Michele Stecca

A Platform for Smart Object Virtualization and Composition

One of the most challenging objectives of the Internet of Things (IoT) domain is the identification of interaction paradigms and communication standards to integrate smart objects (SOs), i.e., physical objects able to interact with the network. Such interaction paradigms and communication protocols belong to what can be called the IoT application layer, on which this paper focuses. This paper presents app execution platform (AEP), a platform that supports the design, deployment, execution, and management of IoT applications in the domain of smart home, smart car, and smart city. AEP was designed to coherently fulfill a set of requirements covered only partially or in a fragmented way by other IoT application platforms. AEP focuses on SO virtualization and on composite application (CA) orchestration and supports dynamic object availability.

An Architecture for a Mashup Container in Virtualized Environments

This paper presents the architecture and the organization of a Mashup Container that supports the deployment and the execution of Event Driven Mashups (i.e., Composite Services in which the Services interact through events rather than through the classical Call-Response paradigm) following the Platform as a Service model in the Cloud Computing paradigm. We describe the two main modules of the container, namely the Deployment Module and the Service Execution Platform, and focus our attention on the performance on of the latter. In particular we discuss the results of an evaluation test that we run in a virtualized environment (VMware based) supporting scalability and fault tolerance.

An execution platform for event driven mashups

This paper presents a Service Execution Platform for Event Driven service compositions (a.k.a. Mashups), typically used in Telco services, and more in general applicable in domains characterized by a working principle based on asynchronous events. The platform reference model is based on an orchestration system and on a set of service proxies hosted in the Service Execution Platform. The orchestration system executes Mashup sessions, i.e., instances of service compositions activated by external events, by coordinating the actions of the service proxies and takes care of load balancing, security (AAA), and fault tolerance. The paper presents the software architecture of the platform and shows how Web Service technology can be used to support event based communication and how session-less orchestration provides support for scalability and fault tolerance. Finally the paper presents a prototype implementation of the platform and a set of experimental results.

Smart Object Cooperation through Service Composition

We consider the coordination of smart objects interacting in physical environments. We show that it is possible to re-use the concepts related to the Service Composition paradigm to support the coordination of smart objects such as for example household electrical appliances, sensors, actuators, smartphones, etc. We show that applications involving smart object interaction can be seen as a particular case of event driven composite services. As a consequence a platform supporting smart object interaction can be obtained by including additional components to an event driven service orchestration platform. In this paper we describe a platform for smart object interaction based on a platform for event driven service orchestration enriched with two additional components, namely a Presence Server component, to manage smart object availability, and a Universal Gateway, to support smart object interoperability.

Always-on distributed spreadsheet mashups

We present a platform that supports the creation of distributed data Mashups, implemented through the composition of multiple spreadsheets. The basic idea is to link cell ranges belonging to different spreadsheets in such a way to come up with a distributed spreadsheet. While such a behavior is already supported in private file spaces, our platform extends the operating principle and the functionality to the Internet in a secure way, using a SOA infrastructure as a communication bus. The platform consists of a client component, installed as a Plug-in in spreadsheet applications, and of a server component, accessible as a Web Service, that orchestrates the data exchanges among the client spreadsheets. One of the most original functionalities provided by the platform and described in the paper is that of guaranteeing the propagation of values along chains of linked spreadsheets even when some of the component spreadsheets are off-line. In addition to the description of the platform the paper also includes the description of a Spreadsheet Mashup framework specifically suited to hierarchical organizations such as those of enterprises. The architecture of the framework is presented in the light of a real-life example.

Sticky Session Support in Auto Scaling IaaS Systems

We analyze the issues related to the management of sessions in Web Applications running on Auto Scaling IaaS systems. We focus on the effect of scaling operations (i.e., dynamic addition/removal of virtual machines) on the Sticky Session paradigm provided by Web Servers. We propose two different solutions, namely Session Monitoring and Session Migration, and describe the implementation of the former in the Open Source Eucalyptus IaaS system.

Analysis of design patterns for composite telco services

The adoption of IT-based interfaces to monitor and control telco capabilities is a consolidated approach. In such a scenario the end-users design composite services that orchestrate functions implemented through one or more resources managed by telecom operators. In addition to the issues that have to be faced to support the design of composite services in general, in this case it is also necessary to face issues that are specific to the telco domain. In fact, telco services strongly rely on the processing of asynchronous events generated by resources; moreover, they usually handle large and dynamic sets of concurrent processes that execute long-running transactions each of which includes interactions between the composite service and the telco capabilities. The complexity of the telco domain suggests to define a set of patterns to ease the development of composite services. The goal of this paper is to propose such patterns and to show how they can be implemented both as plain Java objects and as BPEL processes. The pattern based approach is illustrated by means of a service which takes advantage of the combined use of multiple patterns. Moreover, the paper suggests some improvements on the definition of the interfaces and on the reference model for the development of composite services.

Mashup Patterns from Service Component Taxonomy

In this paper we focus on the structure and on the application of Server Side Mashups, that is of composite services executed and orchestrated in managed platforms. Unlike Client Side Mashups, which run in client platforms under direct user control, Server Side Mashups may run in background and do not require direct user control, thus enabling a set of applications which are not supported by Client Side Mashups. In particular we consider the case of Internet/Telco Server Side Mashups, that is of Server Side Mashups that combine services coming both from the Internet domain and from the telecom operator domain. We first propose a taxonomy for the services that may be combined to build Server Side Mashups. The taxonomy is based both on the functionality and on the type of user-service interaction of the services considered. Then we list some of the most relevant application environments in which Server Side Mashups can be profitably used thanks to the increasing number of available services, both over the telecom operator networks and over the Internet. Finally we propose a set of patterns to be used as a reference by Server Side Mashup developers. For each pattern we provide real life examples based on the experience gained during the OPUCE Project [1].

Towards a CAPEX-free service delivery platform

The paper is aiming at analyzing the possibility for a telecommunication operator to decrease the fixed costs of service delivery, by reducing CapEx (Capital Expenditures) and transforming part of them into OpEx (Operational Expenditures). In particular, the paper analyses the advantages and the risks of moving a service platform on a cloud-based infrastructure, and investigates the impacts of adopting Open Source Software (OSS) solutions for deploying components of a Service Delivery Platform (SDP) and for delivering new services. The proposed approach is exemplified by means of an experimental case study, in which an OSS orchestration engine is deployed on virtual resources dynamically allocated by a cloud infrastructure.

A comparison between Web Service and JAVA Message Service technologies for Event-Driven Mashup execution

This paper presents a Service Execution Platform (SEP) for Event-Driven service compositions (a.k.a. Mashups), typically used in domains characterised by a working principle based on asynchronous events. The platform reference model is based on an orchestration system and on a set of Service Proxies (SPs) hosted in the SEP. The orchestration system executes Mashup Sessions by coordinating the actions of the SPs, and takes care of load balancing, security (AAA) and fault tolerance. The paper presents and compares two versions of the SEP based on two different technologies, namely Web Services (WSs) and JAVA Message Service (JMS).