BPEL'n'Aspects: Adapting Service Orchestration Logic

Abstract

The need for flexibility in process-based applications, in particular during their execution, places the demand for enabling adaptability of processes. AOP is considered to be one of the approaches to flexibly switch on and off functionality on per-instance basis in applications during their execution; analogously, this paradigm can be applied in a BPEL environment to enable adaptation of running orchestrations. In the presented approach we strive towards reuse of as much concepts and technology already available in a Web service (WS) environment as possible.We combine standard BPEL, the publish/subscribe paradigm and WS-Policy so that WS operations play the role of aspects with respect to BPEL processes. We present the syntax for such aspects as an extension of the WS-Policy framework. We introduce the architecture of the supporting infrastructure and a prototypical implementation. The approach draws on the combined benefits of service orientation and the AOP paradigm to improve the state-of-the-art techniques for flexibility of service orchestrations in a non-intrusive manner.

DSOL: a declarative approach to self-adaptive service orchestrations

“…AO4BPEL [13] and BPEL'n'Aspects [25] are two notable representatives of this class of systems, which are built around an aspect-oriented extension to BPEL. In this section we focus on the former as it addresses both modularity and run-time adaptability as we do with DSOL.…”

Process as a Service Distributed Multi-tenant Policy-Based Process Runtime Governance

“…Central to AOP is weaving, which introduces the advice code at the captured join points of the target program. Regarding BPEL processes, AOP concept has be adopted for BPEL to support dynamic changes of business processes [6], [7].…”

A formalized, taxonomy-driven approach to cross-layer application adaptation

“…Aspects can be hot-deployed to BPEL engines that support the aspect-oriented workflow language AO4BPEL. Karastoyanova et al [Karastoyanova and Leymann 2009] illustrate how the AOP paradigm can be mapped and applied in the BPEL language to enable the adaptation of running orchestrations. The authors do not discuss how to generate appropriate WS-Policy attachments (aspects) for the desired service adaptation.…”