Ubiquitous Nature of Event-Driven Approaches: A Retrospective View

This paper retrospectively analyzes the progress of event-based capability and their applicability in various domains. Although research on event-based approaches started in a humble manner with the intention of introducing triggers in database management systems for monitoring application state and to automate applications by reducing/eliminating user intervention, currently it has become a force to reckon with as it finds use in many diverse domains. This is primarily due to the fact that a large number of real-world applications are indeed event-driven and hence the paradigm is apposite. In this paper, we briefly overview the development of the ECA (or event-condition-action) paradigm. We briefly discuss the evolution of the ECA paradigm (or active capability) in relational and Object-oriented systems. We then describe several diverse applications where the ECA paradigm has been used effectively. The applications range from customized monitoring of web pages to specification and enforcement of access control policies using RBAC (role-based access control). The multitude of applications clearly demonstrate the ubiquitous nature of event-based approaches to problems that were not envisioned as the ones where the active capability would be applicable. Finally, we indicate some future trends that can benefit from the ECA paradigm

A Rule-Based Language for Integrating Business Processes and Business Rules

International audienceBusiness process modeling has become a popular method for improving organizational efficiency and quality. Automatic validation of process models is one of the most valuable features of modeling tools, in face of the increasing complexity of enterprise business processes and the richness of modeling languages. This paper proposes a formal language, Event-Condition-Action-Event (ECAE), for integrating Colored Petri Nets (CPN)-based business process with a set of business rules. We automate the integration process for validating the business process model. The ECAE language has several important features: its reasoning capabilities, its ability to express complex actions and events, and its declarative semantics. By enabling simulation of business process behavior, the reasoning capabilities facilitate the early detection of flaws The widespread use of business process modeling has helped enterprises to design, control and analyze many operational processes. Unfortunately, syntactic and semantic inconsistencies often appear in business process models, especially as the complexity of the models increases. Flaw detection and automation are essential for ensuring cost-effective and correct process models. The challenge for system designers is to build a flexible intelligent system, which accepts and verifies the change on business process and business rules automatically. The business process must be integrated with a set of business rules, and a correspondence between the process and the rules must be created. This must be flexible since the business process and the business rules may be modified during runtime. The verification should be a rule-based system, which can reason and deduce new knowledge or a new decision based on a set of rules and facts. This paper proposes a formal language ECAE for business process modeling, which takes advantage of both the graphical representation of colored Petri nets and the easy to represent ECA rule. It designs a business process model through CPN and translate

Entwurf eines Frameworks für komplexe Events auf verteilten, reaktiven Datenbanken und Triple-Stores

Diese Arbeit stellt ein Framework für komplexe Events auf Grundlage von Event-Condition-Action-Rules für verteilte Datenquellen vor. Dabei soll die Definition von atomaren und komplexen Events, dezentral über eine administrative Applikation, möglich sein. Zur Ausführung von Aktionen jeglicher Art, als Reaktion auf ein eingetretenes Ereignis, kann auf die Funktionalität von SOAP-Endpunkten zurückgegriffen werden. Durch die Präsentation einer einfachen, aktiven Hülle für passive Triple-Stores einer Virtuoso-Datenbank soll eine Möglichkeit zur Schaffung reaktiver Triple-Stores demonstriert werden

The Language XChange

The research topic investigated by this thesis is reactivity on the Web. Reactivity on the Web is an emerging research issue covering: updating data on the Web, exchanging information about events (such as executed updates) between Web sites, and reacting to combinations of such events. Following a declarative approach to reactivity on the Web, a novel reactive language called XChange is proposed. Novelties of the language are represented by the proposed data metaphor intended to ease the language understanding and the supported reactive features tailored to the characteristics of the Web. Realising this pressuposed refining, extending, and adapting to a new medium some of the concepts on which active database systems are built upon. Reactivity is specified in XChange by means of reactive rules (or event-condition-action rules) having the following components: the event part is a query against events that occurred on the Web, the condition part is a query against Web resources (expressed in the Web query language Xcerpt), and the action part is a transaction specification (specifying updates to be executed and events to be raised in an all-or-nothing manner). Novel in XChange is its ability to detect composite events on the Web, i.e. possibly time related combinations of events that have occurred at (same or different) Web sites. XChange introduces a novel view over the Web data by stressing a clear separation between persistent data (data of Web resources, such as XML or HTML documents) and volatile data (event data communicated on the Web between XChange programs). Based on the differences between these kinds of data, the data metaphor is that of written text vs. speech. XChange's language design enforces this clear separation and entails new characteristics of event processing on the Web. After motivating the need for a solution to reactivity on the Web, this thesis introduces the design principles and syntax of the language XChange accompanied by use cases for demonstrating the practical applicability of its constructs. Important contributions of the thesis are the specification of the language semantics and the description of an algortihm for evaluating XChange programs

Knowledge-base and techniques for effective service-oriented programming & management of hybrid processes

Recent advances in Web 2.0, SOA, crowd-sourcing, social and collaboration technologies, as well as cloud-computing, have truly transformed the Internet into a global development and deployment platform. As a result, developers have been presented with ubiquitous access to countless Web-services, resources and tools. However, while enabling tremendous automation and reuse opportunities, new productivity challenges have also emerged: The exploitation of services and resources nonetheless requires skilled programmers and a development-centric approach; it is thus inevitably susceptible to the same repetitive, error-prone and time consuming integration work each time a developer integrates a new API. Business Process Management on the other hand were proposed to support service-based integration. It provided the benefit of automation and modelling, which appealed to non-technical domain-experts. The problem however: it proves too rigid for unstructured processes. Thus, without this level of support, building new application either requires extensive manual programming or resorting to homebrew solutions. Alternatively, with the proliferation of SaaS, various such tools could be used for independent portions of the overall process - although this either presupposes conforming to the in-built process, or results in "shadow processes" via use of e-mail or the like, in order to exchange information and share decisions. There has therefore been an inevitable gap in technological support between structured and unstructured processes. To address these challenges, this thesis deals with transitioning process-support from structured to unstructured. We have been motivated to harness the foundational capabilities of BPM for its application to unstructured processes. We propose to achieve this by: First, addressing the productivity challenges of Web-services integration - simplifying this process - whilst encouraging an incremental curation and collective reuse approach. We then extend this to propose an innovative Hybrid-Process Management Platform that holistically combines structured, semi-structured and unstructured activities, based on a unified task-model that encapsulates a spectrum of process specificity. We have thus aimed to bridge the current lacking technology gap. The approach presented has been exposed as service-based libraries and tools. Whereby, we have devised several use-case scenarios and conducted user-studies in order to evaluate the overall effectiveness of our proposed work

An event-condition-action language for RDF

RDF is becoming a core technology in the Semantic Web. Providing the ability to describe metadata information that can be easily navigated, and the ease of storing it in existing relational database systems, have made RDF a very popular way of expressing and exchanging metadata information. However, the use of RDF in dynamic applications over distributed environments that require timely notification of metadata changes raises the need for mechanisms for monitoring and processing such a changes. Event-ConditionAction (ECA) rules are a natural candidate to fulfill this need. In this paper, we study ECA rules in the context of RDF metadata. We give a detailed description of a language to define ECA rules on RDF repositories. We specify the syntax and semantics of the language, and we illustrate its use by examples. We also describe the architecture of a system implementing this language, both for centralised and distributed environments

RDFTL: An Event-Condition-Action Language for RDF

RDF is becoming a core technology in the Semantic Web. Providing the ability to describe metadata information that can be easily navigated, and the ease of storing it in existing relational database systems, have made RDF a very popular way of expressing and exchanging metadata information. However, the use of RDF in dynamic applications over distributed environments that require timely notification of metadata changes raises the need for mechanisms for monitoring and processing such a changes. Event-Condition-Action (ECA) rules are a natural candidate to fulfill this need. In this paper, we study ECA rules in the context of RDF metadata. We give a detailed description of a language to define ECA rules on RDF repositories. We specify the syntax and semantics of the language, and we illustrate its use by examples.