Software systems increasingly interact with each other, forming ecosystems. Cloud is one such ecosystem that has evolved and enabled other technologies like IoT and containers. Such systems are very complex and heterogeneous because their components can have diverse origins, functions, security policies, and communication protocols, which makes it difficult to comprehend, utilize and consequently secure them. Abstract architectural models can be used to handle this complexity and heterogeneity but there is lack of work on precise, implementation/vendor neutral and holistic models which represent ecosystem components and their mutual interactions. We attempted to find similarities in systems and generalize to create abstract models for adding security. We represented the ecosystem as a Reference architecture (RA) and the ecosystem units as patterns. We started with a pattern diagram which showed all the components involved along with their mutual interactions and dependencies. We added components to the already existent Cloud security RA (SRA). Containers, being relatively new virtualization technology, did not have a precise and holistic reference architecture. We have built a partial RA for containers by identifying and modeling components of the ecosystem. Container security issues were identified from the literature as well as analysis of our patterns. We added corresponding security countermeasures to container RA as security patterns to build a container SRA. Finally, using container SRA as an example, we demonstrated an approach for RA validation. We have also built a composite pattern for fog computing that is an intermediate platform between Cloud and IoT devices. We represented an attack, Distributed Denial of Service (DDoS) using IoT devices, in the form of a misuse pattern which explains it from the attacker’s perspective. We found this modelbased approach useful to build RAs in a flexible and incremental way as components can be identified and added as the ecosystems expand. This provided us better insight to analyze security issues across boundaries of individual ecosystems. A unified, precise and holistic view of the system is not just useful for adding or evaluating security, this approach can also be used to ensure compliance, privacy, safety, reliability and/or governance for cloud and related ecosystems. This is the first work we know of where patterns and RAs are used to represent ecosystems and analyze their security. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

[pt] A apresentação de aplicações hipermídia dinâmicas pode ser vista em alguns casos como um processo de autoria recursivo, no qual aplicações são recriadas em tempo de apresentação quando modificações no conteúdo são desencadeadas por interações entre a máquina de apresentação e outras entidades (tais como usuários, objetos imperativos, aplicações externas etc.). Em alguns cenários de aplicações hipermídia dinâmicas, é possível identificar um padrão de composição hipermídia que se mantém mesmo após o documento ter sido recriado. Aplicações desse tipo são comuns, por exemplo, em um ambiente de TV Digital Interativa. A existência de um padrão durante a apresentação de uma aplicação para TV Digital Interativa permite estabelecer uma analogia entre os processos de recriar documentos dinamicamente e de especificar aplicações pelo método orientado a templates. Nesse último método, o autor especifica uma aplicação preenchendo lacunas deixadas por um template que representa o padrão de composição hipermídia da aplicação. Analogamente, na recriação dinâmica de documentos o módulo que processa atualizações no documento faz o papel de preencher as lacunas de templates. O objetivo principal do presente trabalho é definir uma arquitetura, inspirada nessa analogia, para estruturar aplicações NCL que podem ser refatoradas dinamicamente e que se mantêm em conformidade com seus respectivos templates. Nested Context Language (NCL) é a linguagem para autoria de aplicações do Sistema Brasileiro de TV Digital terrestre. Para validar a solução proposta, foram desenvolvidas uma aplicação que captura um cenário real de uso e uma ferramenta de autoria que permite especificar graficamente o preenchimento de templates. / [en] The presentation of dynamic hypermedia applications may be seen as a recursive authoring process, in which applications are recreated during presentation time, whenever content changes are triggered by interactions between the presentation engine and other entities such as users, imperative objects, external applications, etc. In some scenarios of dynamic hypermedia applications, it is possible to identify a hypermedia composition pattern that remains consistent even after the document is recreated. This kind of applications is common, for instance, in an Interactive Digital Television environment. The presence of such a pattern throughout the presentation of an application for Interactive Digital Television allows the establishment of an analogy between recreating documents dynamically and authoring applications through a template-driven authoring method. Using the latter, the authoring process is conducted by filling gaps left by a template that represents the hypermedia composition pattern of an application. Analogously, in the dynamic document re-creation, the module that processes document updates fulfills the role of filling the templates gaps. The main goal of the present work is to define an architecture, inspired by this analogy, to structure NCL applications that can be dynamically refactored and that remain conform to their respective templates. Nested Context Language (NCL) is the language of Brazilian System of Digital Terrestrial Television applications. In order to validate the proposal, an application that captures a real scenario and an authoring tool for specify graphically document filling was developed.

Manufacturing, under the umbrella of the latest industrial revolution, has gone through enormous changes in the last decades to then later evolve in what we know now as smart manufacturing. Different companies and entities have developed their own versions of architectures for intelligentand digitalized manufacturing systems. Ideating a exible and safe architecture is one of the first steps towards a system that intends to be applicable in different environments, regardless of the vast variety of possibilities available. For this purpose, the following thesis presents an investigation on the state-of-the-art solutions of the most recent digitalized cloud-based system architectures in the domain of discreet manufacturing. Based on an initial system architecture conceived from the company ABB, an evaluation of this architecture was conducted, by taking in consideration the existing systematical approaches to the digitalization of this industry. In the following thesis work, we investigate, describe and evaluate the limitations and strengths of the most recent and known architectural approaches to cloud robotics. Finally, a few key remarks are made towards ABB's initial solution but also to the industry in general. / PADME

Software evolution is a crucial activity for software organizations. A specifc type of software evolution is the integration of previously isolated systems. The need for integration is often a consequence of different organizational changes, including merging of previously separate organizations. One goal of software integration is to increase the value to users of several systems by combining their functionality, another is to reduce functionality overlap. If the systems are completely owned and controlled in-house, there is an additional advantage in rationalizing the use of internal resources by decreasing the amount of software with essentially the same purpose. Despite in-house integration being common, this topic has received little attention from researchers. This thesis contributes to an increasing understanding of the problems associated with in-house integration and provides guidelines to the more efficient utilization of the existing systems and the personnel. In the thesis, we combine two perspectives: software architecture and processes. The perspective of software architecture is used to show how compatibility analysis and development of integration alternatives can be performed rapidly at a high level of abstraction. The software process perspective has led to the identification of important characteristics and practices of the integration process. The guidelines provided in the thesis will help those performing future in-house integration to make well-founded decisions timely and efficiently. The contributions are based on several integration projects in industry, which have been studied systematically in order to collect, evaluate and generalize their experiences.

Contemporary software engineering practice overemphasizes the distinction of software design from software implementation, and designer (“software architect”) from implementor (“computer programmer”). In this contemporary meme, software architects are concerned with large-grained system structures, quality attributes that arise from these structures (security, availability, performance, etc.) and quality attribute tradeoff to satisfy conflicting stakeholder needs; programmers are concerned with low–level algorithms and data structures, program functionality, and with satisfying architectural intent. However, software is unique in that design and implementation are not cleanly separable. While architect and programmer may have many different design concerns, they also have many complementary and interacting concerns; their respective design practices must be well–integrated. Instead, contemporary architecture and programming practices are diverging. Architects are likely to regard programming as a routine production activity, while programmers are likely to regard architecture as a routine management activity; communication is hindered by a lack of shared vocabulary or appreciation of mutual concerns. Instead of effective integration, a gap has opened in software architecture and programming practice. The research reported here defines the architecture/program seam (“the Seam”), a region of overlap in software architecture and programming practice. The Seam emphasizes design concerns centered on achieving predictable runtime behavior. For a behavior to be predictable it must be described in a theory that must ultimately be consistent with basic theories of computation, and each such theory must have objective evidence to demonstrate that theory observations correspond to system observations. The validity of a theory will likely depend on invariants that can be expressed, and enforced, by means of theory–induced design rules. A system that satisfies the design rules of a theory is then regarded as having behavior that is predictable by construction with respect to that theory. Predictability by construction reduces uncertainty, and hence risk in design, and helps designers explain complex design decisions. The research reported here also defines prediction–enabled component technology (PECT) as a foundation technology to support the Seam, and demonstrates a prototype on industrial problems in electric grid substation control, industrial robot control, and desktop streaming audio. The prototype PECT extends a basic component technology of pure assembly (“Pin”) with theory extension points (“reasoning frameworks”) that are used to achieve predictability by construction. Reasoning frameworks for real–time performance and temporal–logic model checking have been developed, with statistical confidence intervals providing evidence of predictive quality for the former, and code–embeddable proof certificates providing evidence for the latter. Finally, the research reported here defines the Seam itself as inducing a new kind of evolutionary design problem, whose solutions require the integration of programming language theory, design theory, specialized theories of system behavior and deep systems expertise.

The purpose of the architecture of software systems in business organizations is to support those organizations in achieving business goals. In software development organizations the design of an architecture is a collective effort that involves various organizational stakeholders and designers, who identify, interpret, and reason about intents, and communicate, delegate, commit to, and implement intents and decisions. Current architectural design descriptions are by-and-large based on block-and-arrow notations representing "coarse-grained" solution elements of the system. They lack explicit representation for modeling and analyzing the decision-making of stakeholders and architectural designers who hold different organizational responsibilities, and pursue conflicting and/or synergistic business or system goals, while collectively pursuing organizational objectives. This thesis considers the proposition that a distributed intentionality perspective is applicable in the design of software system architectures. During architectural design, relationships between intentional actors define the context in which intentional actors pursue business and system goals and in which they negotiate architectural decision-making. The objective of this research is to investigate what an Intentional Architecture Language (IAL) could be like that utilizes intentional and organizational modeling and analysis concepts to support architectural decision-making efforts in organizational settings. Drawing from prior work on organizational modeling and analysis, this thesis first defines a core IAL, and then explores its use to model and analyze architectural decision-making both reported in the literature and empirically observed at a number of commercial projects in industry. Drawing from these explorations, this thesis proposes a number of extensions to the core IAL, discusses lessons learned, and points to the advantages and limitations in using an IAL to model and analyze architectural decision-making in an organizational setting.

The purpose of the architecture of software systems in business organizations is to support those organizations in achieving business goals. In software development organizations the design of an architecture is a collective effort that involves various organizational stakeholders and designers, who identify, interpret, and reason about intents, and communicate, delegate, commit to, and implement intents and decisions. Current architectural design descriptions are by-and-large based on block-and-arrow notations representing "coarse-grained" solution elements of the system. They lack explicit representation for modeling and analyzing the decision-making of stakeholders and architectural designers who hold different organizational responsibilities, and pursue conflicting and/or synergistic business or system goals, while collectively pursuing organizational objectives. This thesis considers the proposition that a distributed intentionality perspective is applicable in the design of software system architectures. During architectural design, relationships between intentional actors define the context in which intentional actors pursue business and system goals and in which they negotiate architectural decision-making. The objective of this research is to investigate what an Intentional Architecture Language (IAL) could be like that utilizes intentional and organizational modeling and analysis concepts to support architectural decision-making efforts in organizational settings. Drawing from prior work on organizational modeling and analysis, this thesis first defines a core IAL, and then explores its use to model and analyze architectural decision-making both reported in the literature and empirically observed at a number of commercial projects in industry. Drawing from these explorations, this thesis proposes a number of extensions to the core IAL, discusses lessons learned, and points to the advantages and limitations in using an IAL to model and analyze architectural decision-making in an organizational setting.

The Service-Oriented Architecture (SOA) has become one of the most popular approaches to building large-scale network applications. The web service technologies are de facto the default implementation for SOA. Simple Object Access Protocol (SOAP) is the key and fundamental technology of web services. Service composition is a way to deliver complex services based on existing partner services. Service orchestration with the support of Web Services Business Process Execution Language (WSBPEL) is the dominant approach of web service composition. WSBPEL-based service orchestration inherited the issue of interoperability from SOAP, and it was furthermore challenged for performance, scalability, reliability and modifiability. I present an architectural approach for service composition in this thesis to address these challenges. An architectural solution is so generic that it can be applied to a large spectrum of problems. I name the architectural style RESTful Service Composition (RSC), because many of its elements and constraints are derived from Representational State Transfer (REST). REST is an architectural style developed to describe the architectural style of the Web. The Web has demonstrated outstanding interoperability, performance, scalability, reliability and modifiability. RSC is designed for service composition on the Internet. The RSC style is composed on specific element types, including RESTful service composition client, RESTful partner proxy, composite resource, resource client, functional computation and relaying service. A service composition is partitioned into stages; each stage is represented as a computation that has a uniform identifier and a set of uniform access methods; and the transitions between stages are driven by computational batons. RSC is supplemented by a programming model that emphasizes on-demand function, map-reduce and continuation passing. An RSC-style composition does not depend on either a central conductor service or a common choreography specification, which makes it different from service orchestration or service choreography. Four scenarios are used to evaluate the performance, scalability, reliability and modifiability improvement of the RSC approach compared to orchestration. An RSC-style solution and an orchestration solution are compared side by side in every scenario. The first scenario evaluates the performance improvement of the X-Ray Diffraction (XRD) application in ScienceStudio; the second scenario evaluates the scalability improvement of the Process Variable (PV) snapshot application; the third scenario evaluates the reliability improvement of a notification application by simulation; and the fourth scenario evaluates the modifiability improvement of the XRD application in order to fulfil emerging requirements. The results show that the RSC approach outperforms the orchestration approach in every aspect.

Many software development projects start with an existing code base that has to be tightly integrated into a new system. In order to make a robust system that will achieve the desired business goals, developers must be able to understand the architecture of the old code base and its rationale. This thesis presents a lightweight approach for the recovery of software architecture. The main goal of the approach is to provide an efficient way for architecture recovery that works on small to mid-sized software systems, and gives a useful starting point on large ones. The emphasis of the process is on the use of well established development techniques and tools, in order to minimize adoption costs and maximize the return on investment.

An object-oriented software system is composed of a collection of communicating objects that co-operate with one another to achieve some desired goals. The object is the basic unit of abstraction in an OO program; objects may model real-world entities or internal abstractions of the system. Similar objects forms classes, which encapsulate the data and operations performed on the data. Therefore, extracting, analyzing, and modelling classes/objects and their relationships is of key importance in understanding and maintaining object-oriented software systems. However, when dealing with large and complex object-oriented systems, maintainers can easily be overwhelmed by the vast number of classes/objects and the high degree of interdependencies among them. In this thesis, we propose a new model, which we call the Hybrid Model, to represent object-oriented systems at a coarse-grained level of abstraction. To promote the comprehensibility of objects as independent units, we group the complete static description of software objects into aggregate components. Each aggregate component logically represents a set of objects, and the components interact with one other through explicitly defined ports. We present and discuss several applications of the Hybrid Model in reverse engineering and software evolution. The Hybrid Model can be used to support a divide-and-conquer comprehension strategy for program comprehension. At a low level of abstraction, maintainers can focus on one aggregate-component at a time, while at a higher level, each aggregate component can be understood as a whole and be mapped to coarse-grained design abstractions, such as subsystems. Based on the new model, we further propose a set of dependency analysis methods. The analysis results reveal the external properties of aggregate components, and lead to better understand the nature of their interdependencies. In addition, we apply the new model in software evolution analysis. We identify a collection of change patterns in terms of changes in aggregate components and their interrelationships. These patterns help to interpret how an evolving system changes at the architectural level, and provides valuable information to understand why the system is designed as the way it is.