Amleto Di Salle

Software customization in model driven development of web applications

Model Driven Development (MDD) of complex software systems can require manual adaptations of the generated artifacts. In fact, in order to cope with unforeseen requirements which are not completely satisfiable by means of the involved modeling languages, developer interventions could be needed. The optimal solution to deal with this issue, is based on the expressiveness improvement of the involved metamodels and refinement of the used model transformations. Nevertheless, these adaptations are not always possible or cost-effective especially if the new functionalities that have to be introduced affect only the single application being developed. This paper discusses and attempt to hand-tune the generated code by providing an approach supporting its merging with hand written modifications. For this purpose, the behaviour model of the system under study is considered to graphically specify the injection points where the modifications have to occur. The discussions are based on a running example consisting of a simple Web application.

Synthesis of Resilient Choreographies

A possible Service Engineering (SE) approach to build service-based systems is to compose together distributed services by considering a global specification of their interactions, namely a choreography. BPMN2 (Business Process Modeling Notation v2.0) provides a dedicated notation, called Choreography Diagrams, to define the global expected behavior between interacting participants. An interesting problem worth considering concerns choreography realizability enforcement, while ensuring a resilient evolution upon facing changes. The strategy that we adopt to solve this problem is twofold: given a BPMN2 choreography specification and a set of existing services discovered as possible participants, (i) adapt their interaction protocol to the choreography roles and (ii) coordinate their (adapted) interaction so to fulfill the global collaboration prescribed by the choreography. This paper proposes a synthesis approach able to automatically generate, out of a BPMN2 choreography specification, the needed adaptation and coordination logic, and distribute it between the participants so to enforce the choreography. Our approach supports choreography evolution through adaptation to possible changes in the discovered services, while still keeping the prescribed coordination.

Towards Recovering the Software Architecture of Microservice-Based Systems

Today the microservice architectural style is being adopted by many key technological players such as Netflix, Amazon, The Guardian. A microservice architecture is composed of a large set of small services, each running in its own process and communicating with lightweight mechanisms (often via REST APIs). If on one side having a large set of independently developed services helps in terms of developer productivity, scalability, maintainability, on the other side it is very difficult to have a clear understanding of the overall architecture of a microservice-based software system, specially when the deployment and operation of the involved microservices evolves at run-time. In this paper we present MicroART, an architecture recovery approach for microservice-based systems. By using Model-Driven Engineering techniques, we leverage a suitably defined domain-specific language for representing the key aspects of the architecture of a microservice-based system and provide a tool-chain for automatically extracting architecture models of the system. The only inputs of MicroART are: (i) a GitHub repository containing the source code of the system and (ii) a reference to the container engine managing it. We validated MicroART on a publicly available benchmark system, with promising results.

MicroART: A Software Architecture Recovery Tool for Maintaining Microservice-Based Systems

Microservice-based systems are characterised by a multitude of small services, each running in its own process and communicating with lightweight mechanisms. The microservice architectural style strongly encourages high decoupling among microservices in order to ease their independent deployment, operation, and maintenance. However, there are situations in which having a global overview of the system is fundamental. In this paper we present the first prototype of our Architecture Recovery Tool for microservice-based systems called MicroART. MicroART following Model-Driven Engineering principles, is able to generate models of the software architecture of a microservice-based system, that can be managed by software architects for multiple purposes.

CHOReOSynt: enforcing choreography realizability in the future internet

Choreographies are an emergent Service Engineering (SE) approach to compose together and coordinate services in a distributed way. A choreography formalizes the way business participants coordinate their interactions. The focus is not on orchestrations of the work performed within them, but rather on the exchange of messages between these participants. The problems usually addressed when considering a choreography-based specification of the system to be realized are realizability check, and conformance check. In this paper we describe the CHOReOSynt tool, which has been conceived to deal with an additional problem, namely, automated choreography enforcement. That is, when the goal is to actually realize a service choreography by reusing third-party services, their uncontrolled (or wrongly coordinated) composite behavior may show undesired interactions that preclude the choreography realization. CHOReOSynt solves this problem by automatically synthesizing additional software entities that, when interposed among the services, allow for preventing undesired interactions. Screencast: http://choreos.disim.univaq.it/downloads/

Model-driven adaptation of service choreographies

Service choreographies represent a powerful and flexible approach to compose software services in a fully distributed way. A key enabler for the actual realization of choreographies is the ability to automatically compose services, and perform exogenous coordination and adaptation of their interaction. This is a nontrivial and error prone task. Automatic support for realizing choreographies is needed. In this paper we focus on adapter generation and describe our novel approach to the synthesis of service Adapters. When needed, adapters permit to correctly bind concrete services to (abstract) choreography roles by solving possible protocol mismatches. Enterprise Integration Patterns are used as adaptation primitives and composed to realize complex adaptation policies.

User-centric Android flexible permissions

Privacy in mobile apps is a fundamental aspect to be considered, particularly with regard to meeting end user expectations. Due to the rigidities of the Android permission model, desirable trade-offs are not allowed. End users are confined into a secondary role, having the only option of choosing between either privacy or functionalities. This work proposes a user-centric approach to the flexible management of Android permissions that empowers end users to specify the desired level of permissions on a per-feature basis.

Composition of Advanced (\mu )Services for the Next Generation of the Internet of Things

In recent years, technologies such as Machine to Machine (M2M) and the Internet of Things (IoT) have become core technologies of tomorrow’s world that probably we will go to inhabit. Potentially, everything that belongs to the environment around us is or will be connected, and it will produce data or provide services of some kind. The big penetration of technologies such as sensors, electronic tags, micro-controllers, etc., and the inexorable growth of the Internet, improve the understanding of the physical environment, from industrial buildings or the workplace, up to the farmland. The proliferation of all these devices, often able to host in a very small footprint, an entire TCP/IP stack, has meant that the M2M world was incorporated into the world IoT establishing an environment where things and people are able to communicate, share information and generate knowledge.

On the model-driven synthesis of evolvable service choreographies

Choreographies are a form of decentralized composition that model the external interaction of the participant services by specifying peer-to-peer message exchanges from a global perspective. When mismatching third-party services are to be composed, obtaining the distributed coordination and adaptation logic required to suitably realize a choreography is a non-trivial and error prone task. Automatic support is then needed. Nowadays, very few approaches address the problem of actually realizing choreographies in an automatic way. In this paper, we share the experience we had in two EU projects specifically targeted at choreographies, and report on a novel model-driven approach to the automatic synthesis of evolving choreographies we are currently working on. We illustrate our method at work on a use case in the domain of Smart Mobility & Tourism.

Biological Immunity and Software Resilience: Two Faces of the Same Coin?

Biological systems modeling and simulation is an important stream of research for both biologists and computer scientists. On the one hand, biologists ask for systemic approaches to model biological systems to the purpose of simulating them on a computer and predicting their behavior, which is resilient by nature. This would limit as much as possible the number of experiments in laboratory, which are known to be expensive, often impracticable, hardly reproducible, and slow. On the other hand, beyond facing the development challenges related to the achievement of the resilience to be offered by biological system simulators, computer scientists ask for a well-established engineering methodology to systematically deal with the peculiarities of software resilient systems, in their more general sense. In line with this, in this paper we report on our preliminary study of immune systems a particular kind of biological systems aimed at devising software abstractions that enable the systematic modeling of resilient systems and their automated treatment. We propose a bio-inspired concept architecture for structuring resilient systems based on the Akka implementation of the widely-known Actor Model, which supports scalable and resilient concurrent computation. To the best of our knowledge, this work represents a first preliminary step towards devising a bio-inspired paradigm for engineering the development of resilient software systems.