1,254 research outputs found
Fruit fly optimization algorithm for network-aware web service composition in the cloud
Service Oriented Computing (SOC) provides a framework for the realization of loosely coupled service oriented applications. Web services are central to the concept of SOC. Currently, research into how web services can be composed to yield QoS optimal composite service has gathered significant attention. However, the number and spread of web services across the cloud data centers has increased, thereby increasing the impact of the network on composite service performance experienced by the user. Recently, QoS-based web service composition techniques focus on optimizing web service QoS attributes such as cost, response time, execution time, etc. In doing so, existing approaches do not separate QoS of the network from web service QoS during service composition. In this paper, we propose a network-aware service composition approach which separates QoS of the network from QoS of web services in the Cloud. Consequently, our approach searches for composite services that are not only QoS-optimal but also have optimal QoS of the network. Our approach consists of a network model which estimates the QoS of the network in the form of network latency between services on the cloud. It also consists of a service composition technique based on fruit fly optimization algorithm which leverages the network model to search for low latency compositions without compromising service QoS levels. The approach is discussed and the results of evaluation are presented. The results indicate that the proposed approach is competitive in finding QoS optimal and low latency solutions when compared to recent techniques
Empowering Services based Software in the Digital Single Market to Foster an Ecosystem of Trusted, Interoperable and Legally Compliant Cloud-Services
The software industry has evolved from software on the shelf based applications deployed in dedicated servers , to Software as a service based components running on public or private Clouds and now to Cloud Service Brokers So, Cloud service brokerages have emerged as digital intermediaries in the information technology (IT) services market (Shang, 2013), creating value for cloud computing clients and vendors alike. This paper presents an approach to foster next generation cloud service brokers through an ecosystem of trusted, interoperable and legally compliant cloud services through an added value Cloud Services intermediator. This ecosystem will offer, create, consume and assess trusted, interoperable, and standard Cloud Services, where to (semi-)automatically deploy the next generation service based software applications.This work has been partially funded by the European
project Cloud for Europe (Seventh Framework
Programme for research,
technological development and demonstration under
grant agreement no 610650) and OPERANDO
(Horizon 2020 Programme, under grant agreement
no 653704)
Elastic Business Process Management: State of the Art and Open Challenges for BPM in the Cloud
With the advent of cloud computing, organizations are nowadays able to react
rapidly to changing demands for computational resources. Not only individual
applications can be hosted on virtual cloud infrastructures, but also complete
business processes. This allows the realization of so-called elastic processes,
i.e., processes which are carried out using elastic cloud resources. Despite
the manifold benefits of elastic processes, there is still a lack of solutions
supporting them.
In this paper, we identify the state of the art of elastic Business Process
Management with a focus on infrastructural challenges. We conceptualize an
architecture for an elastic Business Process Management System and discuss
existing work on scheduling, resource allocation, monitoring, decentralized
coordination, and state management for elastic processes. Furthermore, we
present two representative elastic Business Process Management Systems which
are intended to counter these challenges. Based on our findings, we identify
open issues and outline possible research directions for the realization of
elastic processes and elastic Business Process Management.Comment: Please cite as: S. Schulte, C. Janiesch, S. Venugopal, I. Weber, and
P. Hoenisch (2015). Elastic Business Process Management: State of the Art and
Open Challenges for BPM in the Cloud. Future Generation Computer Systems,
Volume NN, Number N, NN-NN., http://dx.doi.org/10.1016/j.future.2014.09.00
Executing Bag of Distributed Tasks on the Cloud: Investigating the Trade-offs Between Performance and Cost
Bag of Distributed Tasks (BoDT) can benefit from decentralised execution on
the Cloud. However, there is a trade-off between the performance that can be
achieved by employing a large number of Cloud VMs for the tasks and the
monetary constraints that are often placed by a user. The research reported in
this paper is motivated towards investigating this trade-off so that an optimal
plan for deploying BoDT applications on the cloud can be generated. A heuristic
algorithm, which considers the user's preference of performance and cost is
proposed and implemented. The feasibility of the algorithm is demonstrated by
generating execution plans for a sample application. The key result is that the
algorithm generates optimal execution plans for the application over 91\% of
the time
DATESSO: Self-Adapting Service Composition with Debt-Aware Two Levels Constraint Reasoning
The rapidly changing workload of service-based systems can easily cause
under-/over-utilization on the component services, which can consequently
affect the overall Quality of Service (QoS), such as latency. Self-adaptive
services composition rectifies this problem, but poses several challenges: (i)
the effectiveness of adaptation can deteriorate due to over-optimistic
assumptions on the latency and utilization constraints, at both local and
global levels; and (ii) the benefits brought by each composition plan is often
short term and is not often designed for long-term benefits -- a natural
prerequisite for sustaining the system. To tackle these issues, we propose a
two levels constraint reasoning framework for sustainable self-adaptive
services composition, called DATESSO. In particular, DATESSO consists of a re
ned formulation that differentiates the "strictness" for latency/utilization
constraints in two levels. To strive for long-term benefits, DATESSO leverages
the concept of technical debt and time-series prediction to model the utility
contribution of the component services in the composition. The approach embeds
a debt-aware two level constraint reasoning algorithm in DATESSO to improve the
efficiency, effectiveness and sustainability of self-adaptive service
composition. We evaluate DATESSO on a service-based system with real-world
WS-DREAM dataset and comparing it with other state-of-the-art approaches. The
results demonstrate the superiority of DATESSO over the others on the
utilization, latency and running time whilst likely to be more sustainable.Comment: Accepted to the SEAMS '20. Please use the following citation: Satish
Kumar, Tao Chen, Rami Bahsoon, and Rajkumar Buyya. DATESSO: Self-Adapting
Service Composition with Debt-Aware Two Levels Constraint Reasoning. In
IEEE/ACM 15th International Symposium on Software Engineering for Adaptive
and Self-Managing Systems, Oct 7-8, 2020, Seoul, Kore
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