Synthesizing the Mediator with jABC/ABC.
Tiziana Margaria · 2008
Abstract. In this paper we show how to apply a tableau-based software com-position technique to automatically generate the mediator’s service logic. Thisuses an LTL planning (or configuration) algorithm originally embedded in theABC and in the ETI platforms. The algorithm works on the basis of the existingjABC library of available services (SIB library) and of an enhanced descriptionof their semantics given in terms of a taxonomic classification of their behaviour(modules) and abstract interfaces/messages (types). 1 The SWS Challenge Mediator The ongoing Sematic Web Service Challenge [19] proposes a number of increasinglycomplexscenariosforworkflow-basedservicemediationandservicediscovery.Weusehere the technology presented in [10] to synthesise a process that realizes the commu-nication layer for the Challenge’s initial mediation scenario.Inthisscenario,acustomer(technically,aclient)initiatesaPurchaseOrderRequestspecifiedbyaspecialmessageformat(RosettaNetPIP3A4)andwaitsforacorrespond-ingPurchaseOrderConfirmationaccordingtothesameRosettaNetstandard.Thesellerhoweverdoesnotsupportthisstandard.Itsbackendsystemorserverawaitsanorderinaproprietary message format and provides appropriate Web Services to serve the requestin the proprietary format. As client and server here speak different languages, there is aneed for a mediation layer that adapts both the data formats and also the granularity.Of course we can easily define the concrete process within our jABC modellingframework, as we have shown in the past [11,6,7].To provide a more flexible solution framework, especially to accommodate laterdeclarative specification changes on the backend side or on the data flow, we synthe-size the whole mediator using the synthesis technology introduced in [10]. We proceedhere exactly along the lines already presented in that paper.In the following, we show in Sect. 2 how to use the SLTL synthesis methodology togeneratethemediatorworkflowbasedonaknowledgebasethatexpressesthesemantics