Multitier Modules

Multitier programming languages address the complexity of developing distributed systems abstracting over low level implementation details such as data representation, serialization and network protocols. Since the functionalities of different peers can be defined in the same compilation unit, multitier languages do not force developers to modularize software along network boundaries. Unfortunately, combining the code for all tiers into the same compilation unit poses a scalability challenge or forces developers to resort to traditional modularization abstractions that are agnostic to the multitier nature of the language. In this paper, we address this issue with a module system for multitier languages. Our module system supports encapsulating each (cross-peer) functionality and defining it over abstract peer types. As a result, we disentangle modularization and distribution and we enable the definition of a distributed system as a composition of multitier modules, each representing a subsystem. Our case studies on distributed algorithms, distributed data structures, as well as on the Apache Flink task distribution system, show that multitier modules allow the definition of reusable (abstract) patterns of interaction in distributed software and enable separating the modularization and distribution concerns, properly separating functionalities in distributed systems

Advances in the Design and Implementation of a Multi-Tier Architecture in the GIPSY Environment

We present advances in the software engineering design and implementation of the multi-tier run-time system for the General Intensional Programming System (GIPSY) by further unifying the distributed technologies used to implement the Demand Migration Framework (DMF) in order to streamline distributed execution of hybrid intensional-imperative programs using Java.Comment: 11 pages, 3 figure

Multiparty Languages: The Choreographic and Multitier Cases (Pearl)

Choreographic languages aim to express multiparty communication protocols, by providing primitives that make interaction manifest. Multitier languages enable programming computation that spans across several tiers of a distributed system, by supporting primitives that allow computation to change the location of execution. Rooted into different theoretical underpinnings - respectively process calculi and lambda calculus - the two paradigms have been investigated independently by different research communities with little or no contact. As a result, the link between the two paradigms has remained hidden for long. In this paper, we show that choreographic languages and multitier languages are surprisingly similar. We substantiate our claim by isolating the core abstractions that differentiate the two approaches and by providing algorithms that translate one into the other in a straightforward way. We believe that this work paves the way for joint research and cross-fertilisation among the two communities

Functional Choreographic Programming

Choreographic programming is an emerging programming paradigm for concurrent and distributed systems, whereby developers write the communications that should be enacted and then a distributed implementation is automatically obtained by means of a compiler. Theories of choreographic programming typically come with strong theoretical guarantees about the compilation process, most notably: the generated implementations operationally correspond to their source choreographies and are deadlock-free. Currently, the most advanced incarnation of the paradigm is Choral, an object-oriented choreographic programming language that targets Java. Choral deviated significantly from known theories of choreographies, and introduced the possibility of expressing higher-order choreographies (choreographies parameterised over choreographies) that are fully distributed. As a consequence, it is unclear if the usual guarantees of choreographies can still hold in the more general setting of higher-order ones. We introduce Chor{\lambda}, the first functional choreographic programming language: it introduces a new formulation of the standard communication primitive found in choreographies as a function, and it is based upon the {\lambda}-calculus. Chor{\lambda} is the first theory that explains the core ideas of higher-order choreographic programming (as in Choral). Bridging the gap between practice and theory requires developing a new evaluation strategy and typing discipline for {\lambda} terms that accounts for the distributed nature of computation in choreographies. We illustrate the expressivity of Chor{\lambda} with a series of examples, which include reconstructions of the key examples from the original presentation of Choral. Our theory supports the expected properties of choreographic programming and bridges the gap between the communities of functional and choreographic programming

Towards a Safe and Secure web semantic framework

This thesis describes the work I did during my internship at the INRIA research center in Sophia-Antipolis, within the INDES team and under the supervision of Ilaria Castellani and Tamara Rezk.The main objectives of the INDES team is to study models and develop languages for Diffuse computing, a computing paradigm in which it is necessary to manage and maintain computing structures distributed on several heterogeneous nodes that usually do not trust each other. INDES focuses on the study of the different concurrency models that underlie these systems and pays particular attention to Multitier programming, an emerging programming paradigm that aims to reduce complexity in the development of web applications by adopting a single language to program all their components. The role played by security issues (and particularly the protection of confidentiality and integrity of data) is crucial in these applications, and ensuring security of web applications is another important goal of the INDES team. My internship took place in the context of the ANR CISC project, whose objective is to provide semantics, languages and attack models for the Internet of Things (IoT), a term that refers to systems composed of a set of interconnected devices, which interact with the environment in which they are placed by means of different sensors and actuators. My individual research took place within Webi, a semantic framework that aims at a primitive simulation of the interactions that take place between servers and clients on the web, developed by Tamara Rezk and her colleagues. In particular, I concentrated on an extension of Webi called WebiLog, which allows one to represent authenticated sessions and to formalize attacks aimed at compromising their integrity