Resource Optimization for Web Service Composition (original) (raw)

Efficient QoS-aware Service Composition

Emerging Web Services Technology Volume III, 2010

Web service composition requests are usually combined with end-toend QoS requirements, which are specified in terms of non-functional properties (e.g. response time, throughput and price). The goal of QoS-aware service composition is to find the best combination of services such that their aggregated QoS values meet these end-to-end requirements. Local selection techniques are very efficient but fail short in handling global QoS constraints. Global optimization techniques, on the other hand, can handle global constraints, but their poor performance render them inappropriate for applications with dynamic and realtime requirements. In this paper we address this problem and propose a solution that combines global optimization with local selection techniques for achieving a better performance. The proposed solution consists of two steps: first we use mixed integer linear programming (MILP) to find the optimal decomposition of global QoS constraints into local constraints. Second, we use local search to find the best web services that satisfy these local constraints. Unlike existing MILPbased global planning solutions, the size of the MILP model in our case is much smaller and independent on the number of available services, yields faster computation and more scalability. Preliminary experiments have been conducted to evaluate the performance of the proposed solution.

A Survey of QoS-aware Web Service Composition Techniques

Web service composition can be briefly described as the process of aggregating services with disparate functionalities into a new composite service in order to meet increasingly complex needs of users. Service composition process has been accurate on dealing with services having disparate functionalities, however, over the years the number of web services in particular that exhibit similar functionalities and varying Quality of Service (QoS) has significantly increased. As such, the problem becomes how to select appropriate web services such that the QoS of the resulting composite service is maximized or, in some cases, minimized. This constitutes an NP-hard problem as it is complicated and difficult to solve. In this paper, a discussion of concepts of web service composition and a holistic review of current service composition techniques proposed in literature is presented. Our review spans several publications in the field that can serve as a road map for future research.

Combining global optimization with local selection for efficient QoS-aware service composition

Proceedings of the 18th international conference on World wide web - WWW '09, 2009

The run-time binding of web services has been recently put forward in order to support rapid and dynamic web service compositions. With the growing number of alternative web services that provide the same functionality but differ in quality parameters, the service composition becomes a decision problem on which component services should be selected such that user's end-to-end QoS requirements (e.g. availability, response time) and preferences (e.g. price) are satisfied. Although very efficient, local selection strategy fails short in handling global QoS requirements. Solutions based on global optimization, on the other hand, can handle global constraints, but their poor performance renders them inappropriate for applications with dynamic and realtime requirements. In this paper we address this problem and propose a solution that combines global optimization with local selection techniques to benefit from the advantages of both worlds. The proposed solution consists of two steps: first, we use mixed integer programming (MIP) to find the optimal decomposition of global QoS constraints into local constraints. Second, we use distributed local selection to find the best web services that satisfy these local constraints. The results of experimental evaluation indicate that our approach significantly outperforms existing solutions in terms of computation time while achieving close-tooptimal results.

Efficient anytime algorithm for large-scale QoS-aware web service composition

International Journal of Web and Grid Services, 2013

The QoS-aware web service composition (WSC) problem aims at the fully automatic construction of a composite web service with the optimal accumulated QoS value. It is, however, intractable to solve the QoS-aware WSC problem for large scale instances since the problem corresponds to a global optimisation problem. That is, in the real world, traditional algorithms can require significant amount of time to finally find the optimal solution, and such an unexpected long delay is unfavourable to users. In this paper, we propose a novel anytime algorithm using dynamic beam widths for the QoSaware WSC problem. Our algorithm generates early sub-optimal solutions and keeps improving the quality of the solution along with the execution time, up to the optimal solution if a client allows enough time. We empirically validate that our algorithm can identify composite web services with high quality much earlier than an optimal algorithm and the beam stack search.

A Community Based Algorithm for Large Scale Web Service Composition

Web service composition is the process of synthesizing a new composite service using a set of available Web services in order to satisfy a client request that cannot be treated by any available Web services. The Web services space is a dynamic environment characterized by a huge number of elements. Furthermore, many Web services are offering similar functionalities. In this paper we propose a model for Web service composition designed to address the scale effect and the redundancy issue. The Web services space is represented by a two-layered network architecture. A concrete similarity network layer organizes the Web services operations into communities of functionally similar operations. An abstract interaction network layer represents the composition relationships between the sets of communities. Composition synthesis is performed by a two-phased graph search algorithm. First, the interaction network is mined in order to discover abstract solutions to the request goal. Then, the abstract compositions are instantiated with concrete operations selected from the similarity network. This strategy allows an efficient exploration of the Web services space. Furthermore, operations grouped in a community can be easily substituted if necessary during the composition's synthesis's process.

A Graph based meta-model for speed-up service composition on web

2014 IEEE International Conference on Industrial Technology (ICIT), 2014

Service composition is one of the key issues in web engineering to satisfy users query on the fly. The efficient composition technique demands low execution time. Moreover, the approach should include the fast delivery of an alternative plan in case of failure in run-time. Most of the existing techniques are unable to deliver any result in case of partial matching with the requirement of the user. In this paper, we have proposed a meta-model in terms of a Graph to work on the above said issues. The Graph that contains information required for composition is prepared offline and is used for generating query specific composition plan. The methodology for finding out the specific composition plan, for partial matching also, is illustrated with an example. The solution is expected to behave in an efficient way in terms of providing dynamic service composition techniques.

An Optimal Semantic Network-Based Approach for Web Service Composition with QoS

Jiang Zi-Long Naji Hasan.A.H, Gao Shu, AL-Gabri Malek, 2013

As the spread of web services, the composition of web services becomes a hot topic on both the academia and IT domains. The composition of services depends on the semantic descriptions, which describe the functionality of the services, provided by the owners of services and on the description of the consumer's requests. The composition also depends on nonfunctional descriptions (QoS). In this paper, we present an approach of web services composition based on both semantic description and QoS. The proposed approach builds a network of web services by matchmaking the semantic concepts in OWLS , using the outputsinputs similarity between services. Then, many composed assemblies can be created by combining web services in the semantic network according to consumer's needs. Those composed assemblies will be ranked by the QoS that provided by the consumer and the suitable one will be sent back to the consumer. This approach takes the advantages from Pellete DL

An Algorithm to Select the Optimal Composition of the Services

Because of providing services to the users in the heterogeneous distributed environments, service oriented systems are very important. Most of the time, the individual services do not have the sufficient conditions to provide any services to the users. In order to resolve the aforementioned problem, one may compose several individual services together.

Effective Service Composition Approach based on Pruning Performance Bottlenecks

9th International Conference on Computer Science, Engineering and Applications (CCSEA 2019), 2019

In recent years, several online services have proliferated to provide similar services with same functionality by different service providers with varying Quality of Service (QoS) properties. So, service composition should provide effective adaptation especially in a dynamically changing composition environment. Meanwhile, a large number of component services pose scalability issues. As a result, monitoring and resolving performance problems in web services based systems is challenging task as these systems depend on component web services that are distributed in nature. In this paper, a distributed approach is used to identify performance related problems in component web services. The service composition adaptation provides timely replacement of the performance bottleneck source that can prohibit performance degradation for the forthcoming requests. Experimentation results demonstrate the efficiency of the proposed approach, and also the quality of solution of a service composition is maintained.