Orazio Tomarchio | Università di Catania (original) (raw)

Papers by Orazio Tomarchio

Research paper thumbnail of Integration of mobile agents and genetic algorithms for efficient dynamic network resource allocation

An agent based approach is investigated to build a framework where resource allocation is provide... more An agent based approach is investigated to build a framework where resource allocation is provided under the control of different and often competing stake-holders (users, network providers, service providers, etc.). This paper also describes the efficient integration and adoption of mobile agents and genetic algorithms in the implementation of an effective strategy for the development of effective market based routes

Research paper thumbnail of Management of QoS with software agents

As distributed multimedia applications become more widely diffused, systems for QoS management ar... more As distributed multimedia applications become more widely diffused, systems for QoS management are increasingly essential. In this paper we present an architecture for distributed QoS management based on software agents. We discuss the advantages of using agent technology in a problem inherently distributed and complex such as QoS management. Besides introducing several negotiation and coordination techniques among agents as fundamental properties for QoS management, it is argued in favor of decision making based on analytical and simulative modeling techniques. Furthermore, design and implementation issues are discussed in detail and our Java-based platform for an agent-based QoS management is introduced.

Research paper thumbnail of An agent-based framework for QoS management

As distributed multimedia applications become more widely di used, systems for QoS management are... more As distributed multimedia applications become more widely di used, systems for QoS management are increasingly essential. In this paper we will present an architecture for distributed QoS management based on software agents. A software agent is a software module often equipped with arti cial intelligence mechanism which is capable, autonomously or in cooperation with other agents, of solving a certain problem or carrying out a certain task. We will show the advantage of an agent-based infrastructure in a problem inherently distributed and complex such as QoS management.

Research paper thumbnail of QoS-adaptation by software agents in the presence of defective reservation mechanisms in the Internet

Proceedings Third IEEE Symposium on Computers and Communications. ISCC'98. (Cat. No.98EX166), 1998

Originally, the Internet delivered b est-e ort service quality with respect to end-to-end delay. ... more Originally, the Internet delivered b est-e ort service quality with respect to end-to-end delay. Recently, extensions such as RSVP have been proposed to provide guaranteed real-time services as well. Unfortunately, network resources, such as routers, do not yet fully support RSVP reservation protocols so that guarantees cannot truly be given. In this paper, we suggest to follow the paradigm of open programmable networks for a more complete QoS provisioning. Reservation gaps or tunnels are dynamically closed by means of a software-agent approach that is exibly deployed for an application oriented QoS support. Agents are dynamically located to such tunnels in order to monitor the tunnels, to provide feed-back information in case of QoS violations, and to decide on possible compensating measures to be taken.

Research paper thumbnail of Tunnel Agents for Enhanced QoS in the Internet

Originally, the Internet delivered best-e ort service quality with respect to end-to-end delay. R... more Originally, the Internet delivered best-e ort service quality with respect to end-to-end delay. Recently, extensions such as RSVP have been proposed to provide guaranteed real-time services as well. Unfortunately, network resources, such as routers, do not yet fully support RSVP reservation protocols so that guarantees cannot truly be given. In this paper, we suggest to follow the paradigm of open programmable networks for a more complete QoS provisioning. Reservation gaps or tunnels are dynamically closed by means of a software-agent approach that is exibly deployed for an application oriented QoS support. Agents are dynamically located to such tunnels in order to monitor the tunnels, to provide feed-back information in case of QoS violations, and to decide on possible compensating measures to be taken. One such possible measure is redistribution of user speci ed QoS budgets, like end-to-end delay, among the involved RSVP-capable network components. Re-routing support is another feature achievable by exploiting mobility capabilities of the agent approach based on our Java platform.

Research paper thumbnail of An SLA-based Broker for Cloud Infrastructures

Journal of Grid Computing, 2013

The breakthrough of Cloud comes from its service oriented perspective where everything, including... more The breakthrough of Cloud comes from its service oriented perspective where everything, including the infrastructure, is provided "as a service". This model is really attractive and convenient for both providers and consumers, as a consequence the Cloud paradigm is quickly growing and widely spreading, also in non commercial contexts. In such a scenario, we propose to incorporate some elements of volunteer computing into the Cloud paradigm through the Cloud@Home solution, involving into the mix nodes and devices provided by potentially any owners or administrators, disclosing high computational resources to contributors and also allowing to maximize their utilization.

Research paper thumbnail of Design and development of a practical security model for a mobile agent system

Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications, 2002

Since its appearance, mobile agent technology has been considered as a new and flexible paradigm ... more Since its appearance, mobile agent technology has been considered as a new and flexible paradigm for distributed application development. However, because of code mobility, this paradigm produces new threats to security too, which are of central importance when proposing this technology for commercial applications. In the paper we show the security services which have been specifically designed and developed for the MAP agent system. Early performance measurement show how the overhead needed by the security mechanisms introduced can be acceptable if compared with the functionalities provided.

Research paper thumbnail of Extending the MASIF Location Service in the MAP agent system

The recent development in the field of telecommunication networks has enabled the evolution of di... more The recent development in the field of telecommunication networks has enabled the evolution of distributed systems, and has favoured the development of a new generation of applications based on the use of mobile agents. In fact, during the last few years, several agent platforms have been created; however, the architectures and implementation of such platforms are very different, and this makes their interaction difficult. In order to favour the interaction among differently implemented platforms, the OMG has recently proposed the MASIF standard, which includes some definitions and interfaces which all platforms have to comply with. In this paper we present the MAP platform for developing and managing mobile agents; it complies with MASIF, in order to communicate and interact with similar platforms provided that they comply with the mentioned standard. Besides, we present a mechanism, which has been implemented in the MAP, which extends MASIF's functionalities so to enable the interaction among agents and agent systems operating in different regions.

Research paper thumbnail of Mobile Agents and Legacy Systems: How to Integrate Alternative Communication Paradigms

Lecture Notes in Computer Science, 2001

ABSTRACT

Research paper thumbnail of MAP: Design and implementation of a mobile agents' platform

Journal of Systems Architecture, 2000

The recent development of telecommunication networks has contributed to the success of applicatio... more The recent development of telecommunication networks has contributed to the success of applications such as information retrieval and electronic commerce, as well as all the services that take advantage of communication in distributed systems. In this area, the emerging technology of mobile agents aroused considerable interest. Mobile agents are applications that can move through the network for carrying out a given task on behalf of the user. In this work we present a platform (called MAP (Mobile Agents Platform)) for the development and the management of mobile agents. The language used both for developing the platform and for carrying out the agents is Java. The platform gives the user all the basic tools needed for creating some applications based on the use of agents. It enables us to create, run, suspend, resume, deactivate, reactivate local agents, to stop their execution, to make them communicate each other and migrate.

Research paper thumbnail of Active Monitoring in Grid Environments Using Mobile Agent Technology

The Kluwer International Series in Engineering and Computer Science, 2000

Monitoring distributed computational resources effectively is a crucial factor for high-performan... more Monitoring distributed computational resources effectively is a crucial factor for high-performance distributed computation. Performance analysis and tuning, scheduling strategies, fault detection, are only some of the activities that require monitoring facilities. In this paper we present a mobile agent-based monitoring architecture. After explaining the reasons why this technology is adequate to cope with Grid systems' heterogeneity, a description of the basic components of the system designed is provided. We also present some considerations on the high degree of flexibility that can be reached with the proposed approach.

Research paper thumbnail of Security mechanisms for the MAP agent system

Proceedings 8th Euromicro Workshop on Parallel and Distributed Processing, 1999

which has recently obtained a great attention from researcher and practitioners. Interesting appl... more which has recently obtained a great attention from researcher and practitioners. Interesting applications exist in the fields of distributed systems management, mobility and information retrieval. But, although widely recognized as a crucial point to be addressed, security has not been pursued in a satisfactory way yet. Most of all the existing software environment for agent programming do not offer security features or provide only partial implementations. In this paper we propose a security schema for mobile agent and describe its implementation inside the MAP platform. Some experimental results are also provide to evaluate the overhead introduced from the adoption of the proposed security mechanism.

Research paper thumbnail of On the use of Java to make Software Tools Accessible on the Web

Although the Web makes a large amount of information easy to access for a great number of users, ... more Although the Web makes a large amount of information easy to access for a great number of users, it does not o er simple mechanisms to facilitate the use of a computation-oriented application on the Internet. The Java language developed by Sun Microsystems makes the development of such applications easier. In this paper we show how this technology can be used for creating a network computing platform for the Web sharing of applications which were not speci cally devised for network use. The platform developed is also equipped with adequate security mechanisms which provide authentication services and, if required, encryption. The approach proposed has been applied to porting the Sharpe software package for performance, dependability and performability analysis of computer and communication systems onto the Web. A similar approach has been adopted in developing the tool WebSPN for the analysis of non-Markovian Stochastic Petri Nets.

Research paper thumbnail of Increasing application accessibility through Java

IEEE Internet Computing, 2000

Java can be used to create a network computing platform that lets users share applications not sp... more Java can be used to create a network computing platform that lets users share applications not specifically devised for the Web. The authors used one such platform to port an existing tool and develop a new application.

Research paper thumbnail of Design of a media service provider architecture for the Internet

Proceedings ISCC 2000. Fifth IEEE Symposium on Computers and Communications, 2000

... [6] Cyril U. Orji, Patrick 0. Bobbie, Kingsley C. Nwosu - “Spatio temporal effects of multime... more ... [6] Cyril U. Orji, Patrick 0. Bobbie, Kingsley C. Nwosu - “Spatio temporal effects of multimedia objects storage and delivery for video-on-demand systems” - Multi-media Systems (1997) 5 :39-52 [8] A. Calvagna, A. Puliafito, L. Vita - “DAVID: De-sign and Implementation of a ...

Research paper thumbnail of Programmable agents for flexible QoS management in IP networks

IEEE Journal on Selected Areas in Communications, 2000

Network programmabillity seems to be a promising solution to network management and QoS control. ... more Network programmabillity seems to be a promising solution to network management and QoS control. Software mobile-agents technology is boosting the evolution toward application level control of network functionalities. Code may be deployed in the network dynamically and on-demand for the bene t of applications or application classes. Agents support a dynamic distribution of control and management functions across networks, thus increasing exibility and e ciency. We propose to use mobile-agent technology to overcome some of the problems inherent in current Internet technology. We focus our attention to QoS monitoring, being locally signicant in network sub-domains, and realize a QoS management strategy in response to variations of user, customer of application requirements and of the network state. We describe our experience and the results obtained from our test-bed, where software agents are instantiated, executed, migrated and suspended in order to implement exible QoS management in IP networks.

Research paper thumbnail of W-MAP: A Web-accessible Mobile Agents Platform

Distributed and Parallel Systems, 2000

We present W-MAP, a Web-accessible platform for thedevelopment and the management of mobile agent... more We present W-MAP, a Web-accessible platform for thedevelopment and the management of mobile agents. Thelanguage used both for developing the platform and for carryingout the agents is Java. The platform gives the user allthe basic tools needed for creating some applications basedon the use of agents. It allows to create, run, suspend, resume,deactivate, reactivate agents, to stop their execution,to make

Research paper thumbnail of Design and implementation of a web-based non-markovian stochastic petri net tool

Abstract. This paper describes a new modeling tool for the analysis of non-Markovian stochastic P... more Abstract. This paper describes a new modeling tool for the analysis of non-Markovian stochastic Petri nets (SPN). This tool, called Web-SPN, provides a discrete time approximation of the stochastic behavior of the marking process which results in the ...

Research paper thumbnail of A Java-based distributed network management architecture

Research paper thumbnail of An SLA-based Broker for Cloud Infrastructures

Journal of Grid Computing, 2013

The breakthrough of Cloud comes from its service oriented perspective where everything, including... more The breakthrough of Cloud comes from its service oriented perspective where everything, including the infrastructure, is provided "as a service". This model is really attractive and convenient for both providers and consumers, as a consequence the Cloud paradigm is quickly growing and widely spreading, also in non commercial contexts. In such a scenario, we propose to incorporate some elements of volunteer computing into the Cloud paradigm through the Cloud@Home solution, involving into the mix nodes and devices provided by potentially any owners or administrators, disclosing high computational resources to contributors and also allowing to maximize their utilization.

Research paper thumbnail of Integration of mobile agents and genetic algorithms for efficient dynamic network resource allocation

An agent based approach is investigated to build a framework where resource allocation is provide... more An agent based approach is investigated to build a framework where resource allocation is provided under the control of different and often competing stake-holders (users, network providers, service providers, etc.). This paper also describes the efficient integration and adoption of mobile agents and genetic algorithms in the implementation of an effective strategy for the development of effective market based routes

Research paper thumbnail of Management of QoS with software agents

As distributed multimedia applications become more widely diffused, systems for QoS management ar... more As distributed multimedia applications become more widely diffused, systems for QoS management are increasingly essential. In this paper we present an architecture for distributed QoS management based on software agents. We discuss the advantages of using agent technology in a problem inherently distributed and complex such as QoS management. Besides introducing several negotiation and coordination techniques among agents as fundamental properties for QoS management, it is argued in favor of decision making based on analytical and simulative modeling techniques. Furthermore, design and implementation issues are discussed in detail and our Java-based platform for an agent-based QoS management is introduced.

Research paper thumbnail of An agent-based framework for QoS management

As distributed multimedia applications become more widely di used, systems for QoS management are... more As distributed multimedia applications become more widely di used, systems for QoS management are increasingly essential. In this paper we will present an architecture for distributed QoS management based on software agents. A software agent is a software module often equipped with arti cial intelligence mechanism which is capable, autonomously or in cooperation with other agents, of solving a certain problem or carrying out a certain task. We will show the advantage of an agent-based infrastructure in a problem inherently distributed and complex such as QoS management.

Research paper thumbnail of QoS-adaptation by software agents in the presence of defective reservation mechanisms in the Internet

Proceedings Third IEEE Symposium on Computers and Communications. ISCC'98. (Cat. No.98EX166), 1998

Originally, the Internet delivered b est-e ort service quality with respect to end-to-end delay. ... more Originally, the Internet delivered b est-e ort service quality with respect to end-to-end delay. Recently, extensions such as RSVP have been proposed to provide guaranteed real-time services as well. Unfortunately, network resources, such as routers, do not yet fully support RSVP reservation protocols so that guarantees cannot truly be given. In this paper, we suggest to follow the paradigm of open programmable networks for a more complete QoS provisioning. Reservation gaps or tunnels are dynamically closed by means of a software-agent approach that is exibly deployed for an application oriented QoS support. Agents are dynamically located to such tunnels in order to monitor the tunnels, to provide feed-back information in case of QoS violations, and to decide on possible compensating measures to be taken.

Research paper thumbnail of Tunnel Agents for Enhanced QoS in the Internet

Originally, the Internet delivered best-e ort service quality with respect to end-to-end delay. R... more Originally, the Internet delivered best-e ort service quality with respect to end-to-end delay. Recently, extensions such as RSVP have been proposed to provide guaranteed real-time services as well. Unfortunately, network resources, such as routers, do not yet fully support RSVP reservation protocols so that guarantees cannot truly be given. In this paper, we suggest to follow the paradigm of open programmable networks for a more complete QoS provisioning. Reservation gaps or tunnels are dynamically closed by means of a software-agent approach that is exibly deployed for an application oriented QoS support. Agents are dynamically located to such tunnels in order to monitor the tunnels, to provide feed-back information in case of QoS violations, and to decide on possible compensating measures to be taken. One such possible measure is redistribution of user speci ed QoS budgets, like end-to-end delay, among the involved RSVP-capable network components. Re-routing support is another feature achievable by exploiting mobility capabilities of the agent approach based on our Java platform.

Research paper thumbnail of An SLA-based Broker for Cloud Infrastructures

Journal of Grid Computing, 2013

The breakthrough of Cloud comes from its service oriented perspective where everything, including... more The breakthrough of Cloud comes from its service oriented perspective where everything, including the infrastructure, is provided "as a service". This model is really attractive and convenient for both providers and consumers, as a consequence the Cloud paradigm is quickly growing and widely spreading, also in non commercial contexts. In such a scenario, we propose to incorporate some elements of volunteer computing into the Cloud paradigm through the Cloud@Home solution, involving into the mix nodes and devices provided by potentially any owners or administrators, disclosing high computational resources to contributors and also allowing to maximize their utilization.

Research paper thumbnail of Design and development of a practical security model for a mobile agent system

Proceedings ISCC 2002 Seventh International Symposium on Computers and Communications, 2002

Since its appearance, mobile agent technology has been considered as a new and flexible paradigm ... more Since its appearance, mobile agent technology has been considered as a new and flexible paradigm for distributed application development. However, because of code mobility, this paradigm produces new threats to security too, which are of central importance when proposing this technology for commercial applications. In the paper we show the security services which have been specifically designed and developed for the MAP agent system. Early performance measurement show how the overhead needed by the security mechanisms introduced can be acceptable if compared with the functionalities provided.

Research paper thumbnail of Extending the MASIF Location Service in the MAP agent system

The recent development in the field of telecommunication networks has enabled the evolution of di... more The recent development in the field of telecommunication networks has enabled the evolution of distributed systems, and has favoured the development of a new generation of applications based on the use of mobile agents. In fact, during the last few years, several agent platforms have been created; however, the architectures and implementation of such platforms are very different, and this makes their interaction difficult. In order to favour the interaction among differently implemented platforms, the OMG has recently proposed the MASIF standard, which includes some definitions and interfaces which all platforms have to comply with. In this paper we present the MAP platform for developing and managing mobile agents; it complies with MASIF, in order to communicate and interact with similar platforms provided that they comply with the mentioned standard. Besides, we present a mechanism, which has been implemented in the MAP, which extends MASIF's functionalities so to enable the interaction among agents and agent systems operating in different regions.

Research paper thumbnail of Mobile Agents and Legacy Systems: How to Integrate Alternative Communication Paradigms

Lecture Notes in Computer Science, 2001

ABSTRACT

Research paper thumbnail of MAP: Design and implementation of a mobile agents' platform

Journal of Systems Architecture, 2000

The recent development of telecommunication networks has contributed to the success of applicatio... more The recent development of telecommunication networks has contributed to the success of applications such as information retrieval and electronic commerce, as well as all the services that take advantage of communication in distributed systems. In this area, the emerging technology of mobile agents aroused considerable interest. Mobile agents are applications that can move through the network for carrying out a given task on behalf of the user. In this work we present a platform (called MAP (Mobile Agents Platform)) for the development and the management of mobile agents. The language used both for developing the platform and for carrying out the agents is Java. The platform gives the user all the basic tools needed for creating some applications based on the use of agents. It enables us to create, run, suspend, resume, deactivate, reactivate local agents, to stop their execution, to make them communicate each other and migrate.

Research paper thumbnail of Active Monitoring in Grid Environments Using Mobile Agent Technology

The Kluwer International Series in Engineering and Computer Science, 2000

Monitoring distributed computational resources effectively is a crucial factor for high-performan... more Monitoring distributed computational resources effectively is a crucial factor for high-performance distributed computation. Performance analysis and tuning, scheduling strategies, fault detection, are only some of the activities that require monitoring facilities. In this paper we present a mobile agent-based monitoring architecture. After explaining the reasons why this technology is adequate to cope with Grid systems' heterogeneity, a description of the basic components of the system designed is provided. We also present some considerations on the high degree of flexibility that can be reached with the proposed approach.

Research paper thumbnail of Security mechanisms for the MAP agent system

Proceedings 8th Euromicro Workshop on Parallel and Distributed Processing, 1999

which has recently obtained a great attention from researcher and practitioners. Interesting appl... more which has recently obtained a great attention from researcher and practitioners. Interesting applications exist in the fields of distributed systems management, mobility and information retrieval. But, although widely recognized as a crucial point to be addressed, security has not been pursued in a satisfactory way yet. Most of all the existing software environment for agent programming do not offer security features or provide only partial implementations. In this paper we propose a security schema for mobile agent and describe its implementation inside the MAP platform. Some experimental results are also provide to evaluate the overhead introduced from the adoption of the proposed security mechanism.

Research paper thumbnail of On the use of Java to make Software Tools Accessible on the Web

Although the Web makes a large amount of information easy to access for a great number of users, ... more Although the Web makes a large amount of information easy to access for a great number of users, it does not o er simple mechanisms to facilitate the use of a computation-oriented application on the Internet. The Java language developed by Sun Microsystems makes the development of such applications easier. In this paper we show how this technology can be used for creating a network computing platform for the Web sharing of applications which were not speci cally devised for network use. The platform developed is also equipped with adequate security mechanisms which provide authentication services and, if required, encryption. The approach proposed has been applied to porting the Sharpe software package for performance, dependability and performability analysis of computer and communication systems onto the Web. A similar approach has been adopted in developing the tool WebSPN for the analysis of non-Markovian Stochastic Petri Nets.

Research paper thumbnail of Increasing application accessibility through Java

IEEE Internet Computing, 2000

Java can be used to create a network computing platform that lets users share applications not sp... more Java can be used to create a network computing platform that lets users share applications not specifically devised for the Web. The authors used one such platform to port an existing tool and develop a new application.

Research paper thumbnail of Design of a media service provider architecture for the Internet

Proceedings ISCC 2000. Fifth IEEE Symposium on Computers and Communications, 2000

... [6] Cyril U. Orji, Patrick 0. Bobbie, Kingsley C. Nwosu - “Spatio temporal effects of multime... more ... [6] Cyril U. Orji, Patrick 0. Bobbie, Kingsley C. Nwosu - “Spatio temporal effects of multimedia objects storage and delivery for video-on-demand systems” - Multi-media Systems (1997) 5 :39-52 [8] A. Calvagna, A. Puliafito, L. Vita - “DAVID: De-sign and Implementation of a ...

Research paper thumbnail of Programmable agents for flexible QoS management in IP networks

IEEE Journal on Selected Areas in Communications, 2000

Network programmabillity seems to be a promising solution to network management and QoS control. ... more Network programmabillity seems to be a promising solution to network management and QoS control. Software mobile-agents technology is boosting the evolution toward application level control of network functionalities. Code may be deployed in the network dynamically and on-demand for the bene t of applications or application classes. Agents support a dynamic distribution of control and management functions across networks, thus increasing exibility and e ciency. We propose to use mobile-agent technology to overcome some of the problems inherent in current Internet technology. We focus our attention to QoS monitoring, being locally signicant in network sub-domains, and realize a QoS management strategy in response to variations of user, customer of application requirements and of the network state. We describe our experience and the results obtained from our test-bed, where software agents are instantiated, executed, migrated and suspended in order to implement exible QoS management in IP networks.

Research paper thumbnail of W-MAP: A Web-accessible Mobile Agents Platform

Distributed and Parallel Systems, 2000

We present W-MAP, a Web-accessible platform for thedevelopment and the management of mobile agent... more We present W-MAP, a Web-accessible platform for thedevelopment and the management of mobile agents. Thelanguage used both for developing the platform and for carryingout the agents is Java. The platform gives the user allthe basic tools needed for creating some applications basedon the use of agents. It allows to create, run, suspend, resume,deactivate, reactivate agents, to stop their execution,to make

Research paper thumbnail of Design and implementation of a web-based non-markovian stochastic petri net tool

Abstract. This paper describes a new modeling tool for the analysis of non-Markovian stochastic P... more Abstract. This paper describes a new modeling tool for the analysis of non-Markovian stochastic Petri nets (SPN). This tool, called Web-SPN, provides a discrete time approximation of the stochastic behavior of the marking process which results in the ...

Research paper thumbnail of A Java-based distributed network management architecture

Research paper thumbnail of An SLA-based Broker for Cloud Infrastructures

Journal of Grid Computing, 2013

The breakthrough of Cloud comes from its service oriented perspective where everything, including... more The breakthrough of Cloud comes from its service oriented perspective where everything, including the infrastructure, is provided "as a service". This model is really attractive and convenient for both providers and consumers, as a consequence the Cloud paradigm is quickly growing and widely spreading, also in non commercial contexts. In such a scenario, we propose to incorporate some elements of volunteer computing into the Cloud paradigm through the Cloud@Home solution, involving into the mix nodes and devices provided by potentially any owners or administrators, disclosing high computational resources to contributors and also allowing to maximize their utilization.