Ella Rabinovich

Analyzing the behavior of event processing applications

Event processing application development is a relatively new discipline that poses challenges when applying state-of-the-art software engineering practices. Specifically, the temporal semantics of event processing requires careful validation of the actual behavior against the expected behavior to avoid temporal fallacies. Event processing application development is typically an evolutional process; modifications and extensions to existing applications are very common, thus continuous validation and verification against the requirements and specifications is often required. While small applications are relatively easy to maintain, modifying and extending larger applications with tens and hundreds of assets may be laborious and error-prone. Part of the contemporary platforms has support for modeling, debugging, and testing event processing applications. However, they typically do not practice advanced methods for application validation for correctness and logical integrity. We introduce a novel approach for analyzing the behavior of event processing applications, utilizing static and dynamic analysis techniques, thus providing an ability to draw observations such as: finding event consequences and provenance, possible termination problems, tracing event impact, application artifacts evaluation and coverage. Formal verification methods are leveraged for advanced logical integrity observations. Combined with the techniques mentioned above, this forms a powerful framework for the verification, validation, and auditing of event processing applications.

Application Generation Framework for Real-Time Complex Event Processing

We propose to develop a framework which provides the ability to apply complex event processing in realtime domains, thus allowing an easier process of developing and maintaining specific solutions for real-time event-based systems, while upholding the real time requirements of the system. Specifically, we propose to develop a framework that includes an integrated development environment for defining rules, and, given a set of rules, generates code for a complex event processing application for which it is able to determine time bounds on the response of this application to a set of supported events. In particular, the tool helps determine a time bound for the execution time of the code corresponding to each rule. Many Service Oriented Architecture (SOA) applications, in domains such as financial services, manufacturing, gaming and military/aerospace, have real-time performance requirements. We present real-life industry use cases from these domains as motivation for the potential benefit in developing real-time complex event processing applications. In support of a feasibility argument for the proposed approach we present some preliminary experimental results obtained on a partially implemented tool.

Industry experience with the IBM Active Middleware Technology (AMiT) Complex Event Processing engine

Complex event processing (CEP) is the analysis of event data in real-time to generate immediate insight and enable instant response to changing conditions. In this paper we share the experience we accumulated over the last decade in designing and deploying CEP applications using the IBM Active Middleware Technology (AMiT) CEP engine, a research asset developed at IBM Research - Haifa. Over the years we applied the technology in solutions for various industries, such as banking, insurance, healthcare, chemical and petroleum and more. In each scenario, the CEP engine was used to address different functional requirements including event-based routing, observation, monitoring and correlation. It was also often required to meet nonfunctional requirements such as scalability and transactional support. We describe several solutions from different domains in which AMiT played at least one of these functional or nonfunctional roles. Our experience shows that across the different industries and applications, using the CEP technology, independent of a specific engine implementation, has been consistently proven to be highly successful. It has played a vital role in designing the applications by providing a means to expressively and flexibly define and maintain the event processing logic of the application, and in runtime by being able to meet all the functional and non-functional requirements without taking a toll on the application performance.

On the Retrieval of Wikipedia Articles Containing Claims on Controversial Topics

This work presents a novel claim-oriented document retrieval task. For a given controversial topic, relevant articles containing claims that support or contest the topic are retrieved from a Wikipedia corpus. For that, a two-step retrieval approach is proposed. At the first step, an initial pool of articles that are relevant to the topic are retrieved using state-of-the-art retrieval methods. At the second step, articles in the initial pool are re-ranked according to their potential to contain as many relevant claims as possible using several claim discovery features. Hence, the second step aims at maximizing the overall claim recall of the retrieval system. Using a recently published claims benchmark, the proposed retrieval approach is demonstrated to provide more relevant claims compared to several other retrieval alternatives.

Context-Based Event Processing Systems

The concept of context has recently emerged as one of the major abstractions in event processing modeling with presence in event processing products. In this chapter we discuss the notion of context as a first class citizen within event processing modeling, and discuss its implementation in event processing products and models that arise from the current state-of-the practice

Context aware computing and its utilization in event-based systems

Recently, the notion of context aware computing has attracted attention in various domains, and was mentioned as emerging direction in Gartners 2009 hype cycle for enterprise architecture. The paper provides a brief report of a tutorial given in DEBS 2010 that discusses the notion of context, generally in computing, in event processing modeling, giving examples from the current state-of-the-practice that supports some types of context, but still do not view it as a first class citizen in the model.

A Probabilistic Fusion Framework

There are numerous methods for fusing document lists retrieved from the same corpus in response to a query. Many of these methods are based on seemingly unrelated techniques and heuristics. Herein we present a probabilistic framework for the fusion task. The framework provides a formal basis for deriving and explaining many fusion approaches and the connections between them. Instantiating the framework using various estimates yields novel fusion methods, some of which significantly outperform state-of-the-art approaches.

Generating real-time complex event-processing applications

We propose to exploit the technology for complex event processing (CEP) embodied in the rule-based engine known as IBM Active Middleware Technology™ and extend it to the development of real-time CEP applications. Specifically, we propose to develop a framework that includes an integrated development environment (IDE) for defining rules, and, given a set of rules, generates code for a CEP application and enables us to determine time bounds on the response of this application to a set of supported events. In particular, the IDE helps determine a time bound for the execution time of the code corresponding to each rule. The calculation of time bounds is based on a set of benchmark measurements to be performed on the target hardware and involves code segments corresponding to basic operations. Although we assume the code generation phase produces Java™ code, the same approach can be applied to any other suitable programming language. In support of a feasibility argument for the proposed approach, we present some preliminary experimental results obtained on a partially implemented tool.

Non functional properties of event porcessing

An important aspect of any system is the non-functional aspect, which is not concerned with what a system does, but rather with how well a system works. Since event processing applications are not monolithic, there are various considerations which vary among these applications. In this tutorial we survey the various non-functional properties of event processing systems that in general relate to scalability and performance, availability, correctness and security. The tutorial is presented along three aspects for each topic: requirements, mapping of requirements to event processing application type and current state-of-the-art and research efforts to cope with the various requirements