46,319 research outputs found
Adaptive network protocols to support queries in dynamic networks
Recent technological advancements have led to the popularity of mobile devices, which can dynamically form wireless networks. In order to discover and obtain distributed information, queries are widely used by applications in opportunistically formed mobile networks. Given the popularity of this approach, application developers can choose from a number of implementations of query processing protocols to support the distributed execution of a query over the network. However, different inquiry strategies (i.e., the query processing protocol and associated parameters used to execute a query) have different tradeoffs between the quality of the query's result and the cost required for execution under different operating conditions. The application developer's choice of inquiry strategy is important to meet the application's needs while considering the limited resources of the mobile devices that form the network. We propose adaptive approaches to choose the most appropriate inquiry strategy in dynamic mobile environments. We introduce an architecture for adaptive queries which employs knowledge about the current state of the dynamic mobile network and the history of previous query results to learn the most appropriate inquiry strategy to balance quality and cost tradeoffs in a given setting, and use this information to dynamically adapt the continuous query's execution
From Inception to Execution: Query Management for Complex Event Processing as a Service
International audienceComplex Event Processing (CEP) is a set of tools and techniques that can be used to obtain insights from high- volume, high-velocity continuous streams of events. CEP-based systems have been adopted in many situations that require prompt establishment of system diagnostics and execution of reaction plans, such as in monitoring of complex systems. This article describes the Query Analyzer and Manager (QAM) mod- ule, a first effort toward the development of a CEP as a Service (CEPaaS) system. This module is responsible for analyzing user-defined CEP queries and for managing their execution in distributed cloud-based environments. Using a language-agnostic internal query representation, QAM has a modular design that enables its adoption by virtually any CEP system
Query Analyzer and Manager for Complex Event Processing as a Service
Complex Event Processing (CEP) is a set of tools and techniques that can be used to obtain insights from high-volume, high-velocity continuous streams of events. CEP-based systems have been adopted in many situations that require prompt establishment of system diagnostics and execution of reaction plans, such as in monitoring of complex systems. This article describes the Query Analyzer and Manager (QAM) module, a first effort toward the development of a CEP as a Service (CEPaaS) system. This module is responsible for analyzing user-defined CEP queries and for managing their execution in distributed cloud-based environments. Using a language-agnostic internal query representation, QAM has a modular design that enables its adoption by virtually any CEP system
Towards Analytics Aware Ontology Based Access to Static and Streaming Data (Extended Version)
Real-time analytics that requires integration and aggregation of
heterogeneous and distributed streaming and static data is a typical task in
many industrial scenarios such as diagnostics of turbines in Siemens. OBDA
approach has a great potential to facilitate such tasks; however, it has a
number of limitations in dealing with analytics that restrict its use in
important industrial applications. Based on our experience with Siemens, we
argue that in order to overcome those limitations OBDA should be extended and
become analytics, source, and cost aware. In this work we propose such an
extension. In particular, we propose an ontology, mapping, and query language
for OBDA, where aggregate and other analytical functions are first class
citizens. Moreover, we develop query optimisation techniques that allow to
efficiently process analytical tasks over static and streaming data. We
implement our approach in a system and evaluate our system with Siemens turbine
data
S-Store: Streaming Meets Transaction Processing
Stream processing addresses the needs of real-time applications. Transaction
processing addresses the coordination and safety of short atomic computations.
Heretofore, these two modes of operation existed in separate, stove-piped
systems. In this work, we attempt to fuse the two computational paradigms in a
single system called S-Store. In this way, S-Store can simultaneously
accommodate OLTP and streaming applications. We present a simple transaction
model for streams that integrates seamlessly with a traditional OLTP system. We
chose to build S-Store as an extension of H-Store, an open-source, in-memory,
distributed OLTP database system. By implementing S-Store in this way, we can
make use of the transaction processing facilities that H-Store already
supports, and we can concentrate on the additional implementation features that
are needed to support streaming. Similar implementations could be done using
other main-memory OLTP platforms. We show that we can actually achieve higher
throughput for streaming workloads in S-Store than an equivalent deployment in
H-Store alone. We also show how this can be achieved within H-Store with the
addition of a modest amount of new functionality. Furthermore, we compare
S-Store to two state-of-the-art streaming systems, Spark Streaming and Storm,
and show how S-Store matches and sometimes exceeds their performance while
providing stronger transactional guarantees
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