An Abstract Description Method of Map-Reduce-Merge Using Haskell

Map-Reduce-Merge is an improved parallel programming model based on Map-Reduce in cloud computing environment. Through the new Merge module, Map-Reduce-Merge can support processing multiple related heterogeneous datasets more efficiently. In order to demonstrate the validity and effectiveness of this new model, we present a rigorous description for Map-Reduce-Merge model using Haskell. Firstly, we describe the basic program skeleton of Map-Reduce-Merge programming model. Secondly, an abstract description for the Merge module is presented by analyzing the structure and function of the Merge module with Haskell as the description tool. Thirdly, we evaluate the Map-Reduce-Merge model on the basis of our description. We capture the functional characteristics of the Map-Reduce-Merge model by our abstract description, which can provide theoretical basis for designing more efficient parallel programming model to process join operation

Automatically Leveraging MapReduce Frameworks for Data-Intensive Applications

MapReduce is a popular programming paradigm for developing large-scale, data-intensive computation. Many frameworks that implement this paradigm have recently been developed. To leverage these frameworks, however, developers must become familiar with their APIs and rewrite existing code. Casper is a new tool that automatically translates sequential Java programs into the MapReduce paradigm. Casper identifies potential code fragments to rewrite and translates them in two steps: (1) Casper uses program synthesis to search for a program summary (i.e., a functional specification) of each code fragment. The summary is expressed using a high-level intermediate language resembling the MapReduce paradigm and verified to be semantically equivalent to the original using a theorem prover. (2) Casper generates executable code from the summary, using either the Hadoop, Spark, or Flink API. We evaluated Casper by automatically converting real-world, sequential Java benchmarks to MapReduce. The resulting benchmarks perform up to 48.2x faster compared to the original.Comment: 12 pages, additional 4 pages of references and appendi

A DSL For Logistics Clouds

Cloud is a new area of specialization in the computing world, and, as such, it has not been explicitly addressed by traditional programming languages and environments. Therefore, there is a need to create Domain Specific Languages (DSLs) for it. This paper presents such a DSL that targets logistics clouds, i.e. networked resources and systems of logistics organisations. The DSL is implemented on top of the functional concurrent language Erlang and its distributed data management system Mnesia. The paper presents features of the DSL that implement commonly occurring use cases in the logistics cloud such as message exchange, document sharing and notifications. We show how program features in this DSL map to the underlying Erlang/OTP runtime

Programmiersprachen und Rechenkonzepte

Seit 1984 veranstaltet die GI--Fachgruppe "Programmiersprachen und Rechenkonzepte" regelmäßig im Frühjahr einen Workshop im Physikzentrum Bad Honnef. Das Treffen dient in erster Linie dem gegenseitigen Kennenlernen, dem Erfahrungsaustausch, der Diskussion und der Vertiefung gegenseitiger Kontakte

Automating abstraction functions

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 109-119).Data abstraction has been the dominant structuring paradigm for programs for decades. The essence of a data abstraction is the abstraction function, which relates the concrete program representation to its abstract meaning. However, abstraction functions are not generally considered to be a part of the executing program. We propose that making abstraction functions an executable part of the program can enable programmers to write clearer and more concise programs with fewer errors. In particular, we show that the object equality and hashing operations (which programmers are required to write), can often be expressed more clearly and more concisely in terms of the abstract state of the object. Getting these methods right has proven to be difficult for programmers at all skill levels, from novice through expert. In a case study of the standard Java libraries we show that rewriting the code with explicit declarative abstraction functions (and generating equality and hashing methods automatically) removed object-contract compliance faults previously found by Pacheco et al. To make abstraction functions part of the executing program we develop four techniques for the dynamic evaluation of abstraction functions written in a declarative first-order logic with relations and transitive closure. We observe that the abstraction functions programmers write in practice may often be viewed as navigation queries on the heap, and two of our techniques exploit this insight to synthesize executable code from declarative abstraction functions. The performance of our research prototype is within striking distance of hand-written code.by Derek F. Rayside.Ph.D

Accommodating prepositional phrases in a highly modular natural language query interface to semantic web triplestores using a novel event-based denotational semantics for English and a set of functional parser combinators

The SemanticWeb is an emerging component of the set of technologies that will be known as Web 3.0 in the future. With the large changes it brings to how information is stored and represented to users, there is a need to re-evaluate how this information can be queried. Specifically, there is a need for Natural Language Interfaces that allow users to easily query for information on the Semantic Web. While there has been previous work in this area, existing solutions suffer from the problem that they do not support prepositional phrases in queries (e.g, “in 1958” or “with a key”). To achieve this, we improve on an existing semantics for event-based triplestores that supports prepositional phrases and demonstrate a novel method of handling the word “by”, treating it directly as a preposition in queries. We then show how this new semantics can be integrated with a parser constructed as an executable attribute grammar to create a highly modular and extensible Natural Language Interface to the Semantic Web that supports prepositional phrases in queries

Maximum Segment Sum, Monadically (distilled tutorial, with solutions)

The maximum segment sum problem is to compute, given a list of integers, the largest of the sums of the contiguous segments of that list. This problem specification maps directly onto a cubic-time algorithm; however, there is a very elegant linear-time solution too. The problem is a classic exercise in the mathematics of program construction, illustrating important principles such as calculational development, pointfree reasoning, algebraic structure, and datatype-genericity. Here, we take a sideways look at the datatype-generic version of the problem in terms of monadic functional programming, instead of the traditional relational approach; the presentation is tutorial in style, and leavened with exercises for the reader.Comment: Revision of the article in Proceedings DSL 2011, EPTCS 66, arXiv:1109.0323, to provide solutions to the exercise