A rule-based approach for availability of service by automated service substitution

Abstract

SUMMARY High availability of software components has long been studied. For a software system, when unavailability of a component has caused a suspension of the system, the system has to be recovered or resumed as soon as possible. To substitute an unavailable software component with a backup copy is therefore unavoidable in achieving high availability of software systems. In this paper, in comparison with using redundancies, we take an alternative approach that steps away from the physical code equivalence of the software but focuses more on the equivalence in using the function unit without concerning about the implementation itself. We investigate the problem of Web service availability in service‐oriented software systems and then report a framework for Web service availability in such systems using automated and rule‐based Web service substitution. The framework takes a novel approach to manage the runtime replacement of services, combining (i) an approach that classifies services using co‐occurrence of terms in various tags of the service descriptions, (ii) an approach to establish the compatibility and substitution of service operation interfaces and (iii) a middleware for handling service replacements. Our approach is designed to address the problem of Web service availability from the client side and assumes that the client has no control of the Web service providers. This is a completely distributed approach in comparison with other related work and presents a valuable benefit of client orientation. As two additional distinguishing characteristics, our framework also meets the challenges of (i) semantic heterogeneity of Web services in identifying substitute service and (ii) transparency and independence in handling unavailability at the level of Web services. We show in our experiments that the service substitute identification based on the proposed framework achieves a best precision of 85%. We demonstrate our implementation of the middleware for service unavailability handling in the framework. We also present experiments on service substitution within a demo business application in the presence of unavailability. Copyright © 2012 John Wiley & Sons, Ltd.

A Cluster and Process Collaboration-Aware Method to Achieve Service Substitution in Cloud Service Processes

“…By targeting substitutions, the reconfigured web service will better satisfy users' requirements [17]. ree rules are provided to establish the compatibility and substitution of service operation interfaces [18]. e experiments to show service substitute identification based on the proposed framework achieve a best precision of 85%.…”

The influencing causes of software unavailability: A case study from industry

“…The N‐way active redundancy model outperformed the others. Liang et al presented a rule‐based Web service substitute scheme to handle service unavailability. In comparison with using redundancies, they took an alternative approach that steps away from the physical code equivalence of the software but focuses more on the equivalence in using the function unit without concern about the implementation itself.…”

Verifying compositional equivalence between web service composition graphs

“…In case that if a service becomes unavailable from a community, other services from the community could be employed. Liang et al also followed a similar approach of classifying Web services using their descriptions. Motahari‐Nezhad et al advocated that the checking of service equivalence should not be done merely on the basis of interface; its business protocol also must be considered.…”

“…Another interface‐based similarity measurement between services was studied in the work of Tibermacine et al They computed the substitutability on the basis of various interface matching techniques and semantic and structural similarity metrics. We differ from other works() in that we compute the service equivalence on the basis of fulfillment of a given composition request instead of the interface. The overview of major existing approaches for Web service substitutability and differences with our proposed approach are shown in Table .…”