Marco Guazzone | Università degli Studi del Piemonte Orientale (original) (raw)

articles by Marco Guazzone

Research paper thumbnail of Forensic analysis of the ChatSecure instant messaging application on android smartphones

Abstract We present the forensic analysis of the artifacts generated on Android smartphones by Ch... more Abstract We present the forensic analysis of the artifacts generated on Android smartphones by ChatSecure, a secure Instant Messaging application that provides strong encryption for transmitted and locally-stored data to ensure the privacy of its users. We show that ChatSecure stores local copies of both exchanged messages and files into two distinct, AES-256 encrypted databases, and we devise a technique able to decrypt them when the secret passphrase, chosen by the user as the initial step of the encryption process, is known. Furthermore, we show how this passphrase can be identified and extracted from the volatile memory of the device, where it persists for the entire execution of ChatSecure after having been entered by the user, thus allowing one to carry out decryption even if the passphrase is not revealed by the user. Finally, we discuss how to analyze and correlate the data stored in the databases used by ChatSecure to identify the \{IM\} accounts used by the user and his/her buddies to communicate, as well as to reconstruct the chronology and contents of the messages and files that have been exchanged among them. For our study we devise and use an experimental methodology, based on the use of emulated devices, that provides a very high degree of reproducibility of the results, and we validate the results it yields against those obtained from real smartphones.

Research paper thumbnail of The ShareGrid Peer-to-Peer Desktop Grid: Infrastructure, Applications, and Performance Evaluation

Peer-to-Peer (P2P) Desktop Grids are computing infrastructures that aggregate a set of desktop-cl... more Peer-to-Peer (P2P) Desktop Grids are computing infrastructures that aggregate a set of desktop-class machines in which all the participating entities have the same roles, responsibilities, and rights. In this paper, we present ShareGrid, a P2P Desktop Grid infrastructure based on the OurGrid middleware, that federates the resources provided by a set of small research laboratories to easily share and use their computing resources. We discuss the techniques and tools we employed to ensure scalability, efficiency, and usability, and describe the various applications used on it. We also demonstrate the ability of ShareGrid of providing good performance and scalability by reporting the results of experimental evaluations carried out by running various applications with different resource requirements. Our experience with ShareGrid indicates that P2P Desktop Grids can represent an effective answer to the computing needs of small research laboratories, as long as they provide both ease of management and use, and good scalability and performance.

Research paper thumbnail of FC2Q: Exploiting Fuzzy Control in Server Consolidation for Cloud Applications with SLA Constraints

Research paper thumbnail of Maximizing Profit in Green Cellular Networks through Collaborative Games

Federations among sets of Cloud Providers (CPs), whereby a set of CPs agree to mutually use their... more Federations among sets of Cloud Providers (CPs), whereby a set of CPs agree to mutually use their own resources to run the VMs of other CPs, are considered a promising solution to the problem of reducing the energy cost. In this paper, we address the problem of federation formation for a set of CPs, whose solution is necessary to exploit the potential of cloud federations for the reduction of the energy bill. We devise an algorithm, based on cooperative game theory, that can be readily implemented in a distributed fashion, and that allows a set of CPs to cooperatively set up their federations in such a way that their individual profit is increased with respect to the case in which they work in isolation. We show that, by using our algorithm and the proposed CPs' utility function, they are able to self-organize into Nash-stable federations and, by means of iterated executions, to adapt themselves to environmental changes. Numerical results are presented to demonstrate the effectiveness of the proposed algorithm.

inproceedings by Marco Guazzone

Research paper thumbnail of Peer-to-Peer Desktop Grids in the Real World: The ShareGrid Project

ShareGrid is a peer-to-peer desktop grid aimed at satisfying the computing needs of the small res... more ShareGrid is a peer-to-peer desktop grid aimed at satisfying the computing needs of the small research laboratories located in the Piedmont area in Northern Italy. ShareGrid adopts a cooperative approach, in which each participant allows the other ones to use his/her own resources on a reciprocity basis. ShareGrid is based on the OurGrid middleware, that provides a set of mechanisms enabling participating entities to quickly, fairly, and securely share their resources. In this paper we report our experience in designing, deploying, and using ShareGrid, and we describe the applications using it, as well as the lessons we learned, the problems that still remain open, and some possible solutions to them.

Research paper thumbnail of Energy-Efficient Resource Management for Cloud Computing Infrastructures

Cloud computing is growing in popularity among computing paradigms for its appealing property of ... more Cloud computing is growing in popularity among computing paradigms for its appealing property of considering "Everything as a Service". The goal of a Cloud infrastructure provider is to maximize its profit by minimizing the amount of violations of Quality-of-Service (QoS) levels agreed with service providers, and, at the same time, by lowering infrastructure costs. Among these costs, the energy consumption induced by the Cloud infrastructure, for running Cloud services, plays a primary role. Unfortunately, the minimization of QoS violations and, at the same time, the reduction of energy consumption is a conflicting and challenging problem. In this paper, we propose a framework to automatically manage computing resources of Cloud infrastructures in order to simultaneously achieve suitable QoS levels and to reduce as much as possible the amount of energy used for providing services. We show, through simulation, that our approach is able to dynamically adapt to time-varying workloads (without any prior knowledge) and to significantly reduce QoS violations and energy consumption with respect to traditional static approaches.

Research paper thumbnail of Exploiting VM Migration for the Automated Power and Performance Management of Green Cloud Computing Systems

Cloud computing is an emerging computing paradigm in which “Everything is as a Service”, includin... more Cloud computing is an emerging computing paradigm in which “Everything is as a Service”, including the provision of virtualized computing infrastructures (known as Infrastructure-as-a-Service modality) hosted on the physical infrastructure, owned by an infrastructure provider. The goal of this infrastructure provider is to maximize its profit by minimizing the amount of violations of Quality-of-Service (QoS) levels agreed with its customers and, at the same time, by lowering infrastructure costs among which energy consumption plays a major role. In this paper, we propose a framework able to automatically manage resources of cloud infrastructures in order to simultaneously achieve suitable QoS levels and to reduce as much as possible the amount of energy used for providing services. We show, through simulation, that our approach is able to dynamically adapt to time-varying workloads (without any prior knowledge) and to significantly reduce QoS violations and energy consumption with respect to traditional static approaches.

Research paper thumbnail of Fuzzy-Q&E: Achieving QoS Guarantees and Energy Savings for Cloud Applications with Fuzzy Control

We address the problem of managing cloud applications, consisting of a set of virtual machines (V... more We address the problem of managing cloud applications, consisting of a set of virtual machines (VMs), characterized by bursty and dynamic workloads, in such a way to provide guarantees on their Quality-of-Services (QoS) and, at the same time, to minimize the energy consumption of the physical infrastructure running them. We propose a fuzzy controller, Fuzzy-Q& E, that is able to allocate to the VMs of each cloud application the minimum amount of physical capacity needed to meet its QoS requirements. In this way, the number of physical resources that must be switched-on at any given time is reduced with respect to the case in which physical machines are statically provisioned and, consequently, less energy is required to run a given cloud workload. We implement a prototype of our controller on a Xen-based testbed, and we perform a set of experiments using an E-Commerce benchmark in which we compare Fuzzy-Q&E against Dyna QoS, a state-of-the-art fuzzy controller for virtualized resources. Experimental results show that Fuzzy-Q&E out performs Dyna QoS both in terms of the ability of meeting the QoS level of the application, and of the amount of physical capacity allocated to each VM.

Research paper thumbnail of A Game-Theoretic Approach to Coalition Formation in Green Cloud Federations

Federations among sets of Cloud Providers (CPs), whereby a set of CPs agree to mutually use their... more Federations among sets of Cloud Providers (CPs), whereby a set of CPs agree to mutually use their own resources to run the VMs of other CPs, are considered a promising solution to the problem of reducing the energy cost. In this paper, we address the problem of federation formation for a set of CPs, whose solution is necessary to exploit the potential of cloud federations for the reduction of the energy bill. We devise an algorithm, based on cooperative game theory, that can be readily implemented in a distributed fashion, and that allows a set of CPs to cooperatively set up their federations in such a way that their individual profit is increased with respect to the case in which they work in isolation. We show that, by using our algorithm and the proposed CPs' utility function, they are able to self-organize into Nash-stable federations and, by means of iterated executions, to adapt themselves to environmental changes. Numerical results are presented to demonstrate the effectiveness of the proposed algorithm.

phdtheses by Marco Guazzone

Research paper thumbnail of Power and Performance Management in Cloud Computing Systems

masterstheses by Marco Guazzone

Research paper thumbnail of Caratterizzazione del Carico per Sistemi Grid

Papers by Marco Guazzone

Research paper thumbnail of Enabling the forensic study of application-level encrypted data in Android via a Frida-based decryption framework

Proceedings of the 18th International Conference on Availability, Reliability and Security

Research paper thumbnail of Towards Action + State Process Model Discovery

Process model discovery covers different methodologies to mine a process model from traces of pro... more Process model discovery covers different methodologies to mine a process model from traces of process executions, and is gaining an important role in Artificial Intelligence research. Current approaches in the area, with few exceptions, focus on determining a model of the flow of actions only. However, in several contexts, (i) restricting the attention to actions is quite limitative, since the effects of such actions have to be analysed, too, and (ii) traces provide additional pieces of information, in the form of states (i.e., values of parameters possibly affected by the actions): for instance, in several medical domains traces include both actions and measurements of patients’ parameters. In this paper, we propose AS-SIM (Action-State SIM), the first approach able to mine a process model which comprehends two distinct classes of nodes, to capture both actions and states.

Research paper thumbnail of Integrating ISA and Part-of Domain Knowledge into Process Model Discovery

Future Internet, Nov 28, 2022

Research paper thumbnail of WQR-Ud

Proceedings of the 12th EAI International Conference on Performance Evaluation Methodologies and Tools, 2019

FemtoClouds are computing platforms, implementing the Fog Computing paradigm, consisting in an en... more FemtoClouds are computing platforms, implementing the Fog Computing paradigm, consisting in an ensemble of heterogeneous mobile devices whose users agree to run the tasks offloaded by other users. FemtoClouds are well suited for the execution of Bag-of-Tasks (BoTs) applications, but, being characterized by high resource heterogeneity and volatility, require the availability of scheduling techniques able to effectively deal with ensembles of independently-owned, heterogeneous devices that can suddenly leave the system. In this paper we propose WQR-UD, an online scheduling algorithm that, thanks to the combination of simple task and device selection policies (that do not require any information concerning the applications and the devices) with effective heterogeneity and volatility tolerance mechanisms, is able to effectively schedule a stream of BoT applications on FemtoCloud systems. We assess the ability of WQR-UD to meet its design goals by running an extensive simulation study for a large set of realistic operational scenarios. Our results clearly indicate that WQR-UD is able to effectively schedule a stream of BoT applications on FemtoCloud systems.

Research paper thumbnail of The TAAROA Project Specification

Since its introduction, the Grid computing paradigm has been widely adopted both in scientific an... more Since its introduction, the Grid computing paradigm has been widely adopted both in scientific and also in industrial areas. The main advantage of the Grid computing paradigm is the ability to enable, in a transparent way, the sharing and the coordination of several heterogeneous and large-scale distributed resources belonging to different institutional domains. One of its limitation is the lack of facilities for executing services. In fact, Grid computing has been traditionally used and improved for running computational-intensive or data-intensive applications. A service differs from this kind of applications in that it usually waits for requests from clients and replies with useful information; moreover, a service is typically subjected to some predefined constraints, called Service Level Agreement (SLA), including both temporal and performance restrictions. In this paper we present the TAAROA middleware, a software system that tries to extend the traditional target of the Grid c...

Research paper thumbnail of Temporal reasoning and query answering with preferences and probabilities for medical decision support

Expert Systems with Applications, 2022

Research paper thumbnail of Online User-driven Task Scheduling for FemtoClouds

2019 Fourth International Conference on Fog and Mobile Edge Computing (FMEC), 2019

In Fog Computing, FemtoClouds are emerging computing systems consisting of a set of heterogeneous... more In Fog Computing, FemtoClouds are emerging computing systems consisting of a set of heterogeneous mobile devices whose users allow to run tasks offloaded by other users. FemtoClouds are well suited to run Bag-of-Tasks (BoTs) applications, but they need effective scheduling algorithms that are able to deal with collections of independently-owned, heterogeneous devices that can suddenly leave the system. In this paper, we present UDFS, an online scheduling algorithm that, by combining knowledge-free task and device selection policies with suitable heterogeneity and volatility tolerance mechanisms, can effectively schedule a stream of BoT applications on FemtoClouds. We evaluate the ability of UDFS to achieve its design goals and to perform better than existing scheduling alternatives, by carrying out a thorough simulation study for a large set of realistic scenarios. Our results indeed show that UDFS can effectively schedule a stream of BoT applications on FemtoClouds, and it can do so more effectively than existing scheduling alternatives.

Research paper thumbnail of GREEN 2017 Committee GREEN Steering Committee

Research paper thumbnail of An educational toolkit for teaching cloud computing

ACM SIGCOMM Computer Communication Review, 2021

In an educational context, experimenting with a real cloud computing platform is very important t... more In an educational context, experimenting with a real cloud computing platform is very important to let students understand the core concepts, methodologies and technologies of cloud computing. However, API heterogeneity of cloud providers complicates the experimentation by forcing students to focus on the use of different APIs, and by hindering the jointly use of different platforms. In this paper, we present EasyCloud, a toolkit enabling the easy and effective use of different cloud platforms. In particular, we describe its features, architecture, scalability, and use in our cloud computing courses, as well as the pedagogical insights we learnt over the years.

Research paper thumbnail of Forensic analysis of the ChatSecure instant messaging application on android smartphones

Abstract We present the forensic analysis of the artifacts generated on Android smartphones by Ch... more Abstract We present the forensic analysis of the artifacts generated on Android smartphones by ChatSecure, a secure Instant Messaging application that provides strong encryption for transmitted and locally-stored data to ensure the privacy of its users. We show that ChatSecure stores local copies of both exchanged messages and files into two distinct, AES-256 encrypted databases, and we devise a technique able to decrypt them when the secret passphrase, chosen by the user as the initial step of the encryption process, is known. Furthermore, we show how this passphrase can be identified and extracted from the volatile memory of the device, where it persists for the entire execution of ChatSecure after having been entered by the user, thus allowing one to carry out decryption even if the passphrase is not revealed by the user. Finally, we discuss how to analyze and correlate the data stored in the databases used by ChatSecure to identify the \{IM\} accounts used by the user and his/her buddies to communicate, as well as to reconstruct the chronology and contents of the messages and files that have been exchanged among them. For our study we devise and use an experimental methodology, based on the use of emulated devices, that provides a very high degree of reproducibility of the results, and we validate the results it yields against those obtained from real smartphones.

Research paper thumbnail of The ShareGrid Peer-to-Peer Desktop Grid: Infrastructure, Applications, and Performance Evaluation

Peer-to-Peer (P2P) Desktop Grids are computing infrastructures that aggregate a set of desktop-cl... more Peer-to-Peer (P2P) Desktop Grids are computing infrastructures that aggregate a set of desktop-class machines in which all the participating entities have the same roles, responsibilities, and rights. In this paper, we present ShareGrid, a P2P Desktop Grid infrastructure based on the OurGrid middleware, that federates the resources provided by a set of small research laboratories to easily share and use their computing resources. We discuss the techniques and tools we employed to ensure scalability, efficiency, and usability, and describe the various applications used on it. We also demonstrate the ability of ShareGrid of providing good performance and scalability by reporting the results of experimental evaluations carried out by running various applications with different resource requirements. Our experience with ShareGrid indicates that P2P Desktop Grids can represent an effective answer to the computing needs of small research laboratories, as long as they provide both ease of management and use, and good scalability and performance.

Research paper thumbnail of FC2Q: Exploiting Fuzzy Control in Server Consolidation for Cloud Applications with SLA Constraints

Research paper thumbnail of Maximizing Profit in Green Cellular Networks through Collaborative Games

Federations among sets of Cloud Providers (CPs), whereby a set of CPs agree to mutually use their... more Federations among sets of Cloud Providers (CPs), whereby a set of CPs agree to mutually use their own resources to run the VMs of other CPs, are considered a promising solution to the problem of reducing the energy cost. In this paper, we address the problem of federation formation for a set of CPs, whose solution is necessary to exploit the potential of cloud federations for the reduction of the energy bill. We devise an algorithm, based on cooperative game theory, that can be readily implemented in a distributed fashion, and that allows a set of CPs to cooperatively set up their federations in such a way that their individual profit is increased with respect to the case in which they work in isolation. We show that, by using our algorithm and the proposed CPs' utility function, they are able to self-organize into Nash-stable federations and, by means of iterated executions, to adapt themselves to environmental changes. Numerical results are presented to demonstrate the effectiveness of the proposed algorithm.

Research paper thumbnail of Peer-to-Peer Desktop Grids in the Real World: The ShareGrid Project

ShareGrid is a peer-to-peer desktop grid aimed at satisfying the computing needs of the small res... more ShareGrid is a peer-to-peer desktop grid aimed at satisfying the computing needs of the small research laboratories located in the Piedmont area in Northern Italy. ShareGrid adopts a cooperative approach, in which each participant allows the other ones to use his/her own resources on a reciprocity basis. ShareGrid is based on the OurGrid middleware, that provides a set of mechanisms enabling participating entities to quickly, fairly, and securely share their resources. In this paper we report our experience in designing, deploying, and using ShareGrid, and we describe the applications using it, as well as the lessons we learned, the problems that still remain open, and some possible solutions to them.

Research paper thumbnail of Energy-Efficient Resource Management for Cloud Computing Infrastructures

Cloud computing is growing in popularity among computing paradigms for its appealing property of ... more Cloud computing is growing in popularity among computing paradigms for its appealing property of considering "Everything as a Service". The goal of a Cloud infrastructure provider is to maximize its profit by minimizing the amount of violations of Quality-of-Service (QoS) levels agreed with service providers, and, at the same time, by lowering infrastructure costs. Among these costs, the energy consumption induced by the Cloud infrastructure, for running Cloud services, plays a primary role. Unfortunately, the minimization of QoS violations and, at the same time, the reduction of energy consumption is a conflicting and challenging problem. In this paper, we propose a framework to automatically manage computing resources of Cloud infrastructures in order to simultaneously achieve suitable QoS levels and to reduce as much as possible the amount of energy used for providing services. We show, through simulation, that our approach is able to dynamically adapt to time-varying workloads (without any prior knowledge) and to significantly reduce QoS violations and energy consumption with respect to traditional static approaches.

Research paper thumbnail of Exploiting VM Migration for the Automated Power and Performance Management of Green Cloud Computing Systems

Cloud computing is an emerging computing paradigm in which “Everything is as a Service”, includin... more Cloud computing is an emerging computing paradigm in which “Everything is as a Service”, including the provision of virtualized computing infrastructures (known as Infrastructure-as-a-Service modality) hosted on the physical infrastructure, owned by an infrastructure provider. The goal of this infrastructure provider is to maximize its profit by minimizing the amount of violations of Quality-of-Service (QoS) levels agreed with its customers and, at the same time, by lowering infrastructure costs among which energy consumption plays a major role. In this paper, we propose a framework able to automatically manage resources of cloud infrastructures in order to simultaneously achieve suitable QoS levels and to reduce as much as possible the amount of energy used for providing services. We show, through simulation, that our approach is able to dynamically adapt to time-varying workloads (without any prior knowledge) and to significantly reduce QoS violations and energy consumption with respect to traditional static approaches.

Research paper thumbnail of Fuzzy-Q&E: Achieving QoS Guarantees and Energy Savings for Cloud Applications with Fuzzy Control

We address the problem of managing cloud applications, consisting of a set of virtual machines (V... more We address the problem of managing cloud applications, consisting of a set of virtual machines (VMs), characterized by bursty and dynamic workloads, in such a way to provide guarantees on their Quality-of-Services (QoS) and, at the same time, to minimize the energy consumption of the physical infrastructure running them. We propose a fuzzy controller, Fuzzy-Q& E, that is able to allocate to the VMs of each cloud application the minimum amount of physical capacity needed to meet its QoS requirements. In this way, the number of physical resources that must be switched-on at any given time is reduced with respect to the case in which physical machines are statically provisioned and, consequently, less energy is required to run a given cloud workload. We implement a prototype of our controller on a Xen-based testbed, and we perform a set of experiments using an E-Commerce benchmark in which we compare Fuzzy-Q&E against Dyna QoS, a state-of-the-art fuzzy controller for virtualized resources. Experimental results show that Fuzzy-Q&E out performs Dyna QoS both in terms of the ability of meeting the QoS level of the application, and of the amount of physical capacity allocated to each VM.

Research paper thumbnail of A Game-Theoretic Approach to Coalition Formation in Green Cloud Federations

Federations among sets of Cloud Providers (CPs), whereby a set of CPs agree to mutually use their... more Federations among sets of Cloud Providers (CPs), whereby a set of CPs agree to mutually use their own resources to run the VMs of other CPs, are considered a promising solution to the problem of reducing the energy cost. In this paper, we address the problem of federation formation for a set of CPs, whose solution is necessary to exploit the potential of cloud federations for the reduction of the energy bill. We devise an algorithm, based on cooperative game theory, that can be readily implemented in a distributed fashion, and that allows a set of CPs to cooperatively set up their federations in such a way that their individual profit is increased with respect to the case in which they work in isolation. We show that, by using our algorithm and the proposed CPs' utility function, they are able to self-organize into Nash-stable federations and, by means of iterated executions, to adapt themselves to environmental changes. Numerical results are presented to demonstrate the effectiveness of the proposed algorithm.

Research paper thumbnail of Enabling the forensic study of application-level encrypted data in Android via a Frida-based decryption framework

Proceedings of the 18th International Conference on Availability, Reliability and Security

Research paper thumbnail of Towards Action + State Process Model Discovery

Process model discovery covers different methodologies to mine a process model from traces of pro... more Process model discovery covers different methodologies to mine a process model from traces of process executions, and is gaining an important role in Artificial Intelligence research. Current approaches in the area, with few exceptions, focus on determining a model of the flow of actions only. However, in several contexts, (i) restricting the attention to actions is quite limitative, since the effects of such actions have to be analysed, too, and (ii) traces provide additional pieces of information, in the form of states (i.e., values of parameters possibly affected by the actions): for instance, in several medical domains traces include both actions and measurements of patients’ parameters. In this paper, we propose AS-SIM (Action-State SIM), the first approach able to mine a process model which comprehends two distinct classes of nodes, to capture both actions and states.

Research paper thumbnail of Integrating ISA and Part-of Domain Knowledge into Process Model Discovery

Future Internet, Nov 28, 2022

Research paper thumbnail of WQR-Ud

Proceedings of the 12th EAI International Conference on Performance Evaluation Methodologies and Tools, 2019

FemtoClouds are computing platforms, implementing the Fog Computing paradigm, consisting in an en... more FemtoClouds are computing platforms, implementing the Fog Computing paradigm, consisting in an ensemble of heterogeneous mobile devices whose users agree to run the tasks offloaded by other users. FemtoClouds are well suited for the execution of Bag-of-Tasks (BoTs) applications, but, being characterized by high resource heterogeneity and volatility, require the availability of scheduling techniques able to effectively deal with ensembles of independently-owned, heterogeneous devices that can suddenly leave the system. In this paper we propose WQR-UD, an online scheduling algorithm that, thanks to the combination of simple task and device selection policies (that do not require any information concerning the applications and the devices) with effective heterogeneity and volatility tolerance mechanisms, is able to effectively schedule a stream of BoT applications on FemtoCloud systems. We assess the ability of WQR-UD to meet its design goals by running an extensive simulation study for a large set of realistic operational scenarios. Our results clearly indicate that WQR-UD is able to effectively schedule a stream of BoT applications on FemtoCloud systems.

Research paper thumbnail of The TAAROA Project Specification

Since its introduction, the Grid computing paradigm has been widely adopted both in scientific an... more Since its introduction, the Grid computing paradigm has been widely adopted both in scientific and also in industrial areas. The main advantage of the Grid computing paradigm is the ability to enable, in a transparent way, the sharing and the coordination of several heterogeneous and large-scale distributed resources belonging to different institutional domains. One of its limitation is the lack of facilities for executing services. In fact, Grid computing has been traditionally used and improved for running computational-intensive or data-intensive applications. A service differs from this kind of applications in that it usually waits for requests from clients and replies with useful information; moreover, a service is typically subjected to some predefined constraints, called Service Level Agreement (SLA), including both temporal and performance restrictions. In this paper we present the TAAROA middleware, a software system that tries to extend the traditional target of the Grid c...

Research paper thumbnail of Temporal reasoning and query answering with preferences and probabilities for medical decision support

Expert Systems with Applications, 2022

Research paper thumbnail of Online User-driven Task Scheduling for FemtoClouds

2019 Fourth International Conference on Fog and Mobile Edge Computing (FMEC), 2019

In Fog Computing, FemtoClouds are emerging computing systems consisting of a set of heterogeneous... more In Fog Computing, FemtoClouds are emerging computing systems consisting of a set of heterogeneous mobile devices whose users allow to run tasks offloaded by other users. FemtoClouds are well suited to run Bag-of-Tasks (BoTs) applications, but they need effective scheduling algorithms that are able to deal with collections of independently-owned, heterogeneous devices that can suddenly leave the system. In this paper, we present UDFS, an online scheduling algorithm that, by combining knowledge-free task and device selection policies with suitable heterogeneity and volatility tolerance mechanisms, can effectively schedule a stream of BoT applications on FemtoClouds. We evaluate the ability of UDFS to achieve its design goals and to perform better than existing scheduling alternatives, by carrying out a thorough simulation study for a large set of realistic scenarios. Our results indeed show that UDFS can effectively schedule a stream of BoT applications on FemtoClouds, and it can do so more effectively than existing scheduling alternatives.

Research paper thumbnail of GREEN 2017 Committee GREEN Steering Committee

Research paper thumbnail of An educational toolkit for teaching cloud computing

ACM SIGCOMM Computer Communication Review, 2021

In an educational context, experimenting with a real cloud computing platform is very important t... more In an educational context, experimenting with a real cloud computing platform is very important to let students understand the core concepts, methodologies and technologies of cloud computing. However, API heterogeneity of cloud providers complicates the experimentation by forcing students to focus on the use of different APIs, and by hindering the jointly use of different platforms. In this paper, we present EasyCloud, a toolkit enabling the easy and effective use of different cloud platforms. In particular, we describe its features, architecture, scalability, and use in our cloud computing courses, as well as the pedagogical insights we learnt over the years.

Research paper thumbnail of Power and Performance Management in Cloud Computing Systems

Cloud computing is an emerging computing paradigm which is gaining popularity in IT industry for ... more Cloud computing is an emerging computing paradigm which is gaining popularity in IT industry for its appealing property of considering “Everything as a Service”. The goal of a cloud infrastructure provider is to maximize its profit by minimizing the amount of violations of Quality-of-Service (QoS) levels agreed with service providers, and, at the same time, by lowering infrastructure costs. Among these costs, the energy consumption induced by the cloud infrastructure, for running cloud services, plays a primary role. Unfortunately, the minimization of QoS violations and, at the same time, the reduction of energy consumption is a conflicting and challenging problem. In this thesis, we propose a framework to automatically manage computing resources of cloud infrastructures in order to simultaneously achieve suitable QoS levels and to reduce as much as possible the amount of energy used for providing services. We show, through simulation, that our approach is able to dynamically adapt ...

Research paper thumbnail of Caratterizzazione del Carico per Sistemi Grid

Research paper thumbnail of EasyCloud: a Rule based Toolkit for Multi-platform Cloud/Edge Service Management

2020 Fifth International Conference on Fog and Mobile Edge Computing (FMEC), 2020

Research paper thumbnail of EasyCloud: Multi-clouds made easy

2021 IEEE 45th Annual Computers, Software, and Applications Conference (COMPSAC), 2021

Interoperability between different cloud platforms is a critical requirement for letting users to... more Interoperability between different cloud platforms is a critical requirement for letting users to smoothly switch between different cloud providers and combine their services. However, the lack of standard interfaces to access these cloud platforms may result in the vendor lock-in situation, whereby users are locked into a specific cloud provider. In this paper, we present EasyCloud, a toolkit able to effectively support the creation and usage of Multi-cloud Systems (MSs) by providing interoperability, platform independence, effective resource provisioning, and ease of use. We describe its architecture and implementation, and experimentally assess the performance of EasyCloud, and compare it to existing alternative MS toolkits that are representative of the state-of-the-art. Our results clearly show that EasyCloud is highly scalable, quite efficient, and outperforms the other alternative toolkits.

Research paper thumbnail of User action representation and automated reasoning for the forensic analysis of mobile devices

The 16th International Conference on Availability, Reliability and Security, 2021

Research paper thumbnail of Profit-aware Resource Management for Edge Computing Systems

Proceedings of the 1st International Workshop on Edge Systems, Analytics and Networking, 2018

Research paper thumbnail of Profit‐aware coalition formation in fog computing providers: A game‐theoretic approach

Concurrency and Computation: Practice and Experience, 2019

SummaryWe consider fog computing scenarios where data generated by a set of IoT applications need... more SummaryWe consider fog computing scenarios where data generated by a set of IoT applications need to be processed locally by a set of fog nodes, belonging to distinct Fog Infrastructure Providers (FIPs) sharing the same co‐location facility, with the aim of increasing their profits. This is a challenging goal as it requires reducing costs and meeting QoS targets despite time‐varying workloads. We argue that these FIPs may find it profitable to cooperate by mutually sharing their workload and resources, and we show (by using a game‐theoretical framework) that this is indeed the case when stable coalitions can be formed. Based on these results, in this paper, we present (1) a mathematical model for maximizing the profit obtained for allocating IoT applications to a group of FIPs, and (2) a coalition formation algorithm that allows each FIP to decide with whom to cooperate so as to increment its profits. The efficacy of the devised algorithm is assessed by means of an experimental eval...

Research paper thumbnail of Technical Solutions for Legal Challenges: Equality of Arms in Criminal Proceedings

Global Jurist, 2020

The paper focuses on how computational models and methods impact on current legal systems, and in... more The paper focuses on how computational models and methods impact on current legal systems, and in particular, on criminal justice. While the discussion about the suitabilty of the exploitation of learning machines and Artificial Intelligence (AI) either as surveillance means and human substitutes in the judicial decision-making process is arising, the authors reflect upon the risk of using AI and algorithm-based evidence in criminal proceedings. The claim of the paper is twofold: on the one hand, we should reinterpret todays legal frameworks, e. g. the European Convention of Human Rights, shifting the attention from possible violations of the right to privacy to potential infringements on a basic fair trial feature, the Equality of Arms. On the other hand, we should aknowledge that main legal issues, triggered by the breathtaking advancements in AI, can properly be addressed mainly through technical solutions (e. g. methods for assessing the completeness and correctness of digital e...

Research paper thumbnail of The Android Forensics Automator (AnForA): A tool for the Automated Forensic Analysis of Android Applications

Computers & Security, 2019

Research paper thumbnail of Prometheus: A flexible toolkit for the experimentation with virtualized infrastructures

Concurrency and Computation: Practice and Experience, 2017

Research paper thumbnail of Forensic analysis of Telegram Messenger on Android smartphones

Digital Investigation, 2017