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220
High-performance complex event processing over streams
- In SIGMOD
, 2006
"... In this paper, we present the design, implementation, and evaluation of a system that executes complex event queries over real-time streams of RFID readings encoded as events. These complex event queries filter and correlate events to match specific patterns, and transform the relevant events into n ..."
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Cited by 161 (7 self)
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In this paper, we present the design, implementation, and evaluation of a system that executes complex event queries over real-time streams of RFID readings encoded as events. These complex event queries filter and correlate events to match specific patterns, and transform the relevant events into new composite events for the use of external monitoring applications. Stream-based execution of these queries enables time-critical actions to be taken in environments such as supply chain management, surveillance and facility management, healthcare, etc. We first propose a complex event language that significantly extends existing event languages to meet the needs of a range of RFID-enabled monitoring applications. We then describe a query plan-based approach to efficiently implementing this language. Our approach uses native operators to efficiently handle query-defined sequences, which are a key component of complex event processing, and pipelines such sequences to subsequent operators that are built by leveraging relational techniques. We also develop a large suite of optimization techniques to address challenges such as large sliding windows and intermediate result sizes. We demonstrate the effectiveness of our approach through a detailed performance analysis of our prototype implementation as well as through a comparison to a state-of-the-art stream processor. 1
Efficient pattern matching over event streams
, 2007
"... Pattern matching over event streams is increasingly being employed in many areas including financial services, RFID-based inventory management, click stream analysis, and elec-tronic health systems. While regular expression matching is well studied, pattern matching over streams presents two new cha ..."
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Cited by 91 (3 self)
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Pattern matching over event streams is increasingly being employed in many areas including financial services, RFID-based inventory management, click stream analysis, and elec-tronic health systems. While regular expression matching is well studied, pattern matching over streams presents two new challenges: Languages for pattern matching over streams are significantly richer than languages for regular expression matching. Furthermore, efficient evaluation of these pattern queries over streams requires new algorithms and optimiza-tions: the conventional wisdom for stream query processing (i.e., using selection-join-aggregation) is inadequate. In this paper, we present a formal evaluation model that offers precise semantics for this new class of queries and a query evaluation framework permitting optimizations in a principled way. We further analyze the runtime complex-ity of query evaluation using this model and develop a suite of techniques that improve runtime efficiency by exploiting sharing in storage and processing. Our experimental results provide insights into the various factors on runtime perfor-mance and demonstrate the significant performance gains of our sharing techniques.
Processing flows of information: from data stream to complex event processing
- ACM COMPUTING SURVEYS
, 2011
"... A large number of distributed applications requires continuous and timely processing of information as it flows from the periphery to the center of the system. Examples include intrusion detection systems which analyze network traffic in real-time to identify possible attacks; environmental monitori ..."
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Cited by 67 (11 self)
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A large number of distributed applications requires continuous and timely processing of information as it flows from the periphery to the center of the system. Examples include intrusion detection systems which analyze network traffic in real-time to identify possible attacks; environmental monitoring applications which process raw data coming from sensor networks to identify critical situations; or applications performing online analysis of stock prices to identify trends and forecast future values. Traditional DBMSs, which need to store and index data before processing it, can hardly fulfill the requirements of timeliness coming from such domains. Accordingly, during the last decade, different research communities developed a number of tools, which we collectively call Information flow processing (IFP) systems, to support these scenarios. They differ in their system architecture, data model, rule model, and rule language. In this article, we survey these systems to help researchers, who often come from different backgrounds, in understanding how the various approaches they adopt may complement each other. In particular, we propose a general, unifying model to capture the different aspects of an IFP system and use it to provide a complete and precise classification of the systems and mechanisms proposed so far.
COBEA: A CORBA-Based Event Architecture
- in Proceedings of the 4 rd Conference on Object-Oriented Technologies and Systems, USENIX
, 1998
"... Events are an emerging paradigm for composing applications in an open, heterogeneous distributed world. In Cambridge we have developed scalable event handling based on a publish-register-notify model with event object classes and server-side filtering based on parameter templates. After experience ..."
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Cited by 63 (5 self)
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Events are an emerging paradigm for composing applications in an open, heterogeneous distributed world. In Cambridge we have developed scalable event handling based on a publish-register-notify model with event object classes and server-side filtering based on parameter templates. After experience in using this approach in a home-built RPC system we have extended CORBA, an open standard for distributed object computing, to handle events in this way. In this paper, we present the design of COBEA - a COrba-Based Event Architecture. A service that is the source of (parameterised) events publishes in a Trader the events it is prepared to notify, along with its normal interface specification. For scalability, a client must register interest (by invoking a register method with appropriate parameters or wild cards) at the service, at which point an access control check is carried out. Subsequently, whenever a matching event occurs, the client is notified. We outline the requirements on the...
Reactivity on the Web: Paradigms and Applications of the Language XChange
- J. of Web Engineering
, 2005
"... 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. Reactivity plays an important role for upcoming Web systems such as online marketplac ..."
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Cited by 60 (37 self)
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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. Reactivity plays an important role for upcoming Web systems such as online marketplaces, adaptive, Semantic Web systems as well as Web services and Grids. After motivating the need for reactivity on the Web through an application scenario, this article introduces the paradigms upon which the high-level language XChange for programming reactive behaviour and distributed applications on the Web relies. Then, it briefly presents the main syntactical constructs of XChange. Finally, it sketches the implementation of a reactive Web-based application in XChange. 1
Event Composition in Time-dependent Distributed Systems
- IN COOPIS
, 1999
"... Many interesting application systems, ranging from workflow management and CSCW to air traffic control, are eventdriven and time-dependent and must interact with heterogeneous components in the real world. Event services are used to glue together distributed components. They assume a virtual gl ..."
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Cited by 55 (11 self)
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Many interesting application systems, ranging from workflow management and CSCW to air traffic control, are eventdriven and time-dependent and must interact with heterogeneous components in the real world. Event services are used to glue together distributed components. They assume a virtual global time base to trigger actions and to order events.
Two Approaches to Event Definition
- In Proc. Int. Conf. on Database and Expert Systems Applications
, 2002
"... We compare two approaches to event definition, deriving from the Active Database and Knowledge Representation communities. We relate these approaches by taking a system of the former kind, displaying some of its shortcomings, and rectifying them by remodelling the system in the latter style. We furt ..."
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Cited by 48 (5 self)
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We compare two approaches to event definition, deriving from the Active Database and Knowledge Representation communities. We relate these approaches by taking a system of the former kind, displaying some of its shortcomings, and rectifying them by remodelling the system in the latter style. We further show the extent to which the original system can be recreated within the remodelled system. This bridge between the two approaches should provide a starting point for fruitful interaction between the two communities.
Temporal Conditions and Integrity Constraints in Active Database Systems
- Proc. SIGMOD Int. Conf. Management of Data
, 1995
"... In this paper, we present a unified formalism, based on Past Temporal Logic, for specifying conditions and events in the rules for active database system. This language permits specification of many time varying properties of database systems. It also permits specification of temporal aggregates. We ..."
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Cited by 44 (3 self)
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In this paper, we present a unified formalism, based on Past Temporal Logic, for specifying conditions and events in the rules for active database system. This language permits specification of many time varying properties of database systems. It also permits specification of temporal aggregates. We present an efficient incremental algorithm for detecting conditions specified in this language. The given algorithm, for a subclass of the logic, was implemented on top of Sybase. 0 1 Introduction The most popular model of rules in active database systems is the ECA model [41, 6, 28, 5, 14, 18]. It defines a rule to consist of three parts, event, condition, and action. The semantics is that whenever the event happens, the condition (which is usually a database query) is evaluated, and if satisfied then the action is taken. The event may be composite and temporal, such as, transaction A starts after transaction B ended. However, the condition is static in the sense that it refers to the cu...
Modeling Processes and Workflows by Business Rules
, 1998
"... this paper we describe the constructs and fundamental concepts of a rule-based method for modeling business processes and the specification of workflows. In chapter 2 we discuss the meaning, notation and origin of business rules and their suitability for modeling of business processes. The third cha ..."
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Cited by 35 (0 self)
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this paper we describe the constructs and fundamental concepts of a rule-based method for modeling business processes and the specification of workflows. In chapter 2 we discuss the meaning, notation and origin of business rules and their suitability for modeling of business processes. The third chapter shows how different types of control flows can be described by business rules. The fourth chapter deals with some extensions to the business rule approach, particularly with constructs for representing a data model and an organizational model. The refinement process is described in chapter 5. 2 Business Rules 2.1 Definition
