Main page Research activities Publications Talks Hobby and spare time Write me Last updated on
15 April 2014

Recommended publications

Among my publications hereby enumerated, let me particularly recommend the following readings:

Filed patents

  1. T. Cucinotta, F. Chang, R. Viswanathan. "Exploiting Probabilistic Latency Expressions For Placing Cloud Applications," Filed US Patent 14/075727. November 2013.

  2. T. Cucinotta, I. Bedini. "Method, Processing Framework, Aggregator And Computer Program Product For Processing Data," Filed European Patent 13360033. October 2013.

  3. T. Cucinotta, Stéphane Betgé-Brezetz. "Method and system for controlling the exchange of Privacy-Sensitive Information," Filed European Patent 13360029. September 2013.

  4. T. Cucinotta. "Method and System for Graphical User Interface Layout Generation, Computer Program Product," Filed European Patent 13360015. August 2013.

  5. E. Jul, D. Cherubini, T. Cucinotta. "Secure Data Processing," Filed European Patent 13306038. July 2013.

  6. T. Cucinotta, A. Sala. "Methods and Devices for Protecting Private Data," Filed US Patent 13/944964. July 2013.

  7. T. Cucinotta, "Methods and Devices for Controlling Access to Distributed Resources," Filed US Patent 13/926832. June 2013.

  8. T. Cucinotta, Ivan Bedini. "Method for Data Processing, Element to Process Data, Method for Monitoring Activity and Computer Program Product," Filed European Patent 13360010. May 2013.

  9. T. Cucinotta. "Scheduling," Filed European Patent 13305397. March 2013.

  10. T. Cucinotta. "System Security," Filed European Patent 13305396. March 2013.

  11. I. Bedini, T. Cucinotta, A. Sala, B. Theeten. "Systems And Methods For Self-Adaptive Distributed Systems," Filed US Patent 13/853533. March 2013.

  12. T. Cucinotta, D. Cherubini, E. Jul. "Collaborative Uses of a Cloud Computing Confidential Domain of Execution," Filed US Patent 13/622007. September 2012.

  13. T. Cucinotta, D. Cherubini. "System Control," Filed European Patent 12360068. September 2012.

  14. T. Cucinotta, D. Cherubini, E. Jul. "Secure Data Processing," Filed European Patent 12360045. June 2012.

  15. T. Cucinotta, D. Cherubini, E. Jul. "Secure Data Processing," Filed European Patent 12360044. June 2012.

  16. T. Cucinotta. "Task Scheduling," Filed European Patent 12360037. May 2012

Publications

You can download a bibtex file with references for all of my publications. Check out the talks page as well.

Publications on international conference and workshop proceedings

  1. T. Cucinotta, D. Lugones, D. Cherubini, E. Jul. "Data Centre Optimisation Enhanced by Software Defined Networking," (to appear) in Proceedings of the 7th IEEE International Conference on Cloud Computing (IEEE CLOUD 2014), June 27 - July 2, 2014, Alaska, USA.

  2. T. Cucinotta, D. Lugones, D. Cherubini, K. Oberle. "Brokering SLAs for end-to-end QoS in Cloud Computing," in Proceedings of the 4th International Conference on Cloud Computing and Services Science (CLOSER 2014), April 3-5, 2014, Barcelona, Spain.

  3. T. Cucinotta, D. Cherubini, E. Jul. "Confidential Execution of Cloud Services," in Proceedings of the 4th International Conference on Cloud Computing and Services Science (CLOSER 2014), April 3-5, 2014, Barcelona, Spain.

  4. T. Cucinotta, K. Oberle, M. Stein, P. Domschitz, S. Mullender. "Run-time Support for Real-Time Multimedia in the Cloud," in Proceedings of the 2nd International Workshop on Real-Time and Distributed Computing in Emerging Applications (REACTION 2013), co-located with the 34th IEEE Real-Time Systems Symposium (RTSS 2013), December 3, 2013, Vancouver, Canada.

  5. K. Oberle, D. Cherubini, T. Cucinotta. "End-to-End Service Quality for Cloud Applications," in Proceedings of the 10th International Conference on Economics of Grids, Clouds, Systems and Services (GECON 2013), September 18-20, 2013, Zaragoza, Spain.

  6. T. Cucinotta. "Priority Inheritance on Condition Variables," in Proceedings of the 9th International Workshop on Operating Systems Platforms for Embedded Real-Time applications (OSPERT 2013), July 9th, 2013, Paris, France. Abstract

    In this paper, a mechanism is presented to deal with priority inversion in real-time systems when multiple threads of execution synchronize with each other by means of mutual exclusion semaphores coupled with the programming abstraction of condition variables. Traditional priority inheritance solutions focus on addressing priority or deadline inversion as due to the attempt to lock mutual exclusion semaphores, or deal exclusively with specific interaction patterns such as client-server ones. The mechanism proposed in this paper allows the programmer to explicitly declare to the run-time environment what tasks are able to perform a notify operation on a condition over which other tasks may be suspended through a wait operation. This enables developers of custom interaction models for real-time tasks to exploit their knowledge of the application-specific interaction so as to potentially reduce priority inversion. The paper discusses issues in the realization of the technique, and its integration with existing priority inheritance mechanisms on nowadays operating systems. Also, the paper briefly presents the prototyping of the technique within the open-source RTSim real-time systems simulator, which is used to highlight the potential advantages of the exposed technique through a simple simulated scenario.

  7. T. Cucinotta, A. Santogidis. "CloudNetSim - Simulation of Real-Time Cloud Computing Applications," in Proceedings of the 4th International Workshop on Analysis Tools and Methodologies for Embedded and Real-time Systems (WATERS 2013), July 9th, 2013, Paris, France. Abstract

    In this paper, we describe CloudNetSim, a project aiming to realise a simulation platform supporting our ongoing and planned research activities in the area of resource management and scheduling for distributed QoS-sensitive and soft real-time applications. It is based on OMNeT++, integrating in the platform a set of modules for the simulation of CPU scheduling, including hierarchical scheduling at both levels of the hypervisor and guest Operating System, as needed when simulating cloud infrastructures. Thanks to the modularity of OMNeT++, CloudNetSim may easily leverage many existing simulation models already available for networking, including standard network components and protocols, such as TCP/IP. After a brief overview of related simulation tools found in the literature, and the discussion of their limitations, we provide a detailed description of the internals of our simulator. Then, we show results gathered from a few representative scenarios demonstrating how its behaviour matches with the one of simple real applications.

  8. T. Cucinotta, N. Redini. "Access Control for the Pepys Internet-Wide File-System," in Proceedings of the 7th International Workshop on Plan 9 (IWP9 2012), November 14-16 2012, Dublin, Ireland. Abstract

    This paper describes the Access Control Model realized for the novel Pepys distributed, Internet-wide, file-system. The model design has been widely inspired to various existing standards and best practices about access control and security in file-system access, but it also echoes peculiar basic principles characterizing the design of Pepys, as well as the πP protocol, over which Pepys itself relies. The paper also provides technical details about how the model has been realized on a Linux port of Pepys.

  9. K. Konstanteli, T. Cucinotta, K. Psychas, T. Varvarigou. "Admission Control for Elastic Cloud Services," in Proceedings of the 5th IEEE International Conference on Cloud Computing (IEEE CLOUD 2012), June 24-29 2012, Honolulu, Hawaii, USA. Abstract

    This paper presents an admission control test for deciding whether or not it is worth to admit a set of services into a Cloud, and in case of acceptance, obtain the optimum allocation for each of the components that comprise the services. In the proposed model, the focus is on hosting elastic services the resource requirements of which may dynamically grow and shrink, depending on the dynamically varying number of users and patterns of requests. In finding the optimum allocation, the presented admission control test uses an optimization model, which incorporates business rules in terms of trust, eco-efficiency and cost, and also takes into account affinity rules the components that comprise the service may have. The proposed approach also allows for partial acceptance of a service and possible federation with other Cloud providers. By incorporating a probabilistic approach that relies on the actual probabilities of requiring extra elastic computing and networking capacity for the services at runtime, the model reduces the physical resources that need to be booked for elasticity reasons by promoting the allocation of more services on already used physical hosts. The output of the admission control test is the set of accepted services, and the allocated computing and networking capacity for the components that comprise them on the selected physical hosts and subnets. The problem was modeled on the General Algebraic Modeling System (GAMS) and solved under realistic provider’s settings that demostrate the efficiency of the proposed method.

  10. K. Konstanteli, T. Cucinotta, T. Varvarigou. "Probabilistic Admission Control for Elastic Cloud Computing," in Proceedings of the IEEE International Conference on Service-Oriented Computing and Applications (SOCA 2011), December 12-14 2011, Irvine, CA. Abstract

    Focusing on elasticity, this paper tackles the problem of optimum allocation of elastic services on virtualized physical resources by incorporating a probabilistic approach in terms of availability guarantees. The proposed approach relies on the actual probabilities of needing extra computational requirements during runtime, which are incorporated into the admission control test, allowing for reducing the number of physical computational resources that need to be booked for elasticity reasons. The output of the optimization problem is the set of the admitted services, as well as the allocated computing capacity for each service component that comprise them on the physical hosts that have been selected in the optimal allocation pattern. The resulting optimization problem constitutes a probabilistic admission control test that also allows for proper trade-offs among business level objectives in terms of trust, eco-efficiency and cost, depending on their relative sensitivity as considered by the Cloud provider. The problem was modeled on the General Algebraic Modeling System (GAMS) and solved under realistic provider’s settings that demostrate the efficiency of the proposed method.

  11. T. Cucinotta, G. Anastasi. "A Heuristic for Optimum Allocation of Real-Time Service Workflows," in Proceedings of the IEEE International Conference on Service-Oriented Computing and Applications (SOCA 2011), December 12-14 2011, Irvine, CA. Abstract

    In this paper, the problem of optimum allocation of real-time service workflows over a set of heterogeneous resources is tackled. In previous works, this problem was formally stated in terms of a Mixed-Integer Non-Linear Programming optimization program, that could be solved by recurring to commercial solvers. However, due to the big dimension of the solution space to be searched, finding the absolutely optimum solution: might take too much time in order to be concretely useful; it may preclude the use of these techniques in large-scale infrastructures; it makes the technique hardly usable adaptively in response to corrective actions that may be needed when some bad event occurs while the services are running (e.g., hardware-level failures). Therefore, in this paper a heuristic algorithm based on graph-matching is introduced that may find very efficiently a reasonably good, albeit non-necessarily optimum, solution. The algorithm is described, and its performance assessed by a set of synthetic experiments.

  12. L. Abeni and T. Cucinotta, "Efficient Virtualisation of Real-Time Activities," in Proceedings of the IEEE International Workshop on Real-Time Service-Oriented Architecture and Applications (RTSOAA 2011), December 12-14 2011, Irvine, CA. Abstract

    Reservation-based scheduling has been proved to be an effective solution for serving virtual machines when some kind of real-time guarantees are required. However, the virtualisation mechanism and the algorithm used for implementing CPU reservations might have a large impact on the guarantees provided to tasks running inside the VMs. This paper presents an experimental evaluation of some different solutions, showing the different trade-offs and the advantages of using more advanced scheduling algorithms.

  13. G. F. Anastasi, T. Cucinotta, G. Lipari, M. García-Valls, "A QoS Registry for Adaptive Real-Time Service-Oriented Applications," in Proceedings of the IEEE International Workshop on Real-Time Service-Oriented Architecture and Applications (RTSOAA 2011), December 12-14 2011, Irvine, CA. Abstract

    Real-time service-oriented applications are charac- terized by Quality of Service (QoS) requirements that cannot be properly managed by using classical real-time systems methodologies. In dynamic environments the QoS management can effectively leverage adaptive techniques, that provide flexibility and do not require a complex offline analysis. In turn, such techniques make a massive use of on-line collected data regarding the application performance and the resource requirements. Moreover, a common issue for adaptive systems is the one of deciding the initial configuration of the application and/or the run-time environment at the time of service instantiation. In this paper, we propose a QoS registry for coping with these issues and supporting the configuration of proper scheduling parameters in real-time Service Oriented Architectures (SOAs). The registry permits to gather QoS data related to different functional behaviors of applications, to predict the future trend based on data already collected and to permanently store such data for an effective reuse at the time of future re-instantiations. We have also built an implementation of such registry, computed its overhead costs and performed some experiments for showing the effectiveness in auto-tuning resource allocations for providing QoS guarantees in a real-time SOA.

  14. T. Cucinotta and V. Subramanian. "Characterization and analysis of pipelined applications on the Intel SCC," in Proceedings of the 4th Symposium of the Many-core Applications Research Community (MARC 2011), Potsdam, Germany, December 2011. Abstract

    Many-core computing platforms can be used to parallelize computations by dividing the data to be processed into smaller chunks and processing them simultaneously on different cores. One possible approach in such parallelization is to set up a pipeline such that each smaller chunk of data passes in turn through all the processors involved. In this paper we examine some approaches to set up such a pipeline on the Intel SCC. We use a combination of the message passing and the shared memory capability of the SCC hardware through the interfaces provided by the RCCE library for our implementation. We build a model to analyze and compare the performance of such pipelines by measuring the total time for computation. This model is used to illustrate the effects of type of memory scheme used, ordering of cores in the pipeline and caching.

  15. T. Cucinotta. "Optimum Scalability Point for Parallelisable Real-Time Components," in Proceedings of the International Workshop on Synthesis and Optimization Methods for Real-time and Embedded Systems (SOMRES 2011), co-located with the 32nd IEEE Real-Time Systems Symposium (RTSS 2011), Vienna, Austria, November 29 - December 2, 2011. Abstract

    Distributing the workload of computationally intensive software components across a set of homogeneous computing resources (nodes, hosts, processors, cores), for the purpose of allowing them to meet precise timing (response-time) constraints, is often a pain due to the difficulties in understanding how the software will actually scale. Often, such a problem is faced by recurring to a trial-and-error process. In this paper, a methodology is introduced to tackle the problem of finding the optimum number of processors for deploying parallelisable real-time software components. Basic building blocks of the methodology are: a generic performance model for the response-time of a parallel software component; a concrete procedure for tuning optimally the parameters of the model; the application of optimisation techniques that allow to compute what is the minimum allocation needed to meet precise deadline constraints, as well as the one that minimises the response-time; the consideration of multiple real-time (independent) components to be deployed on the same multi/many-core hardware.

  16. T. Cucinotta, S. Gogouvitis, K. Konstanteli. "SLAs in Virtualized Cloud Computing Infrastructures with QoS Assurance," in Proceedings of the International Workshop on eContracting in the Clouds, co-located with the eChallenges 2011 Conference, Florence, Italy, October 27th 2011. Abstract

    Cloud Computing is gaining momentum as one of the technologies that promises to subvert our own idea of computing. With an increasing usage of cloud applications and their consequent dependency from connectivity, the nowadays Personal Computer is becoming merely a mobile device acting as a front-end to on-line applications and services. This huge paradigm shift in computing is witnessed for example by big market players who announced the imminent launch of innovative products and Operating Systems (like Chrome notebooks and the accompanying Chrome OS2. by Google), which are capable of projecting the user into the network in a few seconds by booting and starting immediately a web browser and (mostly) nothing else. In such a challenging scenario, more and more of the applications that we traditionally used locally on our PC are being hosted on cloud infrastructures and operated remotely through the Internet. This includes not only batch tasks, but also interactive applications which need to operate inherently with good levels of responsiveness. In this paper, the challenging problem is discussed of how to ensure predictable levels of Quality of Service (QoS) to cloud applications across the multiple layers of a typical cloud infrastructure, and how a reasonable Service Level Agreement (SLA) management and enforcement policy might look like. The scope of this paper represents a hands-on experience that was gained by the authors realising the IRMOS real-time cloud-computing infrastructure in the context of the IRMOS European Project.

  17. T. Cucinotta, F. Checconi, D. Giani. "Improving Responsiveness for Virtualized Networking Under Intensive Computing Workloads," in Proceedings of the 13th Real-Time Linux Workshop (RTLWS 2011), Prague, Czech Republic, October 2011. Abstract

    In this paper the problem of providing network response guarantees to multiple Virtual Machines (VMs) co-scheduled on the same set of CPUs is tackled, where the VMs may have to host both responsive real-time applications and batch compute-intensive workloads. When trying to use a real-time reservation- based CPU scheduler for providing stable performance guarantees to such a VM, the compute-intensive workload would be scheduled better with high time granularities, to increase performance and reduce system overheads, whilst the real-time workload would need lower time granularities in order to keep the response-time under acceptable levels. The mechanism that is proposed in this paper mixes both concepts, allowing the scheduler to dynamically switch between fine-grain and coarse-grain scheduling intervals depending on whether the VM is performing network operations or not. A prototype implementation of the proposed mechanism has been realized for the KVM hypervisor when running on Linux, modifying a deadline-based real-time scheduling strategy for the Linux kernel developed previously. The gathered experimental results show that the proposed technique is effective in controlling the response-times of the real-time workload inside a VM while at the same time it allows for an efficient execution of the batch compute-intensive workload.

  18. J. Lelli, G. Lipari, D. Faggioli, T. Cucinotta, "An efficient and scalable implementation of global EDF in Linux," Proceedings of the 7th International Workshop on Operating Systems Platforms for Embedded Real-Time Applications (OSPERT 2011), Porto, Portugal, July 2011. Abstract

    The increasing popularity of multi-core architectures is pushing researchers and developers to consider multi-cores for executing soft and hard real-time applications. Real-Time schedulers for multi processor systems can be roughly categorized into partitioned and global schedulers. The first ones are more adequate for hard real-time embedded systems, in which applications are statically loaded at start-up and rarely change at run-time. Thanks to automatic load balancing, global schedulers may be useful in open systems, where applications can join and leave the system at any time, and for applications with highly varying workloads.
    Linux supports global and partitioned scheduling through its real-time scheduling class, which provides SCHED_FIFO and SCHED_RR fixed priority policies. Recently, the SCHED_DEADLINE policy was proposed that provides Earliest Deadline First scheduling with budget control. In this paper we propose a new implementation for global EDF scheduling which uses a heap global data structure to speed-up scheduling decisions. We also compare the execution time of the main scheduling functions in the kernel for four different implementations of global scheduling, showing that our implementation is as scalable and efficient as SCHED_FIFO.

  19. T. Cucinotta, D. Faggioli, G. Bagnoli, "Low-Latency Audio on Linux by Means of Real-Time Scheduling," Proceedings of the Linux Audio Conference (LAC 2011), Maynooth, Ireland, May 2011.

  20. S. Kumar, T. Cucinotta, G. Lipari, "A Latency Simulator for Many-core Systems," in Proceedings of the 44th Annual Simulation Symposium (ANSS 2011), part of the Spring Simulation Multiconference (SpringSim'11). Abstract

    In this paper we present MCoreSim, an open-source simulation framework for massively parallel and many-core com- puting systems based on OMNeT++. The simulator supports tile-based architectures with distributed memory and mesh-based interconnects. Its primary purpose is to allow for in- vestigations on the impact of the heterogeneous in-chip communication latencies, as arising due to the network-on-a-chip structure of future and emerging many-core processors, on the performance of the hosted applications. We plan to use MCoreSim to study the variety of possible choices in realizing a suitable software stack for these systems, especially in terms of the choices at the kernel design level.

  21. T. Cucinotta, F. Checconi, G. Kousiouris, D. Kyriazis, T. Varvarigou, A. Mazzetti, Z. Zlatev, J. Papay, M. Boniface, S. Berger, D. Lamp, T. Voith, M. Stein, "Virtualised e-Learning with Real-Time Guarantees on the IRMOS Platform," in Proceedings of the IEEE International Conference on Service-Oriented Computing and Applications (SOCA 2010), Perth, Australia, December 2010. Best Paper Award!

  22. D. Kyriazis, A. Menychtas, G. Kousiouris, K. Oberle, T. Voith, M. Boniface, E. Oliveros, T. Cucinotta, S. Berger, "A Real-time Service Oriented Infrastructure," in Proceedings of the Annual International Conference on Real-Time and Embedded Systems (RTES 2010), Singapore, November 2010. Abstract

    The advancements in distributed computing have driven the emergence of service-based infrastructures that allow for on-demand provision of ICT assets. Taking into consideration the complexity of distributed environments, significant challenges exist in providing and managing the offered on-demand resources with the required level of Quality of Service (QoS), especially for real-time interactive and streaming applications. In this paper we propose an approach for providing real-time QoS guarantees by enhancing service oriented infrastructures with coherent and consistent real-time attributes at various levels (application, network, storage, processing). The approach considers the full lifecycle of service-based systems including service engineering, Service Level Agreement (SLA) negotiation and management, service provisioning and monitoring. QoS parameters at application, platform and infrastructure levels are given specific attention as the basis for provisioning policies in the context of temporal constraints.

  23. T. Cucinotta, D. Giani, D. Faggioli, F. Checconi, "Effective Real-Time Computing on Linux," in Proceedings of the 12th Real-Time Linux Workshop (RTLWS 2010), Nairobi, Kenya, October 2010. Abstract

    In this paper we present an architecture design for supporting real time computing on Linux. This architecture focuses on improving the usability of real time capabilities for applications by providing a unified Application Programming Interface. Applications can therefore use it without having to know exactly what the underlying scheduling algorithm is. Still, the real-time computing capabilities of the platform may be exploited to the maximum extent. The main aim of the paper is to gather feedback from the community about the design and directions for development.

  24. T. Cucinotta, D. Giani, D. Faggioli and F. Checconi, "Providing Performance Guarantees to Virtual Machines using Real-Time Scheduling," in Proceedings of the 5th Workshop on Virtualization and High-Performance Cloud Computing (VHPC 2010), Ischia (Naples), Italy, August 2010. Abstract

    In this paper we tackle the problem of providing Quality of Service guarantees to virtualized applications, focusing on computing and networking guarantees. We propose a mechanism for providing temporal isolation based on a CPU real time scheduling strategy. This allows not only to have control over the individual virtual machine throughput, but also on the activation latency and response-time by which virtualized software components react to external events. We show experimental results gathered on a real system validating the approach.

  25. T. Cucinotta, D. Faggioli, "An Exception Based Approach to Timing Constraints Violations in Real-Time and Multimedia Applications," in Proceedings of the IEEE Symposium on Industrial Embedded Systems (SIES 2010), Trento, Italy, July 2010. Abstract

    In this paper, an exception-based programming paradigm is envisioned to deal with timing constraints violations occurring in soft real-time and multimedia applications written in the C language. In order to prove viability of the approach, a mechanism allowing to use such paradigm has been designed and implemented as an open-source library of C macros making use of the standard POSIX API (a few Linux-specific optimizations are also briefly discussed). The envisioned approach has been validated by modifying mplayer, one of the most widely used multimedia player for Linux, so as to use the introduced library. Experimental results demonstrate how the exception-based paradigm is effective in improving the audio/video delay exhibited by the player.

  26. D. Faggioli, G. Lipari, T. Cucinotta, "The Multiprocessor BandWidth Inheritance Protocol," in Proceedings of the 22nd Euromicro Conference on Real-Time Systems (ECRTS 2010), Bruxelles, Belgium, July 2010. Abstract

    In this paper we present the Multiprocessor Bandwidth Inheritance (M-BWI) protocol, an extension of the Bandwidth Inheritance (BWI) protocol to symmetric multiprocessor and multicore systems. Similarly to priority inheritance, M-BWI reduces priority inversion in reservation-based scheduling systems; it allows the coexistence of hard, soft and non-real-time tasks; it does not require any information on the temporal parameters of the tasks; hence, it is particularly suitable to open systems, where tasks can dynamically arrive and leave, and their temporal parameters are unknown or only partially known. Moreover, if it is possible to estimate such parameters as the worst-case execution time and the critical sections length, then it is possible to compute an upper bound to the task blocking time. Finally, the M-BWI protocol is neutral to the underlying scheduling scheme, since it can be implemented both in global and partitioned scheduling schemes.

  27. T. Cucinotta, F. Checconi, L. Abeni, L. Palopoli, "Self-tuning Schedulers for Legacy Real-Time Applications," in Proceedings of the 5th ACM European Conference on Computer Systems (EuroSys 2010), Paris, France, April 2010. Abstract

    We present an approach for adaptive scheduling of soft realtime legacy applications (for which no timing information is exposed to the system). Our strategy is based on the combination of two techniques: 1) a real-time monitor that observes the sequence of events generated by the application to infer its activation period, 2) a feedback mechanism that adapts the scheduling parameters to ensure a timely execution of the application. By a thorough experimental evaluation of an implementation of our approach, we show its performance and its efficiency.

  28. T. Cucinotta, K. Konstanteli, T. Varvarigou, "Advance Reservations for Distributed Real-Time Workflows with Probabilistic Service Guarantees," in Proceedings of the IEEE International Conference on Service-Oriented Computing and Applications (SOCA 2009), Taipei, Taiwan, December 2009. Abstract

    This paper addresses the problem of optimum allocation of distributed real-time workflows with probabilistic service guarantees over a Grid of physical resources made available by a provider. The discussion focuses on how such a problem may be mathematically formalised, both in terms of constraints and objective function to be optimized, which also accounts for possible business rules for regulating the deployment of the workflows. The presented formal problem constitutes a probabilistic admission control test that may be run by a provider in order to decide whether or not it is worth to admit new workflows into the system, and to decide what the optimum allocation of the workflow to the available resources is. Various options are presented which may be plugged into the formal problem description, depending on the specific needs of individual workflows.

  29. T. Cucinotta, L. Abeni, L. Palopoli, F. Checconi, "The Wizard of OS: a Heartbeat for Legacy Multimedia Applications," in Proceedings of the 7th IEEE Workshop on Embedded Systems for Real-Time Multimedia (ESTImedia 2009), Grenoble, France, October 2009.

  30. T. Cucinotta, G. Lipari, L. Palopoli, L. Abeni, R. Santos, "Multi-level feedback control for Quality of Service Management," in Proceedings of the 14th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA 2009), Palma de Mallorca, Spain, September 2009. Abstract

    We consider the problem of power-aware Quality of Service (QoS) control for soft real-time embedded systems. Applications can have time-varying and scarcely known resource requirements, and can be activated and terminated at any time. However, they have the capability to switch among a discrete set of operation modes with different QoS levels and resource requirements. In addition, the platform provides resources with power-scaling capabilities and may be subject to power constraints. We present a QoS control architecture achieving optimum trade-offs between overall QoS and power consumption of the system, based on two nested control loops. The external one decides dynamically the optimum configuration for the system, in terms of application QoS modes and resource power modes, while the internal one modulates the resource allocations on a job by job basis, so as to respect timing constraints. We demonstrate the effectiveness of the approach by extensive simulations with trace data of real multimedia applications.

  31. F. Checconi, T. Cucinotta, M. Stein, "Real-Time Issues in Live Migration of Virtual Machines," in Proceedings of the 4th Workshop on Virtualization and High-Performance Cloud Computing (VHPC 2009), Delft, The Netherlands, August 2009.

  32. T. Cucinotta, G. Anastasi, L. Abeni "Respecting temporal constraints in virtualised services," in Proceedings of the 2nd IEEE International Workshop on Real-Time Service-Oriented Architecture and Applications (RTSOAA 2009), Seattle, Washington, July 2009. Abstract

    This paper reports some experiences in providing service guarantees to real-time (RT) applications running in a Virtual Machine (VM), showing how proper scheduling is a necessary condition for a predictable execution. In particular, resource reservation techniques allow to cope with some of the overhead and unpredictabilities experienced when executing multiple VMs on the same host.

  33. K. Konstanteli, D. Kyriazis, T. Varvarigou, T. Cucinotta, G. Anastasi, "Real-time guarantees in flexible advance reservations," in Proceedings of the 2nd IEEE International Workshop on Real-Time Service-Oriented Architecture and Applications (RTSOAA 2009), Seattle, Washington, July 2009. Abstract

    This paper deals with the problem of scheduling workflow applications with Quality of Service (QoS) constraints, comprising real-time and interactivity constraints, over a serviceoriented Grid network. A novel approach is proposed, in which high-level Advance Reservations, supporting flexible start and end time, are combined with low-level soft real-time scheduling, allowing for the concurrent deployment of multiple services on the same host while fulfilling their QoS requirements. By undertaking a stochastic approach, in which a-priori knowledge is leveraged about the probability of activation of the application workflows within the reserved time-frame, the proposed methodology allows for the achievement of various trade-offs between the need for respecting QoS constraints (user perspective) and the need for having good resource saturation levels (service provider perspective).

  34. F. Checconi, T. Cucinotta, D. Faggioli, G. Lipari, "Hierarchical Multiprocessor CPU Reservations for the Linux Kernel," in Proceedings of the 5th International Workshop on Operating Systems Platforms for Embedded Real-Time Applications (OSPERT 2009), Dublin, Ireland, June 2009. Abstract

    This paper presents ongoing work in the development of a scheduling framework that will improve the service guarantees for soft real-time applications deployed on Linux. The scheduler has been designed around the current kernel infrastructure, trying to keep the changes minimal, and basing the scheduling policy on strong theoretical results. The main goal is to achieve hierarchical distribution of the available computing power on multiprocessor platforms, avoiding alterations to the existing user interfaces. The proposed framework exploits the hierarchical arrangement of tasks within groups and subgroups that is already possible within the Linux kernel. However, it adds the capability for each group to be assigned a precise fraction of the computing power available on all the processors, using existing uni-processor resource reservation techniques. Tasks are scheduled globally within each single group, and the partitions assigned to each group need not to be static, but can be dynamically balanced. Furthermore, the proposed mechanism can be used to support a variety of possible partitioning schemes using processor affinities.

  35. T. Cucinotta, D. Faggioli, A. Evangelista, "Exception-Based Management of Timing Constraints Violations for Soft Real-Time Applications," in Proceedings of the 5th International Workshop on Operating Systems Platforms for Embedded Real-Time Applications (OSPERT 2009), Dublin, Ireland, June 2009. Abstract

    This paper presents an open-source library for the C language supporting the specification and management of timing constraints within embedded soft real-time applications. The library provides a set of well-designed C macros that allow developers to associate timing constraints to code segments, and to deal with their violations through the wellestablished practise of exception-based management. After a brief overview of the requirements motivating the work, the exceptions library is presented. Then, the paper focuses on the specific macros that deal with the specification of deadline and execution-time constraints, with a few notes on how the library has been implemented. Finally, a few experimental results are shown in order to discuss the features and limitations of this approach, with the current implementation (on Linux) that relies almost completely on POSIX-compliant system calls.

  36. T. Cucinotta, G. Anastasi, L. Abeni, "Real-Time Virtual Machines," in Proceedings of the 29th Real-Time System Symposium (RTSS 2008) -- Work in Progress Session, Barcelona, December 2008. Abstract

    This paper tackles the problem of guaranteeing appropriate timeliness guarantees to real-time applications running in a virtualised Operating System. Preliminary experimental results are presented, highlighting how the appropriate use of well-established real-time scheduling strategies may be effective in facing with this challenging issue.

  37. T. Cucinotta, L. Abeni, S. K. Baruah, G. Lipari, L. Palopoli, "Weighted Feedback Reclaiming for Multimedia Applications," in Proceedings of the 6th IEEE Workshop on Embedded Systems for Real-Time Multimedia (ESTImedia 2008), Atlanta, Georgia, United States, October 2008. Abstract

    Resource reservations are a very popular choice to schedule multimedia tasks. However, the high variability of the resource requirements hinders a static choice of the scheduling parameters. In this paper we address this problem by a combination of two strategies: adaptive reservations and resource reclaiming. The first one operates "locally" (using the information of a single task), the second one operates "globally" distributing unused bandwidth between the tasks. In this paper, we show by analytical results and by extensive simulations that the two techniques can be safely and usefully combined.

  38. D. Faggioli, G. Lipari, T. Cucinotta, "An Efficient Implementation of the BandWidth Inheritance Protocol for Handling Hard and Soft Real-Time Applications in the Linux Kernel," in Proceedings of the 4th International Workshop on Operating Systems Platforms for Embedded Real-Time Applications (OSPERT 2008), Prague, Czech Republic, July 2008. Abstract

    This paper presents an improvement of the Bandwidth Inheritance Protocol, the natural extension of the well-known Priority Inheritance Protocol to resource reservation schedulers. The modified protocol allows for a better management of nested critical section, removes unneeded overheads in the management of task block and unblock events, and introduces a run-time deadlock detection mechanism at no cost. Also, an implementation of the new protocol on the Linux kernel is presented, along with experimental results gathered while running a synthetic application load. We show the introduced overhead is low and negligible for the applications of interest.

  39. T. Cucinotta "Access Control for Adaptive Reservations on Multi-User Systems," in Proceedings of the 14th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2008), St. Louis, MO, United States, April 2008.

  40. T. Cucinotta, L. Palopoli, "Feedback scheduling for pipelines of tasks," in Proceedings of the 10th International Conference on Hybrid Systems: Computation and Control (HSCC 2007), Pisa, Italy, April 2007. Abstract

    The problem analysed in this paper is how to effectively share a pool of resources amongst software applications consisting of pipelines of communicating tasks. The goal is to guarantee that specified Quality of Service (QoS) requirements are met. To this end, we advocate the use of a scheduling mechanism able to reserve fraction of the different resources to the competing tasks. Our work is focused on a feedback controlled adaptation of these fractions based on measurements of the QoS experienced by the application.

  41. T. Cucinotta, L. Palopoli, L. Marzario, A. Mancina, P. Valente, "A unified framework for managing different resources with QoS guarantees," in Proceedings of the 1st International Workshop on Operating System Platforms for Embedded Real-Time Applications (OSPERT 2005), Palma de Mallorca, Balearic Islands, Spain, July 2005. Abstract

    This paper describes ongoing research activities aimed at developing a unified framework by which a general purpose operative system is able to support applications with Quality of Service requirements. The work is focused on a feedback based dynamic management of the resources required by an application, where each resource is handled through the use of a Resource Reservation paradigm. This allows applications to share the access to a resource by specifying the fraction of usage, where such fractions are dynamically adapted by the system on the basis of observations made on the hosted activities. Research in this area comprises development of both a theoretical framework for modelling applications and analysing the impact of control theoretic feedback strategies to the QoS experienced by applications, and a prototype implementation of an architecture with the ability of providing the needed functionality on a Linux Operative System.

  42. T. Cucinotta, Di M. Di Natale, D. Corcoran, "Breaking down architectural gaps in smart-card middleware design," in Proceedings of the 1st International Conference on Trust and Privacy in Digital Business (TrustBus 2004), Zaragoza (Spain), September 2004, Springer-Verlag Lecture Notes in Computer Science (LNCS) 3184

  43. T. Cucinotta, R. Brigo, M. Di Natale, "Hybrid fingerprint matching on programmable smart cards," in Proceedings of the 1st International Conference on Trust and Privacy in Digital Business (TrustBus 2004), Zaragoza (Spain), September 2004, Springer-Verlag Lecture Notes in Computer Science (LNCS) 3184

  44. T. Cucinotta, L. Palopoli, L. Marzario, G. Lipari, L. Abeni, "Adaptive reservations in a Linux environment," Proceedings of the 10th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2004), Toronto, Canada, May 2004

  45. T. Cucinotta, D. Corcoran, M. Di Natale, "A protocol for programmable smart cards," Trust and Privacy in Digital Business Workshop, Prague, Czech Republic, September 2003. In proceedings of the 14th International Workshop on Database and Expert Systems Applications (DEXA 2003), IEEE Computer Society

  46. T. Cucinotta, M. Di Natale, S. Kolachalam, "A Modular Open Source Architecture for ICT Services in the Public Administration," in Proceedings of the 2nd EGOV Conference, Prague, Czech Republic, September 2003, Lecture Notes in Computer Science Serires, Vol. 2739

  47. T. Cucinotta, G. Cecchetti, G. Ferraro, "Adopting redundancy techniques for multicast stream authentication," in Proceedings of the 9th IEEE Workshop on Future Trends of Distributed Computing Systems (FTDCS 2003), Puerto Rico, May 2003, IEEE Computer Society

  48. T. Cucinotta, L. Palopoli, L. Marzario, "Stochastic feedback-based control of QoS in soft real-time systems," in Proceedings of the 43rd IEEE Conference on Decision and Control (CDC 2004), Bahamas, December 2004. Abstract

    This paper investigates application of feedback based control mechanisms to the problem of scheduling soft real-time tasks on a shared CPU. Each task has an execution time stochastically varying in time and it has to be provided with a specified level of Quality of Service (QoS). The problem of feedback control is formalised in the stochastic domain, by expressing QoS requirements in terms of properties to be satisfied by the stochastic process describing the evolution of the system state. We present several control schemes and address the fundamental problem of stochastic stability. Experimental results collected by a modified version of the Linux operating system show the effectiveness of the approach and its practical feasibility.

  49. L. Palopoli, T. Cucinotta, A. Bicchi, "Quality of service control for soft real-time applications," in Proceedings of the 42nd IEEE Conference on Decision and Control (CDC 2003), Hawaii, USA, December 2003. Abstract

    In this paper we present results obtained in the context of Quality of Service (QoS) control for soft real-time applications. The discussion addresses the issue of dynamically adjusting the bandwidth for a set of periodic tasks, when a reservation-based (RB) CPU scheduling policy is used. RB techniques are particularly suitable for this kind of applications since they allow an accurate mathematical modelling of the dynamic evolution of the QoS experienced by tasks. Based on this model, a control policy guaranteeing specified QoS levels for different tasks is illustrated, along with necessary and sufficient conditions for its existence. Moreover, the problem of steering a task QoS back into its nominal level is tackled, in response to deviations due to temporary overload conditions. Simulation results are reported, for the purpose of validating the approach.

Publications on international journals

  1. T. Cucinotta, D. Cherubini, E. Jul. "Confidential Domains of Execution," (to appear) in Bell Labs Technical Journal.

  2. B. Theeten, I. Bedini, P. Cogan, A. Sala, T. Cucinotta, "Towards the Optimization of a Parallel Streaming Engine for Telco Applications," in Bell Labs Technical Journal, Vol. 18, Issue 4, pp. 181-197, March 2014.

  3. T. Cucinotta, F. Checconi, L. Abeni, L. Palopoli, "Adaptive Real-Time Scheduling for Legacy Multimedia Applications," ACM Transactions on Embedded Computing Systems, Special Section on Embedded Systems for Real-Time Multimedia, Vol.11, No.4, December 2012. Abstract

    Multimedia applications are often executed on standard Personal Computers. The absence of established standards has hindered the adoption of real-time scheduling solutions in this class of applications. Developers have adopted a wide range of heuristic approaches to achieve an acceptable timing behaviour but the result is often unreliable. We propose a mechanism to extend the benefits of real-time scheduling to legacy applications based on the combination of two techniques: 1) a real-time monitor that observes and infers the activation period of the application, and 2) a feedback mechanism that adapts the scheduling parameters to improve its real-time performance.

  4. D. Faggioli, G. Lipari, T. Cucinotta. "Analysis and implementation of the multiprocessor bandwidth inheritance protocol," Springer Real-Time Systems Journal. September 2012. Abstract

    The Multiprocessor Bandwidth Inheritance (M-BWI) protocol is an extension of the Bandwidth Inheritance (BWI) protocol for symmetric multiprocessor systems. Similar to Priority Inheritance, M-BWI lets a task that has locked a resource execute in the resource reservations of the blocked tasks, thus reducing their blocking time. The protocol is particularly suitable for open systems where different kinds of tasks dynamically arrive and leave, because it guarantees temporal isolation among independent subsets of tasks without requiring any information on their temporal parameters. Additionally, if the temporal parameters of the interacting tasks are known, it is possible to compute an upper bound to the interference suffered by a task due to other interacting tasks. Thus, it is possible to provide timing guarantees for a subset of interacting hard real-time tasks. Finally, the M-BWI protocol is neutral to the underlying scheduling policy: it can be implemented in global, clustered and semi-partitioned scheduling. After introducing the M-BWI protocol, in this paper we formally prove its isolation properties, and propose an algorithm to compute an upper bound to the interference suffered by a task. Then, we describe our implementation of the protocol for the LITMUS RT real-time testbed, and measure its overhead. Finally, we compare M-BWI against FMLP and OMLP, two other protocols for resource sharing in multiprocessor systems.

  5. R. Santos, G. Lipari, E. Bini, T. Cucinotta. "On-line schedulability tests for adaptive reservations in fixed priority scheduling," Springer Real-Time Systems Journal, Vol. 48, Issue 5, pp. 601-634. September 2012. Abstract

    Adaptive reservation is a real-time scheduling technique in which each application is associated a fraction of the computational resource (a reservation) that can be dynamically adapted to the varying requirements of the application by using appropriate feedback control algorithms. An adaptive reservation is typically implemented by using an aperiodic server (e.g. sporadic server) algorithm with fixed period and variable budget. When the feedback law demands an increase of the reservation budget, the system must run a schedulability test to check if there is enough spare bandwidth to accommodate such increase. The schedulability test must be very fast, as it may be performed at each budget update, i.e. potentially at each instance of a task; yet, it must be as efficient as possible, to maximize resource usage. In this paper, we tackle the problem of performing an efficient on-line schedulability test for adaptive resource reservations in fixed priority schedulers. In the literature, a number of algorithms have been proposed for on-line admission control in fixed priority systems. We describe four of these tests, with increasing complexity and performance. In addition, we propose a novel on-line test, called Spare-Pot algorithm, which has been specifically designed for the problem at hand, and which shows a good cost/performance ratio compared to the other tests.

  6. J. Lelli, D. Faggioli, T. Cucinotta, G. Lipari. "An Experimental Comparison of Different Real-Time Schedulers on Multicore Systems," Elsevier Journal of Systems and Software (JSS), Vol. 85, Issue 10, pp. 2405-2416. October 2012. Abstract

    In this work, an experimental comparison among the Rate Monotonic (RM) and Earliest Deadline First (EDF) multi-processor real-time schedulers is performed, with a focus on soft real-time systems. We generated random workloads of synthetic periodic task sets and executed them on a big multi-core machine, using Linux as Operating System, gathering an extensive amount of data related to their exhibited performance under various real-time scheduling strategies. The comparison involves the fixed-priority scheduler for multiprocessors as available in the Linux kernel (with priorities set so as to achieve RM), and on our own implementation of EDF, both configured in global, partitioned and clustered mode. The impact of the various scheduling strategies on the performance of the applications, as well as the generated scheduling overheads, are compared presenting an extensive set of experimental results. These provide a comprehensive view of the performance achievable by the different schedulers under various workload conditions.

  7. T. Cucinotta, F. Checconi, G. Kousiouris, K. Konstanteli, S. Gogouvitis, D. Kyriazis, T. Varvarigou, A. Mazzetti, Z. Zlatev, J. Papay, M. Boniface, S. Berger, D. Lamp, T. Voith, M. Stein. "Virtualised e-Learning on the IRMOS Real-time Cloud," Springer Service Oriented Computing and Applications, Vol.6, Issue 2, pp. 151-166, June 2012.

  8. T. Cucinotta et al. "The IRMOS/ISONI Real-Time Cloud Infrastructure: a Virtualised e-Learning Case-Study," IEEE Communications Society Multimedia Communications Technical Committee (COMSOC MMTC) E-Letter, Special Issue On Multimedia Sensor Networks In Sustainable Systems, Vol. 6, No. 12, December 2011. Abstract

    Nowadays, applications are increasingly developed and made available in distributed infrastructures, where users access their services from remote. In the Cloud Computing model, applications are developed by Software-as-a- Service (SaaS) providers, by means of tools made available by Platform-as-a-Service (PaaS) providers, for being deployed over the resources made available by Infrastructure-as-a-Service (IaaS) providers. The viability of IaaS is dependent on the use of virtualisation technologies, which allow for deploying multiple virtual machines (VMs), hosting multiple Operating Systems and services, over the same physical hosts, achieving an increased server consolidation level. In this evolving scenario, more and more distributed applications with tight interactivity and timing requirements are being deployed over virtualised IaaS infrastructures. Unfortunately, when multiple VMs are deployed over the same physical resources (e.g., links and CPUs), the level of performance experienced by each VM is not stable any more, but it depends heavily on the overall workload imposed by the other VMs competing for the shared resources. However, using proper scheduling technologies and performance modelling techniques, it is possible to deploy virtualised distributed applications with a stable performance level, as being experimented with the virtualised Cloud Computing infrastructure developed in the IRMOS EU Project (http://www.irmosproject.eu/) In this paper, we show how these concepts have been practically applied to a real e-Learning application. A more extended discussion can be found in the original article appeared at the IEEE SOCA 2010 Conference.

  9. T. Cucinotta and D. Faggioli. "Handling Timing Constraints Violations in Soft Real-Time Applications as Exceptions," Elsevier Journal of Systems and Software (JSS), December 2011. Abstract

    In this paper, an exception-based programming paradigm is envisioned to deal with timing constraints violations occurring in soft real-time and multimedia applications written in the C language. In order to prove viability of the approach, a mechanism allowing to use such paradigm has been designed and implemented as an open-source library of C macros making use of the standard POSIX API (a few Linux-specific optimizations are also briefly discussed). The proposed approach has been validated by modifying mplayer, one of the most widely used multimedia player for Linux, so as to use the introduced library. An extensive experimental evaluation has been made, both when running the player alone and when mixing it with a workload of other synthetic real-time applications. In the latter case, different scheduling policies have been used, including both standard priority-based ones as available on the mainline Linux, and an experimental deadline-based one available as a separate patch. The shown results demonstrate how the exception-based paradigm is effective in improving the audio/video delay exhibited by the player achieving a superior performance and a dramatically better Quality of Experience as compared to the original heuristic frame-dropping mechanism of the player.

  10. Ruslan Asaula, T. Cucinotta, Gianluca Dini, L. Palopoli. "Trading security for control performance in distributed robotic applications," International Transactions on Systems Science and Applications (ITSSA), Vol. 7, No. 1/2, November 2011, pp. 26-39. Abstract

    Networked embedded and control systems are largely used in factory automation for production and logistics tasks. In this application domain, security has become a prominent issue due to the critical consequences a cyber attack may have in terms of safety and financial losses. Unfortunately security solutions compete against control applications for the often scarce resources of embedded platforms. In this paper, we show how security can be dealt with as one of different Quality of Service dimensions and traded for control performance in an adaptive QoS management scheme. The system is able to respond to increased resource requirements or to changes in the risk level by reconfiguring the application modes and the security modes. We offer an explanatory case study to show how this idea is implemented.

  11. T. Cucinotta, L. Abeni, L. Palopoli, G. Lipari, "A robust mechanism for adaptive scheduling of multimedia applications," ACM Transactions on Embedded Computing Systems, Vol. 10, No. 4, November 2011. Abstract

    We propose an adaptive scheduling technique to schedule highly dynamic multimedia tasks on a CPU. We use a combination of two techniques: the first one is a feedback mechanism to track the resource requirements of the tasks based on local observations. The second one is a mechanism that operates with a global visibility, reclaiming unused bandwidth. The combination proves very effective: resource reclaiming increases the robustness of the feedback, while the identification of the correct bandwidth made by the feedback increases the effectiveness of the reclamation. We offer both theoretical results and an extensive experimental validation of the approach.

  12. G. Kousiouris, T. Cucinotta, T. Varvarigou. "The Effects of Scheduling, Workload Type and Consolidation Scenarios on Virtual Machine Performance and their Prediction through Optimized Artificial Neural Networks," Elsevier Journal of Systems & Software (JSS). DOI 10.1016/j.jss.2011.04.013, 2011.

  13. Michal Sojka, Pavel Pisa, D. Faggioli, T. Cucinotta, F. Checconi, Zdenek Hanzalek, G. Lipari, "Modular Software Architecture for Flexible Reservation Mechanisms on Heterogeneous Resources," Elsevier Journal of Systems Architecture (JSA), Vol. 57, Issue 4, pp. 366-382, April 2011. Abstract

    Management, allocation and scheduling of heterogeneous resources for complex distributed real-time applications is a chal- lenging problem. Timing constraints of applications may be fulfilled by the proper use of real-time scheduling policies, admission control and enforcement of timing constraints. However, it is not easy to design basic infrastructure services that allow for easy access to the allocation of multiple heterogeneous resources in a distributed environment. In this paper, we present a middleware for providing distributed soft real-time applications with a uniform API for reserving heterogeneous resources with real-time scheduling capabilities in a distributed environment. The architecture relies on standard POSIX OS facilities, such as time management and standard TCP/IP networking services, and it is designed around CORBA, in order to facilitate modularity, flexibility and portability of the applications using it. However, real-time scheduling is supported by proper extensions at the kernel-level, plugged within the framework by means of dedicated resource managers. Our current implementation on Linux supports the reservation of the CPU, disk and network bandwidth. However, additional resource managers supporting alternative real-time schedulers for these resources, as well as additional types of resources, may be easily added. We present experimental results gathered on both synthetic applications and a real multimedia video streaming case study, showing the advantages deriving from the use of the proposed middleware. Finally, overhead figures are reported, showing the sustainability of the approach for a wide class of complex, distributed, soft real-time applications.

  14. D. Kyriazis, A. Menychtas, G. Kousiouris, K. Oberle, T. Voith, M. Boniface, E. Oliveros, T. Cucinotta, S. Berger, "A Real-time Service Oriented Infrastructure," GSTF International Journal on Computing, Vol. 1, No. 2, ISSN 2010-2283, February 2011. Abstract

    The advancements in distributed computing have driven the emergence of service-based infrastructures that allow for on-demand provision of ICT assets. Taking into consideration the complexity of distributed environments, significant challenges exist in providing and managing the offered on-demand resources with the required level of Quality of Service (QoS), especially for real-time interactive and streaming applications. In this paper we propose an approach for providing real-time QoS guarantees by enhancing service oriented infrastructures with coherent and consistent real-time attributes at various levels (application, network, storage, processing). The approach considers the full lifecycle of service-based systems including service engineering, Service Level Agreement (SLA) negotiation and management, service provisioning and monitoring. QoS parameters at application, platform and infrastructure levels are given specific attention as the basis for provisioning policies in the context of temporal constraints.

  15. K. Konstanteli, T. Cucinotta, T. Varvarigou, "Optimum Allocation of Distributed Service Workflows with Probabilistic Real-Time Guarantees," Springer Service Oriented Computing and Applications, Vol. 4, No. 4, December 2010.

  16. T. Cucinotta, L. Palopoli, L. Abeni, D. Faggioli, G. Lipari, "On the integration of application level and resource level QoS control for real-time applications," IEEE Transactions on Industrial Informatics, Vol. 6, No. 4, November 2010. Abstract

    We consider a dynamic set of soft real-time applications using a set of shared resources. Each application can execute in different modes, each one associated with a level of Quality of Service (QoS). Resources, in their turn, have different modes, each one with a speed and a power consumption, and are managed by a Reservation Based scheduler enabling a dynamic allocation of the fraction of resources (bandwidth) assigned to each application. To cope with dynamic changes of the application, we advocate an adaptive resource allocation policy organised in two nested feedback loops. The internal loop operates on the scheduling parameter to obtain a resource allocation that meets the temporal constraints of the applications. The external loop operates on the QoS level of the applications and on the power level of the resources to strike a good trade-off between the global QoS and the energy consumption. This loop comes into play whenever the workload of the application exceeds the bounds that permit the internal loop to operate correctly, or whenever it decreases below a level that permit more aggressive choices for the QoS or substantial energy saving.

  17. T. Cucinotta, L. Palopoli, "QoS Control for Pipelines of Tasks Using Multiple Resources," IEEE Transactions on Computers, Vol. 53, No. 3, pp. 416--430, March 2010, IEEE Computer Society Digital Library.

  18. T. Cucinotta, A. Mancina, G. Anastasi, G. Lipari, L. Mangeruca, R. Checcozzo, F. Rusinà, "A Real-time Service-Oriented Architecture for Industrial Automation," IEEE Transactions on Industrial Informatics, Vol. 5, n. 3, August 2009. Abstract

    Industrial automation platforms are experiencing a paradigm shift. New technologies are making their way in the area, including embedded real-time systems, standard local area networks like Ethernet, Wi-Fi and ZigBee, standard IP-based communication protocols, standard Service Oriented Architectures (SOA) and Web Services. An automation system will be composed of flexible autonomous components with Plug & Play functionality, self configuration and diagnostic, and autonomic local control that communicate through standard networking technologies. However, the introduction of these new technologies raises many important problems that need to be properly solved, one of these being the need to support real-time and Quality of Service (QoS) for hard and soft real-time applications. This paper describes a Service-Oriented Architecture enhanced with real-time capabilities for Industrial Automation. The proposed architecture allows for negotiation of the QoS requested by clients to web services, and provides temporal encapsulation of individual activities. This way, it is possible to perform an a-priori analysis of the temporal behavior of each service, and to avoid unwanted interferences among components. After describing the architecture, experimental results gathered on a real implementation of the framework (which leverages AQuoSA, a soft real-time scheduler for the Linux kernel) are presented, showing the effectiveness of the proposed solution. The experiments were performed on simple case studies designed in the context of industrial automation applications.

  19. L. Palopoli, T. Cucinotta, L. Marzario, G. Lipari, "AQuoSA - Adaptive Quality of Service Architecture," Software: Practice and Experience, April 2008, doi 10.1002/spe.883. Abstract

    This paper presents an architecture for Quality of Service (QoS) control of time- sensitive applications in multi-programmed embedded systems. In such systems, tasks must receive appropriate timeliness guarantees from the Operating System independently from one another, otherwise the QoS experienced by users may decrease. Moreover, fluctuations in time of the workloads make a static partitioning of the CPU not appropriate nor convenient, whereas an adaptive allocation based on an on-line monitoring of the application behaviour leads to an optimum design. By combining a resource reservation scheduler and a feedback based mechanism, we allow applications to meet their QoS requirements with the minimum possible impact on CPU occupation. We implemented the framework in AQuoSA [8], a software architecture that runs on top of the Linux kernel.We provide extensive experimental validation of our results and offer evaluation of the introduced overhead, which is perfectly sustainable in the class of addressed applications.

  20. L. Abeni, T. Cucinotta, G. Lipari, L. Marzario, L. Palopoli, "QoS Management through adaptive reservations," Real-Time Systems Journal, Vol. 29, Issue 2-3, March 2005, ISSN:0922-6443, Kluwer Academic. Abstract

    Reservation based (RB) scheduling is a class of scheduling algorithms that is well-suited for a large class of soft real-time applications. They are based on a "bandwidth" abstraction, meaning that a task is given the illusion of executing on a dedicated slower processor. In this context, a crucial design issue is deciding the bandwidth that each task should receive. The point we advocate is that, in presence of large fluctuations on the computation requirements of the tasks, it can be a beneficial choice to dynamically adapt the bandwidth based on QoS measurements and on the subsequent application of feedback control (adaptive reservations). In this paper, we present two novel contributions to this research area. First, we propose three new control algorithms inspired to the ideas of stochastic control. Second, we present a flexible and modular software architecture for adaptive reservations. An important feature of this architecture is that it is realised by means of a minimally invasive set of modifications to the Linux kernel.

  21. T. Cucinotta, M. Di Natale, D. Corcoran, "An open middleware for smart-cards," Computer Science Software Engineering (CSSE) Journal, Vol. 20, No. 6, November 2005. Abstract

    This paper presents an open and modular middleware for smart cards, providing a simple abstraction of the device to application developers. The software is interoperable across multiple card devices, and portable across various open platforms. The architectural design is centred around the definition of a new API that allows protected access to the storage and cryptographic facilities of a smart card. In the envisioned architecture, a smart card driver architecture is partitioned into a lower card-dependent component, that formats and exchanges APDUs with the external device, and a higher cardindependent component, that implements more sophisticated services and interfaces, such as the well known PKCS-11 standard. Each layer can focus on a smaller set of functionality, thus reducing the effort required for the development as well as the testing and maintenance of each component. The proposed architecture, along with a set of pilot applications such as secure remote shell, secure web services, local login and digital signature, has been developed and tested on various platforms, including Open BSD, Linux, Solaris and Mac OS X, proving effectiveness of the new approach.

  22. T. Cucinotta, R. Brigo, M. Di Natale, "A fingerprint matching algorithm for programmable smart cards," Information Security Bulletin Journal, Vol. 10, November 2005. Abstract

    This paper presents a hybrid fingerprint matching algorithm for user authentication based on the fusion of heterogeneous schemes, and designed to run on programmable smart cards. The approach is based on the well-known texture vector and minutiae based techniques, where image processing and feature extraction occur on the host, while the card device performs the final match against the on-board template, which is never revealed to the outside world. This increases security of the template itself and of the applications using it. The matching algorithms have been tuned in order to achieve an acceptable performance despite computation and memory constraints. Experimental results, gathered from our implementation on a Java Card device, highlight feasibility of the hybrid approach, and show to what extent it is possible to trade precision for speed in the verification process, with an appropriate tuning of the on-board matching parameters.

Book Chapters

  1. T. Cucinotta, G. Lipari, Lutz Schubert. "Operating System and Scheduling for Future Multi-core and Many-Core Platforms," Chapter accepted to appear in the book "Programming Multi-core and Many-Core Computing Systems", Wiley Interscience.

  2. Lutz Schubert, Stephan Wesner, Daniel R. Bonilla, T. Cucinotta. "Autonomic Distribution and Adaptation," Chapter accepted to appear in the book "Programming Multi-core and Many-Core Computing Systems", Wiley Interscience.

  3. T. Cucinotta and S. V. Gogouvitis. "Real-Time Attributes in Operating Systems," Achieving Real-Time in Distributed Computing: From Grids to Clouds. IGI Global, July 2011. DOI: 10.4018/978-1-60960-827-9

  4. Gregory Katsaros and T. Cucinotta. "Programming Interfaces for Realtime and Cloud-based Computing," Achieving Real-Time in Distributed Computing: From Grids to Clouds. IGI Global, July 2011. DOI: 10.4018/978-1-60960-827-9

  5. S. V. Gogouvitis, K. G. Konstanteli, D. Kyriazis, G. Katsaros, T. Cucinotta, M. Boniface. "Workflow Management Systems in Distributed Environments," Achieving Real-Time in Distributed Computing: From Grids to Clouds. IGI Global, July 2011. DOI: 10.4018/978-1-60960-827-9

  6. E. Oliveros, T. Cucinotta, S. C. Phillips, Xiaoyu Yang, T. Voith, Stuart Middleton. "Monitoring and Metering in the Cloud," Achieving Real-Time in Distributed Computing: From Grids to Clouds. IGI Global, July 2011. DOI: 10.4018/978-1-60960-827-9

  7. S. Narasimhamurthy, M. Muggeridge, S. Waldschmidt, F. Checconi, T. Cucinotta. "Data Storage in Cloud Based Real-Time Environments," Achieving Real-Time in Distributed Computing: From Grids to Clouds. IGI Global, July 2011. DOI: 10.4018/978-1-60960-827-9

  8. S. Berger, D. Lamp, M. Stein, T. Voith, T. Cucinotta, M. Bertogna. "Execution & Resource Management in QoS-aware Virtualized Infrastructures," Achieving Real-Time in Distributed Computing: From Grids to Clouds. IGI Global, July 2011. DOI: 10.4018/978-1-60960-827-9

Publications on national magazines

  1. T. Cucinotta, "Firma digitale e lavoro cooperativo: aspetti tecnologici", pubblicato su "I nuovi scenari del marketing assicurativo", Franco Angeli Editore, 2004

  2. T. Cucinotta, "Firma digitale e assicurazioni: aspetti tecnologici," pubblicato su "L'economia digitale e il settore assicurativo", DEA Quaderni di Impresa Assicurativa, Giuffrè Editore, 2003

  3. M. Di Natale, T. Cucinotta, P. Ancilotti, "Lo sviluppo di una architettura modulare open-source per i servizi della PA: considerazioni tecniche e organizzative," atti del forum "SALPA: Sapere Aperto e Libero nella Pubblica Amministrazione", Marzo 2004, Pisa


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