- BPEL Conformance in Open Source Engines (2012)
- More than five years have passed since the final release of the long-desired OASIS standard of a process language for Web Services orchestration, the Web Services Business Process Execution Language (BPEL). The aim of this standard was to establish a universally accepted Web Services orchestration language that forms a core part of service-oriented architectures and, because of standardization, avoids vendor lock-in. By now, several fully conformant engines should have arrived in the market. It is our aim to shed light on this situation and to provide a comprehensive picture of the current state of BPEL upport. We present an evaluation of the standard conformance of five open source BPEL engines. To obtain these results we have developed betsy, a tool that allows for a fully-automatic standard conformance testing of BPEL engines. The results demonstrate that full standard conformance in contemporary engines is still far from given.
- Measuring the Installability of Service Orchestrations Using the SQuaRE Method (2013)
- Service-oriented software consists of middleware, such as application servers and runtime engines, into which service applications are deployed. This middleware is often complex and difficult to install. The deployment of services requires the crafting of deployment descriptors and packaging of applications. As a consequence, the installation of service-oriented software systems can be a daunting task. Installability, however, is an important influencer of the portability of software. Portability in turn is one of the main goals of service orchestration languages based on open standards. In this paper, we investigate the installability of service orchestrations based on the Systems and software Quality Requirements and Evaluation (SQuaRE) method, the new series of software qual- ity standards currently under development by the ISO/IEC. We develop a measurement framework based on SQuaRE and tailored to evaluating the installability of service orchestrations and their runtimes. We validate the measurement framework theoretically and show its applicability in a case study.
- A Model-Driven Approach for Monitoring ebBP BusinessTransactions ; ( 2nd Place in the IEEE 2011 Services Cup Competition) (2011)
- Towards Standard Conformant BPEL Engines : The Case of Static Analysis (2014)
- The errors in BPEL processes that are only detected at runtime are expensive to fix. Several modelers and process engines for BPEL exist, and the standard defines basic static analysis (SA) rules as a detection mechanism for invalid processes, but the actual conformance of BPEL modelers and engines regarding these rules is unknown. We propose to develop test cases to evaluate the conformance of BPEL modelers and engines regarding static analysis. The evaluation results enable decision makers to identify and use the most conformant engine and modeler that detect errors before runtime and therefore reduce costs
- Open Source versus Proprietary Software in Service-Orientation : The Case of BPEL Engines (2013)
- It is a long-standing debate, whether software that is developed as open source is generally of higher quality than proprietary software. Although the open source community has grown immensely during the last decade, there is still no clear answer. Service-oriented software and middleware tends to rely on highly complex and interrelated standards and frameworks. Thus, it is questionable if small and loosely coupled teams, as typical in open source software development, can compete with major vendors. Here, we focus on a central part of service-oriented software systems, i.e., process engines for service orchestration, and compare open source and proprietary solutions. We use the Web Services Business Process Execution Language (BPEL) and compare standard conformance and its impact on language expressiveness in terms of workflow pattern support of eight engines. The results show that, although the top open source engines are on par with their proprietary counterparts, in general proprietary engines perform better.
- Performance Benchmarking of BPEL Engines: A Comparison Framework, Status Quo Evaluation and Challenges (2014)
- Automated and Isolated Tests for Complex Middleware Products : The Case of BPEL Engines (2014)
- Today, a plethora of enterprise middleware solutions are available, leading to the problem of choosing the right tool for a specific use case. Automated tests can support the selection of such software by determining decision relevant metrics, like e.g., throughput or the degree of standard conformance. To avoid side effects between tests, test isolation, i.e., to provide fresh instances of the software for each test execution, is essential. However, middleware suites are inherently complex, provide a large range of configuration options, have tedious or sometimes manual installation procedures, and long startup times. These idiosyncrasies aggravate the creation of fresh instances of such middleware suites, leading to slower turnaround times and increasing the cost for ensuring test isolation. We aim to overcome these issues with methods and tools from the area of virtualization and devops. In this work, we focus on BPEL engines which are common middleware components in Web Service based SOAs. We applied our proposed method to the BPEL Engine Test System (betsy), a conformance test suite and testing tool for BPEL engines. Results reveal that our method a) enables automatic creation of fresh instances of software without manual installation steps, b) reduces the time to create these fresh instance dramatically, and c) introduces only a neglectable performance overhead, therefore, reducing the overall costs of testing complex software.
- Process Engine Selection Support (2014)
- Nowadays, business processes and their execution are corner stones in modern IT landscapes, as multiple process languages and corresponding engines for these languages have emerged. In practice, it is not feasible to select the best fitting engine, as engine capabilities are mostly hidden in the engine implementation and a comparison is hampered by the large differences and high adoption costs of the engines. We aim to overcome these problems by a) introducing an abstract layer to access the functionality of the engines uniformly, b) by revealing the engine capabilities through automated and isolated tests for typical requirements, and c) support the user in their selection of a process engine by determining and explaining the fitness of the engines for a single process or a given set of processes using policy matching against previously revealed engine capabilities. Early results show the general feasibility of our approach for BPEL engines for a single capability. Keywords: BPM, process engines, engine selection, execution requirements, testing
- Towards Uniform BPEL Engine Management in the Cloud (2014)
- The Web Services Business Process Execution language (BPEL) is a standard for modeling and executing automated processes and is tailor-made for service orchestration. BPEL specifies a serialization format which every BPEL implementation has to understand, thus allowing for the portability of processes among runtime engines. Although the modeling and execution of BPEL processes is portable between engines to a large degree, the lifecycle management of BPEL processes is not standardized and varies a lot for different engines. This paper presents a first approach for a uniform and cloud-based lifecycle management of BPEL processes and engines. We infer a uniform interface for the lifecycle management from the capabilities of current engines and provide a prototypic implementation of a tool that manages processes and engines on a TOSCA-compliant infrastructure.
- QoS-Enabled B2B Integration (2009)
- Business-To-Business Integration (B2Bi) is a key mechanism for enterprises to gain competitive advantage. However, developing B2Bi applications is far from trivial. Inter alia, agreement among integration partners about the business documents and the control flow of business document exchanges as well as applying suitable communication technologies for overcoming heterogeneous IT landscapes are major challenges. At the same time, choreography languages such as ebXML BPSS (ebBP), orchestration languages such as WS-BPEL and Web Services are promising to provide the foundations for seamless interactions among business partners. Automatically translating choreography agreements of integration partners into partner-specific orchestrations is an obvious idea for ensuring conformance of orchestration models to choreography models. Moreover, the application of such model-driven development methods facilitates productivity and cost-effectiveness whereas applying a service oriented architecture (SOA) based on WS-BPEL and Web Services leverages standardization and decoupling. By now, the realization of QoS attributes has not yet received the necessary attention that makes such approaches suitable for B2Bi. In this report, we describe a proof-of-concept implementation of the translation of ebBP choreographies into WS-BPEL orchestrations that respects B2Bi-relevant QoS attributes.