Werner Mach

A Consumer-Provider Cloud Cost Model Considering Variable Cost

This paper represents an analytical economic cost model for cloud computing aiming at comprising all kinds of cost of a commercial environment. To extend conventional state of- the-art models considering only fixed cost, we developed a concise, but comprehensive analytical model which does not only include fixed cost, but also variable cost allowing for the development and evaluation of business strategies for cloud environments. These strategies can be used for both, cloud providers and cloud consumers. The major goal of our model is to comprise all important economic fundamentals and methods. Thus, this new model supports the decision-making process to be applied with business cases and enables cloud consumers and cloud providers to determine their own business strategies and to analyze the respective impact on their business. Based on this model, the energy efficiency of cloud systems can also be evaluated according to chosen business models.

A generic negotiation and re-negotiation framework for consumer-provider contracting of web services

Electronic contracting is key issue for establishing liquid markets dealing with electronic goods. This paper presents a framework for automatic negotiation between Web services. The major goal of the framework is comprising all necessary components for negotiation and re-negotiation. The capabilities and the components are described both for Web service consumer and provider. The re-negotiation framework is based on independent control loops and associated knowledge bases for consumer and provider implementing specific business strategies. An economic cost model considering variable cost and a business rule repository are main parts of the knowledge bases. Furthermore the framework can handle auctioning by using predefined workflows as so called auctioning plug-ins.

Toward an economic and energy‐aware cloud cost model

This paper represents an economic cost model for cloud computing aiming at comprising all kinds of cost of a commercial environment. To extend conventional state‐of‐the‐art models considering only fixed cost, we developed a concise but comprehensive analytical model, which includes also variable cost allowing for the development and evaluation of business strategies for cloud environments. These strategies can be used for both cloud providers and cloud consumers. The major goal of our model is to comprise all important economic fundamentals and methods. Thus, this new model supports the decision‐making process to be applied with business cases and enables cloud consumers and cloud providers to define their own business strategies and to analyze the respective impact on their business. On the basis of this model, also, the energy efficiency of cloud systems can be evaluated according to chosen business models. Copyright

Bazaar-Extension: A CloudSim Extension for Simulating Negotiation Based Resource Allocations

Negotiation processes taking place between two or more parties need to agree on a viable execution mechanism. Auctioning protocols have proven useful as electronic negotiation mechanisms in the past. Auctions are a way of determining the price of a resource in a dynamic way. Additionally, auctions have well defined rules such as winner and loser determination, time restrictions or minimum price increment. These restrictions are necessary to ensure fair and transparent resource allocation. However, these rules are limiting flexibility of consumers and providers. In this paper we introduce a novel negotiation based resource allocation mechanisms using the offer-counteroffer negotiation protocol paradigm. This allocation mechanism shows similarities to the supermarket approach as consumer and provider are able to communicate directly. Further, the price is determined in a dynamic way similar to auctioning. We developed a Bazaar-Extension for CloudSim which simulates negotiation processes with different strategies. In this paper we introduce and analyze a specific Genetic Algorithm based negotiation strategy. For the comparison of the efficiency of resource allocations a novel Bazaar-Score was used.

A negotiation-based resource allocation model in IaaS-markets

Usually, IaaS providers use the inflexible supermarket approach for trading resources: a provider offers a resource for a fixed price and consumers can buy the offered resources without negotiating with the provider (take it or leave it). Another possibility is an auction based approach. Auctions have well defined rules which are necessary to ensure fair and transparent resource allocation. However, these rules are limiting flexibility of consumers and providers. In this paper we present a negotiation based resource allocation mechanism following the offer-counteroffer negotiation protocol paradigm. On the one hand, this allocation mechanisms is similar to the supermarket approach as consumer and provider are able to communicate directly. On the other hand, the approach shows also similarities to auctions as the price is determined in a dynamic way. For justification and evaluation we developed a so called Bazaar-Extension for CloudSim which allows to run negotiations and to develop and simulate new negotiation strategies and market scenarios. Further a negotiation strategy considering basic economical principles is introduced in this paper which was used for an exemplary resource allocation scenario. The scenario shows that negotiation based resource allocation can improve the well-being of consumer and provider.

A Forecasting and Decision Model for Successful Service Negotiation

Future e-business models will rely on electronic contracts which are agreed dynamically and adaptively by web services. Thus, the automatic negotiation of Service Level Agreements (SLAs) between consumers and providers is key for enabling service-based value chains. The process of finding appropriate providers for web services seems to be simple. Consumers contact several providers and take the provider which offers the best matching SLA. However, currently consumers are not able forecasting the probability of finding a matching provider for their requested SLA. So consumers contact several providers and check if their offers are matching. In case of continuing faults, on the one hand consumers may adapt their Service Level Objects (SLOs) of the required SLA or on the other hand simply accept offered SLAs of the contacted providers. Thus, this paper proposes an analytical forecast model, which allows consumers to get an assessment of the probability to find matching providers. Additionally, we present an optimization algorithm based on the forecast results, which allows adapting the SLO parameter ranges in order to find at least one matching provider. Not only consumers, but also providers can use this forecast model to predict the prospective demand. So providers are able to assess the number of potential consumers based on their offers too. Justification of our approach is done by simulation of practical examples checking our theoretical findings.

Towards a Smart Webservice Marketplace

Electronic contracts are crucial for future e-Business models due to the increasing importance of Web services and the cloud as a reliable commodity enabling service-based value chains. Negotiation is the prerequisite for establishing a contract between two or more partners. These contracts are usually based on Service Level Agreements (SLAs). In this paper we present the framework of a smart Web service marketplace, which allows for automatic, autonomous, and adaptive negotiation and re-negotiation of Web services based on economic principles. Our approach enables market based service trading following a bazaar style and extends the classical supermarket approach typical for service negotiation today. We extend the WS-Agreement standard by feasible workflows to support auctioning for negotiation and re-negotiation. A specific highlight of our framework is the mapping of business strategies defined by economic goals of the respective organization into an ICT enabled framework. It facilitates autonomic agents acting as organizational representatives stipulating SLAs without human interaction. This allows for business transactions transparently to the environment but adhering to business objectives of the originating organization.

Parallel Algorithms for the Execution of Relational Database Operations Revisited On Grids

This paper presents an analytical discussion of algorithms for relational database operations in a grid environment, compares the findings with the classical generalized multiprocessor framework, and describes an optimization algorithm to maximize performance for a heterogeneous environment. We develop a concise but comprehensive analytical model of parallel algorithms for sorting, joining, and aggregation. In our approach we focus on a limited number of characteristic parameters to keep the analytical model clear. It is shown that an expressive model can be built upon just three characteristic parameter sets, namely the node processing performance and the network and the disk bandwidths. These parameters are the input for the optimization process for the orchestration of the execution workflow on the grid. Based on these results the paper proves that using smart enhancement to exploit the heterogeneity of the grid, the performance of the algorithms for database operations can be increased remarkably.

A classification of autonomous bilateral cloud SLA negotiation strategies

Currently digital markets emerge where cloud resources are traded in the form of computational services. Usually the so called supermarket approach is applied on these service markets, where consumers buy offered services from providers based on fixed functional and non-functional characteristics without negotiations. However, bilateral multi round negotiation, which allows to customize the traded services, is considered as a promising improvement to the static supermarket approach aiming for higher market efficiency. In this paper we introduce a novel generic service market ecosystem from which requirements for bilateral negotiation strategies are derived. Evaluating a survey on published bilateral negotiation strategies along these requirements shows that important market elements are not considered in current research. Most of the published bilateral negotiation strategies are focusing on a single negotiation phases only neglecting the complete negotiation process. Hence we classify the identified strategies along the different phases of the generic negotiation process. Based on our analysis we identify two different groups in their scientific approach: One group assumes complete information during bilateral negotiations while the other group assumes incomplete information.

Bazaar-Score: A Key Figure Measuring Market Efficiency in IaaS-Markets

Today’s economy creates the need for dynamic, adaptive and autonomous building of enterprise value chains consisting of arbitrary virtualized computing resources, as hardware and software services. The current key technology for service provisioning is the cloud computing framework. In the course of this development digital service markets are becoming business reality.