Semantic Foundations for Deterministic Dataflow and Stream Processing

AbstractWe propose a denotational semantic framework for deterministic dataflow and stream processing that encompasses a variety of existing streaming models. Our proposal is based on the idea that data streams, stream transformations, and stream-processing programs should be classified using types. The type of a data stream is captured formally by a monoid, an algebraic structure with a distinguished binary operation and a unit. The elements of a monoid model the finite fragments of a stream, the binary operation represents the concatenation of stream fragments, and the unit is the empty fragment. Stream transformations are modeled using monotone functions on streams, which we call stream transductions. These functions can be implemented using abstract machines with a potentially infinite state space, which we call stream transducers. This abstract typed framework of stream transductions and transducers can be used to (1) verify the correctness of streaming computations, that is, that an implementation adheres to the desired behavior, (2) prove the soundness of optimizing transformations, e.g. for parallelization and distribution, and (3) inform the design of programming models and query languages for stream processing. In particular, we show that several useful combinators can be supported by the full class of stream transductions and transducers: serial composition, parallel composition, and feedback composition.

Download Full-text

Split-2 Bisimilarity has a Finite Axiomatization over CCS with Hennessy's Merge

BRICS Report Series ◽

10.7146/brics.v11i1.21826 ◽

2004 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Luca Aceto ◽

Willem Jan Fokkink ◽

Anna Ingólfsdóttir ◽

Bas Luttik

Keyword(s):

Process Algebra ◽

Binary Operation ◽

Sharp Contrast ◽

Parallel Composition ◽

Finitely Based ◽

Finite Axiomatization ◽

Auxiliary Operation ◽

Bisimulation Equivalence

This note shows that split-2 bisimulation equivalence (also known as timed equivalence) affords a finite equational axiomatization over the process algebra obtained by adding an auxiliary operation proposed by Hennessy in 1981 to the recursion free fragment of Milner's Calculus of Communicating Systems. Thus the addition of a single binary operation, viz. Hennessy's merge, is sufficient for the finite equational axiomatization of parallel composition modulo this non-interleaving equivalence. This result is in sharp contrast to a theorem previously obtained by the same authors to the effect that the same language is not finitely based modulo bisimulation equivalence.

Download Full-text

XKFitler

International Journal of Information Retrieval Research ◽

10.4018/ijirr.2011010101 ◽

2011 ◽

Vol 1 (1) ◽

pp. 1-18 ◽

Cited By ~ 1

Author(s):

Weidong Yang ◽

Fei Fang ◽

Nan Li ◽

Zhongyu (Joan) Lu

Keyword(s):

Common Ancestor ◽

Keyword Search ◽

Stream Processing ◽

Query Languages ◽

Information Discovery ◽

Text Documents ◽

Filter System ◽

Lowest Common Ancestor ◽

Xml Stream ◽

User Friendly

Most existing XML stream processing systems adopt full structured query languages, such as XPath or XQuery, but they are difficult for ordinary users to learn and use. Keyword search is a user-friendly information discovery technique that has been extensively studied for text documents. This paper presents an XML stream filter system called XKFitler, which is the first system for supporting keyword search over XML stream. In XKFitler, the concepts of XLCA (eXclusive Lowest Common Ancestor) and XLCA Connecting Tree (XLCACT) are used to define the search semantic and results of keywords, and present an approach to filter XML stream according to keywords. The prototype XKFilter is implemented in the experiments.

Download Full-text

XKFilter

Information Retrieval Methods for Multidisciplinary Applications ◽

10.4018/978-1-4666-3898-3.ch001 ◽

2013 ◽

pp. 1-18

Author(s):

Weidong Yang ◽

Fei Fang ◽

Nan Li ◽

Zhongyu (Joan) Lu

Keyword(s):

Common Ancestor ◽

Keyword Search ◽

Stream Processing ◽

Query Languages ◽

Information Discovery ◽

Text Documents ◽

Filter System ◽

Lowest Common Ancestor ◽

Xml Stream ◽

User Friendly

Most existing XML stream processing systems adopt full structured query languages, such as XPath or XQuery, but they are difficult for ordinary users to learn and use. Keyword search is a user-friendly information discovery technique that has been extensively studied for text documents. This paper presents an XML stream filter system called XKFilter, which is the first system for supporting keyword search over XML stream. In XKFilter, the concepts of XLCA (eXclusive Lowest Common Ancestor) and XLCA Connecting Tree (XLCACT) are used to define the search semantic and results of keywords, and present an approach to filter XML stream according to keywords. The prototype XKFilter is implemented in the experiments.

Download Full-text

RSP-QL Semantics

International Journal on Semantic Web and Information Systems ◽

10.4018/ijswis.2014100102 ◽

2014 ◽

Vol 10 (4) ◽

pp. 17-44 ◽

Cited By ~ 38

Author(s):

Daniele Dell'Aglio ◽

Emanuele Della Valle ◽

Jean-Paul Calbimonte ◽

Oscar Corcho

Keyword(s):

Data Streams ◽

Operational Semantics ◽

Stream Processing ◽

Query Languages ◽

Continuous Query ◽

Comprehensive Model ◽

Continuous Processing ◽

Data Interchange ◽

The Web

RDF and SPARQL are established standards for data interchange and querying on the Web. While they have been shown to be useful and applicable in many scenarios, they are not sufficiently adequate for dealing with streams of data and their intrinsic continuous nature. In the last years data and query languages have been proposed to extend both RDF and SPARQL for streams and continuous processing, under the name of RDF Stream Processing – RSP. These efforts resulted in several models and implementations that, at a first look, appear to propose alternative syntaxes but equivalent semantics. However, when asked to continuously answer the same queries on the same data streams, they provide different answers at disparate moments due to the heterogeneity of their operational semantics. These discrepancies render the process of understanding and comparing continuous query results complex and misleading. In this work, the authors propose RSP-QL, a comprehensive model that formally defines the semantics of an RSP system. RSP-QL makes explicit the hidden assumptions of currently available RSP systems, allows defining a formal notion of correctness for RSP query results and, thus, explains why available implementations provide different answers at disparate moments.

Download Full-text

Stream Processing on Multi-cores with GPUs: Parallel Programming Models' Challenges

2019 IEEE International Parallel and Distributed Processing Symposium Workshops (IPDPSW) ◽

10.1109/ipdpsw.2019.00137 ◽

2019 ◽

Author(s):

Dinei A. Rockenbach ◽

Charles M. Stein ◽

Dalvan Griebler ◽

Gabriele Mencagli ◽

Massimo Torquati ◽

...

Keyword(s):

Parallel Programming ◽

Stream Processing ◽

Programming Models ◽

Parallel Programming Models

Download Full-text

Verifying infinite state processes with sequential and parallel composition

Proceedings of the 22nd ACM SIGPLAN-SIGACT symposium on Principles of programming languages - POPL '95 ◽

10.1145/199448.199470 ◽

1995 ◽

Cited By ~ 13

Author(s):

Ahmed Bouajjani ◽

Rachid Echahed ◽

Peter Habermehl

Keyword(s):

Parallel Composition ◽

Infinite State

Download Full-text

A Query Model to Capture Event Pattern Matching in RDF Stream Processing Query Languages

Lecture Notes in Computer Science - Knowledge Engineering and Knowledge Management ◽

10.1007/978-3-319-49004-5_10 ◽

2016 ◽

pp. 145-162 ◽

Cited By ~ 8

Author(s):

Daniele Dell’Aglio ◽

Minh Dao-Tran ◽

Jean-Paul Calbimonte ◽

Danh Le Phuoc ◽

Emanuele Della Valle

Keyword(s):

Pattern Matching ◽

Stream Processing ◽

Query Languages ◽

Capture Event ◽

Query Model

Download Full-text

Positivity, Betweenness, and Strictness of Operator Means

Abstract and Applied Analysis ◽

10.1155/2015/851568 ◽

2015 ◽

Vol 2015 ◽

pp. 1-5 ◽

Cited By ~ 2

Author(s):

Pattrawut Chansangiam

Keyword(s):

Fixed Point ◽

Binary Operation ◽

Point Property ◽

Monotone Functions ◽

Operator Equations ◽

Operator Inequalities ◽

Borel Measures ◽

Operator Monotone ◽

Operator Means ◽

Operator Monotone Functions

An operator mean is a binary operation assigned to each pair of positive operators satisfying monotonicity, continuity from above, the transformer inequality, and the fixed-point property. It is well known that there are one-to-one correspondences between operator means, operator monotone functions, and Borel measures. In this paper, we provide various characterizations for the concepts of positivity, betweenness, and strictness of operator means in terms of operator inequalities, operator monotone functions, Borel measures, and certain operator equations.

Download Full-text