物件導向軟體之架構(Object-Oriented Software Construction)探討

[서평]「Component Software」 - Beyond Object-Oriented Programming -

A new class of models, formalisms and mechanisms has recently evolved for describing concurrent and distributed computations based on the concept of ``coordination''''. The purpose of a coordination model and associated language is to provide a means of integrating a number of possibly heterogeneous components together, by interfacing with each component in such a way that the collective set forms a single application that can execute on and take advantage of parallel and distributed systems. In this chapter we initially define and present in sufficient detail the fundamental concepts of what constitutes a coordination model or language. We then go on to classify these models and languages as either ``data-driven'''' or ``control-driven'''' (also called ``process-'''' or ``task-oriented''''). Next, the main existing coordination models and languages are described in sufficient detail to let the reader appreciate their features and put them into perspective with respect to each other. The chapter ends with a discussion comparing the various models and some conclusions.

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Coordination models and languages

A super-peer is a node in a peer-to-peer network that operates both as a server to a set of clients, and as an equal in a network of super-peers. Super-peer networks strike a balance between the efficiency of centralized search, and the autonomy, load balancing and robustness to attacks provided by distributed search. Furthermore, they take advantage of the heterogeneity of capabilities (e.g., bandwidth, processing power) across peers, which recent studies have shown to be enormous. Hence, new and old P2P systems like KaZaA and Gnutella are adopting super-peers in their design. Despite their growing popularity, the behavior of super-peer networks is not well understood. For example, what are the potential drawbacks of super-peer networks? How can super-peers be made more reliable? How many clients should a super-peer take on to maximize efficiency? we examine super-peer networks in detail, gaming an understanding of their fundamental characteristics and performance tradeoffs. We also present practical guidelines and a general procedure for the design of an efficient super-peer network.

Designing an Super-Peer Network

All one needs to know about fog computing and related edge computing paradigms: A complete survey

CISCO FogDirector is one of the first available tools supporting the management of the entire life cycle of applications deployed to Fog infrastructures. In this paper, we present a simple operational semantics of the main features of FogDirector, which provides a compact reference for the tool. We then introduce a prototype, based on such semantics, that can constitute the core of a simulation environment of FogDirector application management. The usefulness of the prototype is illustrated over a motivating example.

Mimicking FogDirector application management

Exploiting microservices to architect enterprise applications is becoming commonplace. This makes it crucial to provide some support for designing and analyzing microservice‐based applications, for example, for understanding whether a microservice‐based application adheres to the main design principles of microservices and for choosing how to refactor it when this is not the case. To provide such support, in this article we present the μ TOSCA toolchain. More precisely, we first introduce the μ TOSCA model to represent the architecture of microservice‐based applications with the OASIS standard TOSCA. We then describe a technique to automatically mine the architecture of a microservice‐based application and represent it with μ TOSCA, given the Kubernetes deployment of the application. We also present a methodology to analyze the μ TOSCA representation of a microservice‐based architecture to systematically identify the architectural smells potentially affecting the corresponding application and to resolve them. Finally, we present two prototype tools, μMiner and μFreshener, implementing our mining solution and the support for identifying and resolving architectural smells in microservice‐based applications, respectively. We then assess —by discussing some case studies— how effectively μMiner, μFreshener, and the μ TOSCA toolchain can support researchers and practitioners working with microservices.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/spe.2974

The μTOSCA toolchain: Mining, analyzing, and refactoring microservice‐based architectures

We use metalogic to define a suitable notion of module in logic programming. A module is viewed as a pair of logic programs, corresponding to the visible and the hidden part of the module, respectively. The construction of a module is implemented through a metalevel composition operator of object-level logic programs. We introduce metalevel operators for combining separate modules together. All the operators are straightforwardly defined by extending the standard vanilla metainterpreter with new clauses. More importantly, the semantics of modules and module composition operators is defined in terms of the standard semantics of logic programming in a compositional way.

Meta for Modularising Logic Programming

An important branch of investigation in the field of agents has been the definition of high level languages for representing effects of actions, the programs written in such languages being usually called action programs. Logic programming is an important area in the field of knowledge representation and some languages for specifying updates of Logic Programs had been defined. Starting from the update language Evolp, in this work we propose a new paradigm for reasoning about actions called Evolp action programs.

We provide translations of some of the most known action description languages into Evolp action programs, and underline some peculiar features of this newly defined paradigm. One such feature is that Evolp action programs can easily express changes in the rules of the domains, including rules describing changes.

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From logic programs updates to action description updates

https://biblio.ugent.be/publication/976021/file/976022.pdf

Antonio Brogi

Papers

Mimicking FogDirector application management

The μTOSCA toolchain: Mining, analyzing, and refactoring microservice‐based architectures

Meta for Modularising Logic Programming

From logic programs updates to action description updates

On the expressiveness of timed coordination models