduces several challenges in the area of SLA enforcement. A key problem is detecting the root cause of performance problems which may lie in hosted service or deployment platforms (PaaS or IaaS), and adjusting resources accordingly. Monitoring and Analytic methods have emerged as promising and inevitable solutions in this context, but require precise real time monitoring data. Towards this goal, we assess practical aspects for effective monitoring of SLA-aware services hosted in Cloud. We present two real-world application scenarios for deriving requirements and present the prototype of ourMonitoring and Analytics framework. We claim that this work provides necessary foundations for researching SLA-aware root cause analysis algorithms under realistic setup.
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Short Papers
Paper Nr: 22
Title:

Adaptable Service Level Objective Agreement (A-SLO-A) for Cloud Services
Authors:

Stefan Frey, Claudia Lüthje, Ralf Teckelmann and Christoph Reich
Abstract: Reducing IT costs by using Cloud Computing is tempting for start up companies. To attract companies to outsource their services to Clouds, Cloud provider need to offer Service Level Objectives specified in SLAs individually for their customers. Cloud provider like Amazon can not afford to negotiate individual SLAs manually. Therefore, it becomes important to develop a format for machine-readable SLAs which can easily adapt to the individual Service Level Objectives requested by the customer any time. Because of its adaptability at run time by each individual customer on demand, this comply with the characteristics of Cloud Computing and to satisfies the customer’s requirements to be flexible. This paper describes an adaptable Service Level Objective Agreement (A-SLO-A) format being machine-processed to offer the possibility to integrate the SLA management into the highly automated processes of resource provisioning. Use cases show its applicability.
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Paper Nr: 53
Title:

Precise VM Placement Algorithm Supported by Data Analytic Service
Authors:

Dapeng Dong and John Herbert
Abstract: The popularity and commercial use of cloud computing has prompted an increased concern among cloud service providers for both energy efficiency and quality of service. One of the key techniques used for the efficient use of cloud server resources is virtual machine placement. This work introduces a precise VM placement algorithm for power conservation and SLA violation prevention. The mathematical model of the algorithm is supported by a sophisticated data analytic system implemented as a service. The precision of the algorithm is achieved by allowing each individual VM to build, on demand, its own data model over an appropriate time horizon. Thus the data model can reflect the characteristics of resource usage of the VM accurately. The algorithm can communicate synchronously or asynchronously with the data analytic service which is deployed as a cloud-based solution. In the experiments, several advanced data modelling and use forecasting techniques were evaluated. Results from simulation-based experiments show that the VM placement algorithm (supported by the data analytic service) can effectively reduce power consumption, the number of VM migrations, and prevent SLA violation; it also compares favourably with other heuristic algorithms.
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Paper Nr: 61
Title:

Achieving Energy Efficiency and Security in Mobile Cloud Computing
Authors:

Sourya Joyee De, Sourav Saha and Asim K. Pal
Abstract: Computation offloading to the Cloud for energy efficiency in portable devices is an emerging area of research triggered by the widespread use and acceptance of smart phones. A number of architectures have already been proposed in this context. However, security issues in the cloud still remain a concern that can play an important role in deciding whether offloading really helps to achieve energy efficiency in mobile phones. Our framework is based on a layered data approach together with user selected security policies. This motivated us to develop a mathematical model to depict the energy consumption when performing a security-enhanced computation in the cloud. The model demonstrates the potential energy saving in the event of user or organization specified policy for secure computing and data storage in the Cloud.
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Paper Nr: 75
Title:

Pattern-based Runtime Management of Composite Cloud Applications
Authors:

Uwe Breitenbücher, Tobias Binz, Oliver Kopp and Frank Leymann
Abstract: The management of composite Cloud applications is a challenging problem as current available technologies provide management solutions that are tightly coupled to individual applications. Reusing and transferring management knowledge from one application to another in an automated way is a major issue. In this paper, we present a pattern-based approach which enables the decoupling of high level and low level management knowledge and show how both can be applied together fully automated to various kinds of applications.
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Paper Nr: 83
Title:

Detecting VM Live Migration using a Hybrid External Approach
Authors:

Sebastian Fiebig, Melanie Siebenhaar, Christian Gottron and Ralf Steinmetz
Abstract: Cloud computing has become a paradigm of our time. It is not only a technical solution, but a business model to sell and rent computing power and servers. Virtual machines (VMs) are used to allow a dynamic and transparent server utilization, which is made possible by VM live migration. VM live migration allows to move VMs within and out of data centers while the VM is still running. Thus, resource usage becomes more efficient. However, VM live migration also provides an opportunity for new attack vectors, which can be used by malicious attackers. They can compromise hypervisors and afterwards steal VMs from data centers to gain control over resources. In the worst case scenario, the theft remains undetected by both system administrators and customers. In this paper, we present the first taxonomy of possible VM live migration detection approaches. There are two different monitoring approaches, i.e., internal or external monitoring, as well as different detection approaches, which correspond to the different approaches to detect migration. Moreover, we propose a hybrid external approach using delay measurement with ICMP ping and time-lag detection with the network time protocol (NTP) to detect VMlive migration. We show that VM live migration can be detected by using a prototype of our hybrid external approach.
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Paper Nr: 89
Title:

Verifying the Availability of Cloud Applications
Authors:

Melanie Siebenhaar, Olga Wenge, Ronny Hans, Hasan Tercan and Ralf Steinmetz
Abstract: Cloud-based services provide a high level of flexibility and eliminate large up-front IT investments by trading capital expenditure for operational expenditure. However, performance, availability, and security still remain dominant barriers when deciding whether to move to the cloud or not. Although cloud providers already try to tackle these issues by offering SLAs and corresponding monitoring solutions, the ability of these solutions to control the performance of cloud-based services is still considered as unsatisfactory by consumers. In this paper, we present an approach for verifying availability guarantees from a consumer’s perspective, since availability is one of the very few performance parameters that is considered in the SLAs of today’s cloud providers. The aim of our research is to facilitate the verification of performance guarantees independently from a cloud provider, which will help to increase cloud service adoption in the future.
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Paper Nr: 90
Title:

CloudTops: Latency Aware Placement of Virtual Desktops in Distributed Cloud Infrastructures
Authors:

Nishio Yamada, Toshiyuki Moritsu, Kaustubh Joshi, Matti Hiltunen and Richard Schlichting
Abstract: Latency sensitive interactive applications, such as virtual desktops for enterprise workers, are important applications for next generation cloud infrastructures. Determining where to geographically place desktop VMs in a globally distributed cloud so as to optimize user-perceived performance is an important and challenging problem. Historically, the performance of thin-client-based systems has been predominantly characterized in terms of the front-end network link between the thin client and the desktop. In this paper, we show that for typical enterprise applications, back-end network connectivity to the filesystems and applications that support the desktop can be equally important, and that the optimal balance between the front-end and back-end links depends on the precise workload. To help make dynamic decisions about desktop VM placement, we propose a per-user model that can be used to predict the optimal location for a user’s desktop. Experimental evaluation using several typical enterprise applications shows that our methodology can accurately predict which of many distributed data centers to use for a particular user’s workload even if details of the precise applications are not known.
Paper Nr: 96
Title:

Policy-based Security Provisioning and Performance Control in the Cloud
Authors:

Viswanath Nandina, José Marcio Luna, Edward J. Nava, Christopher C. Lamb, Gregory L. Heileman and Chaouki T. Abdallah
Abstract: In this paper we describe the development of a system that provides security provisioning and performance controls over content in a cloud environment. Using an approach grounded in Usage Management and Control theory we are able to successfully provision resources in multiple cloud systems. Providing increased security comes with a cost of reduced performance. Therefore a variable performance control model for different levels of security is proposed. This control model allocates Virtual Machines adaptively so that a desired performance measure lies between predefined upper and lower bounds as agreed in the Service Level Agreement.
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Paper Nr: 66
Title:

Modeling a Load-adaptive Data Replication in Cloud Environments
Authors:

Julia Myint and Axel Hunger
Abstract: Replication is an essential cornerstone of cloud storage where 24x7 availability is needed. Failures are normal rather than exceptional in the cloud computing environments. Aiming to provide high reliability and cost effective storage, replicating based on data popularity is an advisable choice. Before committing a service level agreement (SLA) to the customers of a cloud, the service provider needs to carry out analysis of the system on which cloud storage is hosted. Hadoop Distributed File System (HDFS) is an open source storage platform and designed to be deployed in low-cost hardware. PC Cluster based Cloud Storage System is implemented with HDFS by enhancing replication management scheme. Data objects are distributed and replicated in a cluster of commodity nodes located in the cloud. In this paper, we propose a Markov chain model for replication system which is able to adapt the load changes of cloud storage. According to the performance evaluation, the system can be able to adapt the different workloads (i.e data access rates) while maintaining the high reliability and long mean time to absorption.
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Paper Nr: 72
Title:

A Contingency Model for Assessing Cloud Composite Capabilities
Authors:

Noel Carroll, Markus Helfert and Theo Lynn
Abstract: Cloud computing present new economic and flexible business and technological models. The explosive uptake of cloud solutions has fuelled the growth of cloud service providers (CSP). However, recent development show that within the field of cloud computing there is often too much focus on technology solutions but little insight on cloud exploitation and service analytics from a business perspective. To support CSPs and cloud users, it is critical that sourcing decisions are informed to align cloud strategy and service capabilities. In this paper we present a contingency model which supports the assessment of cloud composite capabilities. While we develop an understanding of the research gaps which exists throughout academic and industry literature, the contribution of this paper is the introduction of our contingency model which forms the initial development of the Cloud Service Index (CSI). The CSI is a basis to assess cloud composite capabilities.
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Paper Nr: 108
Title:

Clustering the Cloud - A Model for (Self-)Tuning of Cloud Data Management Systems
Authors:

Siba Mohammad, Eike Schallehn and Sebastian Breß
Abstract: Popularity and complexity of cloud data management systems are increasing rapidly. Thus providing sophisticated features becomes more important. The focus of this paper is on (self-)tuning where we contribute the following: (1) we illustrate why (self-)tuning for cloud data management is necessary but yet a much more complex task than for traditional data management, and (2) propose an model to solve some of the outlined problems by clustering nodes in zones across data management layers for applications with similar requirements.
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Paper Nr: 114
Title:

Boosting Performance and Scalability in Cloud-deployed Databases
Authors:

J. E. Armendáriz-Iñigo, J. Legarrea, J. R. González de Mendívil, A. Azqueta-Alzúaz, M. Louis-Rodriguez, I. Arrieta-Salinas and F. D. Muñoz-Escoí
Abstract: Eventual consistency improves the scalability of large datasets in cloud systems. We propose a novel technique for managing different levels of replica consistency in a replicated relational DBMS. To this end, data is partitioned and managed by a partial replication protocol that is able to define a hierarchy of nodes with a lazy update propagation. Nodes in different layers of the hierarchy may maintain different versions of their assigned partitions. Transactions are tagged with an allowance parameter k that specifies the maximum degree of data outdatedness tolerated by them. As a result, different degrees of transaction criticality can be set and non-critical transactions may be completed without blocking nor compromising the critical ones.
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