Optimizing Expressibility and Performance of Kleene Operators on Binary Tree-based Directed Graph in Complex Event Processing

Complex event processing (CEP) systems have gained significant importance in various domains, such as finance, logistics, and security, where the real-time analysis of event streams is crucial. However, as the volume and complexity of event data continue to grow, optimizing the performance of CEP systems becomes a critical challenge. This paper investigates the impact of indexing strategies on the performance of databases handling complex event processing. We propose a novel indexing technique, called Hierarchical Temporal Indexing (HTI), specifically designed for the efficient processing of complex event queries. HTI leverages the temporal nature of event data and employs a multi-level indexing approach to optimize query execution. By combining temporal indexing with spatial- and attribute-based indexing, HTI aims to accelerate the retrieval and processing of relevant events, thereby improving overall query performance. In this study, we evaluate the effectiveness of HTI by implementing complex event queries on various CEP systems with different indexing strategies. We conduct a comprehensive performance analysis, measuring the query execution times and resource utilization (CPU, memory, etc.), and analyzing the execution plans and query optimization techniques employed by each system. Our experimental results demonstrate that the proposed HTI indexing strategy outperforms traditional indexing approaches, particularly for complex event queries involving temporal constraints and multi-dimensional event attributes. We provide insights into the strengths and weaknesses of each indexing strategy, identifying the factors that influence performance, such as data volume, query complexity, and event characteristics. Furthermore, we discuss the implications of our findings for the design and optimization of CEP systems, offering recommendations for indexing strategy selection based on the specific requirements and workload characteristics. Finally, we outline the potential limitations of our study and suggest future research directions in this domain.

Goal of Complex Event Processing (CEP) is to identify meaningful events (such as opportunities or threats) and respond to them as quickly as possible. Traditional CEP frameworks do not have built-in security features. Any intruder may enter into the system and may send incorrect data to CEP engine. It causes to miss some patterns or it may lead to wrong prediction of patterns. Traditional CEP systems can be exploited through one or the other way. CEP system malfunctions when it is exploited. There is no built in procedure to check the health status of traditional CEP systems. Traditional CEP systems do not have procedures to take appropriate actions when system is affected or going to affect. When CEP system identifies some patterns, it will alert corresponding personnel about the occurrence of the event. Sometimes alert message may be undelivered or unnoticed by the corresponding people. Traditional CEP systems will not provide delivery assurance of alert message. These are few security challenges to existing CEP systems. In this paper Secure Complex Event Processing Framework is proposed to address above security challenges. Proposed framework is generic and it is pluggable into any existing CEP systems.

The nature of data in enterprises and on the Internet is changing. Data used to be stored in a database first and queried later. Today timely processing of new data, represented as events, is increasingly valuable. In many domains, complex event processing (CEP) systems detect patterns of events for decision making. Examples include processing of environmental sensor data, trades in financial markets and RSS web feeds. Unlike conventional database systems, most current CEP systems pay little attention to query optimisation. They do not rewrite queries to more efficient representations or make decisions about operator distribution, limiting their overall scalability. This paper describes the Next CEP system that was especially designed for query rewriting and distribution. Event patterns are specified in a high-level query language and, before being translated into event automata, are rewritten in a more efficient form. Automata are then distributed across a cluster of machines for detection scalability. We present algorithms for query rewriting and distributed placement. Our experiments on the Emulab test-bed show a significant improvement in system scalability due to rewriting and distribution. 1.

SUMMARYRecently, event processing (EP) has gained considerable attention as an individual discipline in computer science. From a software engineering perspective, EP systems still lack the maturity of well‐established software architectures. For the development of industrial EP systems, generally accepted software architectures based on proven design patterns and principles are still missing. In this article, we introduce a catalog of design patterns that supports the development of event‐driven architectures (EDAs) and complex EP systems. The design principles originate from experiences reported in publications as well as from our own experiences in building EP systems with industrial and academic partners. We present several patterns on different layers of abstractions that define the overall structure as well as the building blocks for EP systems. Architectural patterns that determine the top‐level structure of an EDA can be distinguished from design patterns that specify the basic mechanisms of EP. The practical application of the catalog of patterns is described by the pattern‐based design of a sample EDA for a sensor‐based energy control system. Finally, we propose a coherent and general reference architecture for EP derived from the proposed patterns.Copyright © 2013 John Wiley & Sons, Ltd.

In such areas as transport, healthcare, business process management, financial services, complex event processing (CEP) systems are becoming in demand. Large volumes of streams of events are generated and collected by these systems. Real-time processing of event stream data is essential. Based on current and past events, a decision is made, and forecasting future events is an alternative goal. For the fastest reaction to non-standard behavior, it is necessary to process data streams in real time, it means, as quickly as possible. That's why it is important to find new technologies which can speed up data processing. In this article expensive queries in CEP is identified, effective optimizations to improve their performance significantly is proposed. It is developed and implemented algorithm, which should decrease processing time. The results are compared with state-of-the-art CEP system.

We present in this paper logical tools for verification of Complex Event Processing (CEP) system at design time, and maintenance at runtime. Although the framework is general enough for most applications, we focus on its use in Business Process Management (BPM).

The use of Complex Event Processing (CEP) and Stream Processing (SP) systems to process high-volume, high-velocity Big Data has renewed interest in procedures for managing these systems. In particular, self-management and adaptation of runtime platforms have been common research themes, as most of these systems run under dynamic conditions. Nevertheless, the research landscape in this area is still young and fragmented. Most research is performed in the context of specific systems, and it is difficult to generalize the results obtained to other contexts. To enable generic and reusable CEP/SP system management procedures and self-management policies, this research introduces the Attributed Graph Rewriting for Complex Event Processing Management ( AGeCEP ) formalism. AGeCEP represents queries in a language- and technology-agnostic fashion using attributed graphs. Query reconfiguration capabilities are expressed through standardized attributes, which are defined based on a novel classification of CEP query operators. By leveraging this representation, AGeCEP also proposes graph rewriting rules to define consistent reconfigurations of queries. To demonstrate AGeCEP feasibility, this research has used it to design an autonomic manager and to define a selected set of self-management policies. Finally, experiments demonstrate that AGeCEP can indeed be used to develop algorithms that can be integrated into diverse CEP systems.

Complex event processing has become an important technology for big data and intelligent computing because it facilitates the creation of actionable, situational knowledge from potentially large amount events in soft realtime. Complex event processing can be instrumental for many mission-critical applications, such as business intelligence, algorithmic stock trading, and intrusion detection. Hence, the servers that carry out complex event processing must be made trustworthy. In this paper, we present a threat analysis on complex event processing systems and describe a set of mechanisms that can be used to control various threats. By exploiting the application semantics for typical event processing operations, we are able to design lightweight mechanisms that incur minimum runtime overhead appropriate for soft realtime computing.

Complex Event Processing (CEP) systems aim at processing large flows of events to discover situations of interest. In CEP, the processing takes place according to user-defined rules, which specify the (causal) relations between the observed events and the phenomena to be detected. We claim that the complexity of writing such rules is a limiting factor for the diffusion of CEP. In this paper, we tackle this problem by introducing iCEP, a novel framework that learns, from historical traces, the hidden causality between the received events and the situations to detect, and uses them to automatically generate CEP rules. The paper introduces three main contributions. It provides a precise definition for the problem of automated CEP rules generation. It dicusses a general approach to this research challenge that builds on three fundamental pillars: decomposition into subproblems, modularity of solutions, and ad-hoc learning algorithms. It provides a concrete implementation of this approach, the iCEP framework, and evaluates its precision in a broad range of situations, using both synthetic benchmarks and real traces from a traffic monitoring scenario.

With the increasing adoption of an event-based perspective in many organizations, the demands for automatic processing of events are becoming more sophisticated. Although complex event processing systems can process events in near real-time, these systems rely heavily upon human domain experts. This becomes an issue in application areas that are rich in specialized domain knowledge and background information, such as clinical environments. We utilize a framework of four techniques to enhance complex event processing with domain knowledge from ontologies to address this issue. We realize this framework in our novel approach of ontology-supported complex event processing, which stands in contrast to related approaches and emphasizes the strengths of current advances in the individual fields of complex event processing and ontologies. Experimental results from the implementation of our approach based on a state-of-the-art system show its feasibility and indicate the direction for future research.

Complex Event Processing (CEP) systems extract interest situations from event flows based on event detection patterns. However, local event processing for distributed Internet of Things (IoT) has not been discussed yet. Besides, it is complex or impossible to discover such patterns in some applications of IoT. In this article, we design a complex event service to process event flows based on IoT resource models, which does not depend on existing patterns, and deals with both discrete events and continuous variables. To improve the CEP performance, local IoT resources are used for local event processing, and a lazy exchange method is designed to realize the collaborated event processing between network edges and a data center. Our evaluation shows that our solution is feasible and effective.

Complex event processing (CEP) over event streams has become increasingly important for real-time applications ranging from health care, supply chain management to business intelligence. These monitoring applications submit complex event queries to track sequences of events that match a given pattern. As these systems mature the need for increasingly complex nested sequence query support arises, while the state-of-art CEP systems mostly support the execution of only flat sequence queries. In this paper, we introduce our nested CEP query language NEEL for expressing nested queries composed of sequence, negation, AND and OR operators. Thereafter, we also define its formal semantics. Subtle issues with negation and predicates within the nested sequence context are discussed. An E-Analytics system for processing nested CEP queries expressed in the NEEL language has been developed. Lastly, we demonstrate the utility of this technology by describing a case study of applying this technology to a real-world application in health care.

Complex event processing is a key technology for analyzing event patterns in real-time data streams. It has been widely applied in IoT monitoring, financial risk control, smart manufacturing and other time-sensitive fields. Query patterns serve as the core matching mechanism in complex event processing systems. These patterns are primarily defined through selection policies, predicate constraints and timestamps to establish complex event detection rules. The selection policy is particularly important as it determines the sequential relationships between events. This directly affects the system's event matching efficiency and accuracy. However, in practical applications, due to different business requirements for event sampling frequencies, event streams often contain numerous consecutive events of the same type representing identical states. While all these events participate in complex event matching, traditional processing methods generate large numbers of semantically redundant partial matches. Analysis shows that only a very small proportion of these intermediate results eventually form complete matches, creating serious computational redundancy issues. This redundancy not only significantly increases system resource consumption but also reduces overall processing efficiency due to ineffective computations. To address this critical problem, this paper innovatively proposes a cache-based optimized selection policy. The core concept of this policy is to effectively reduce redundant matching results by extracting representative events from continuous event sequences. Experimental results show that this policy can significantly decrease the redundant matching rate while alleviating system load, providing new insights for optimizing complex event processing systems.

This paper describes a scalable complex event processing (CEP) system and rule allocation algorithm for large-scale M2M services and presents the results of its performance evaluations. Platforms providing M2M services deal with various data from massive event sources in the real world. To realize these services, a scalable system is required. Our previous system determines efficient allocation of CEP rules based on a single key attribute type. However, it cannot maintain scalability in M2M situation because CEP rules are defined by various attribute types and there is no single key attribute, i.e. common attribute type among CEP rules. The challenging issue in the present work is how to maintain scalability where no common attribute type usable for rule allocation. The key idea in this paper is to allocate CEP rules based on different attribute types for each CEP rule instead of single key attribute type. We propose a rule allocation algorithm that determines the efficient allocation of CEP rules when the system needs processing a large number of events, a large number of CEP rules, and various types of events. Evaluation results show that the system with the proposed algorithm is scalable with many CEP Servers. We thus conclude that the proposed algorithm contributes to the realization of large-scale M2M services.

Owing to Big Data popularity, the metrics Variety, Volume and Velocity (V3), are gaining importance in large scale data intensive applications. Complex Event Processing (CEP) is an efficient solution for identifying events of interest on data streams arriving from geographically distributed heterogeneous sources in near-real time. CEP is capable of handling large variety of data with high computational velocity and delivers better solution compared to other existing techniques. However, handling large volume data streams still poses challenge in CEP systems. Hence, a middleware is required to manage huge streams of data on scalable distributed environment. This paper proposes Scalable Complex Event Processing (SCALACEP) framework for managing voluminous data streams. This paper addresses challenges such as state management and efficient rule distribution for design of distributed framework for CEP using the proposed SCALACEP. This paper also proposes a novel way of indexing CEP rules based on Geometric series. The proposed indexing is used for CEP Rule allocation and CEP rule pruning in the SCALACEP system. SCALACEP is evaluated and compared with other existing systems in the constrained virtualized environment and found to give better results in terms of throughput and reduction in Latency and Multicast.