R. Giunta, F. Messina, G. Pappalardo, L. Toscano, E. Tramontana
In a typical grid environment, replicas are spread over storage hosts, so as to increase availability and reduce files transfer times. Generally, the grid middleware lets users choose the storage host that will be serving the replica. However, having users able to choose could adversely affect network conditions and increase transfer times. This paper proposes two replica selection policies that choose one among the storage hosts holding a requested replica. The selection policies try to minimise file transfer time by extracting the least loaded host or the closest among unloaded hosts. It is shown that overall performances for transferring replicas depend on network topology, latency and bandwidth of links, and load of storage hosts and links.
{"title":"Testing Replica Selection Policies in a Pan-European Grid VO","authors":"R. Giunta, F. Messina, G. Pappalardo, L. Toscano, E. Tramontana","doi":"10.1109/WETICE.2008.48","DOIUrl":"https://doi.org/10.1109/WETICE.2008.48","url":null,"abstract":"In a typical grid environment, replicas are spread over storage hosts, so as to increase availability and reduce files transfer times. Generally, the grid middleware lets users choose the storage host that will be serving the replica. However, having users able to choose could adversely affect network conditions and increase transfer times. This paper proposes two replica selection policies that choose one among the storage hosts holding a requested replica. The selection policies try to minimise file transfer time by extracting the least loaded host or the closest among unloaded hosts. It is shown that overall performances for transferring replicas depend on network topology, latency and bandwidth of links, and load of storage hosts and links.","PeriodicalId":259447,"journal":{"name":"2008 IEEE 17th Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116438155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rocco Aversa, B. D. Martino, Renato Donini, S. Venticinque
Advanced grid functionalities and applications can be developed exploiting mobile agents technology. State-full migration can help to distribute computation where data reside and among new available and less busy machines. However when mobile agent technology is used new kinds of interaction facilities, such as cloning and migration, require execution of agent platforms, which represent an additional software layer that affects system performances. Also underlying hardware architecture can affect agent platform behaviour in an unexpected way. It means that is necessary to predict dynamics of workload distribution and to monitor system utilization in order to design effective load balancing strategies. We propose here a software architecture that, using results of system monitoring, applies a load balancing strategy to maintain in a fixed range threshold performances of a mobile agents based application.
{"title":"Load Balancing of Mobile Agents Based Applications in Grid Systems","authors":"Rocco Aversa, B. D. Martino, Renato Donini, S. Venticinque","doi":"10.1109/WETICE.2008.47","DOIUrl":"https://doi.org/10.1109/WETICE.2008.47","url":null,"abstract":"Advanced grid functionalities and applications can be developed exploiting mobile agents technology. State-full migration can help to distribute computation where data reside and among new available and less busy machines. However when mobile agent technology is used new kinds of interaction facilities, such as cloning and migration, require execution of agent platforms, which represent an additional software layer that affects system performances. Also underlying hardware architecture can affect agent platform behaviour in an unexpected way. It means that is necessary to predict dynamics of workload distribution and to monitor system utilization in order to design effective load balancing strategies. We propose here a software architecture that, using results of system monitoring, applies a load balancing strategy to maintain in a fixed range threshold performances of a mobile agents based application.","PeriodicalId":259447,"journal":{"name":"2008 IEEE 17th Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120957949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Paolo G. Giarrusso, G. Pappalardo, L. Toscano, E. Tramontana
Developing distributed applications for the Grid is a difficult task, since several concerns intertwine within them and hence must be coped with simultaneously. Moreover, when deploying application classes, several needs should be considered, such as their characteristics, user preferences, and runtime conditions of available hosts. RexMidas is a framework that automatically transforms a centralised Java application into a distributed, possibly Grid-enabled, version. RexMidas' support for remote allocation of, and communication among, class instances, is transparent, in that original application classes need not be modified (or available) at the source level. For remote allocation RexMidas adopts policies that try to strike a balance between choosing capable hosts, equipped with the necessary libraries, and minimising the overhead of communication between remote objects.
{"title":"RexMidas: A Reflective Middleware for Transparently and Effectively Distributing Objects on a Grid System","authors":"Paolo G. Giarrusso, G. Pappalardo, L. Toscano, E. Tramontana","doi":"10.1109/WETICE.2008.49","DOIUrl":"https://doi.org/10.1109/WETICE.2008.49","url":null,"abstract":"Developing distributed applications for the Grid is a difficult task, since several concerns intertwine within them and hence must be coped with simultaneously. Moreover, when deploying application classes, several needs should be considered, such as their characteristics, user preferences, and runtime conditions of available hosts. RexMidas is a framework that automatically transforms a centralised Java application into a distributed, possibly Grid-enabled, version. RexMidas' support for remote allocation of, and communication among, class instances, is transparent, in that original application classes need not be modified (or available) at the source level. For remote allocation RexMidas adopts policies that try to strike a balance between choosing capable hosts, equipped with the necessary libraries, and minimising the overhead of communication between remote objects.","PeriodicalId":259447,"journal":{"name":"2008 IEEE 17th Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130039988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soufiane Rouibia, Jonathan Vayn, Olivier Beauvais, G. Urvoy-Keller
BitTorrent is a popular p2p file replication application, which aims at replicating a given content as fast as possible on a set of peers. The algorithms of BitTorrent used to elect remote peers with whom a peer collaborates and also which pieces of the content it offers, have proved to be highly efficient. This means that a high level of parallelism is achieved among the peers as a given peer always has a high chance to find another peer that holds content it is currently missing. Still, at the beginning of a BitTorrent session, pieces of the content have to be obtained from only a few peers (in general a single one called the initial seed) that hold a full copy of the file to be replicated. In this work, we aim at evaluating the ability of a BitTorrent session to survive to a denial of service attack that would disconnect the initial seed from the network. We address this issue through experimentation. Our main conclusion is that BitTorrent is highly resilient to this attack as neither the ability to obtain a full copy of the content nor the actual replication speed are affected by the disconnection of the initial seed if the attack is not carried out at the very early stage of the session.
{"title":"Early Stage Denial of Service Attacks in BitTorrent: An Experimental Study","authors":"Soufiane Rouibia, Jonathan Vayn, Olivier Beauvais, G. Urvoy-Keller","doi":"10.1109/WETICE.2008.35","DOIUrl":"https://doi.org/10.1109/WETICE.2008.35","url":null,"abstract":"BitTorrent is a popular p2p file replication application, which aims at replicating a given content as fast as possible on a set of peers. The algorithms of BitTorrent used to elect remote peers with whom a peer collaborates and also which pieces of the content it offers, have proved to be highly efficient. This means that a high level of parallelism is achieved among the peers as a given peer always has a high chance to find another peer that holds content it is currently missing. Still, at the beginning of a BitTorrent session, pieces of the content have to be obtained from only a few peers (in general a single one called the initial seed) that hold a full copy of the file to be replicated. In this work, we aim at evaluating the ability of a BitTorrent session to survive to a denial of service attack that would disconnect the initial seed from the network. We address this issue through experimentation. Our main conclusion is that BitTorrent is highly resilient to this attack as neither the ability to obtain a full copy of the content nor the actual replication speed are affected by the disconnection of the initial seed if the attack is not carried out at the very early stage of the session.","PeriodicalId":259447,"journal":{"name":"2008 IEEE 17th Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130944208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coordinating tasks is one of the main activities of every grid middleware. There are several ways to achieve this goal, for example using publish/subscribe systems or workflow engines. In this article we will analyse another possible model: tuple spaces. The tuple space model has been successfully used for years for coordinating tasks in computational applications and has interesting characteristics like the support to open systems, allowing an application to scale without the need to reimplement it. This article will describe our experience in developing a tuple space system for the Globus Toolkit using Web services.
{"title":"A Tuple Space Service for Large Scale Infrastructures","authors":"Sirio Capizzi, A. Messina","doi":"10.1109/WETICE.2008.14","DOIUrl":"https://doi.org/10.1109/WETICE.2008.14","url":null,"abstract":"Coordinating tasks is one of the main activities of every grid middleware. There are several ways to achieve this goal, for example using publish/subscribe systems or workflow engines. In this article we will analyse another possible model: tuple spaces. The tuple space model has been successfully used for years for coordinating tasks in computational applications and has interesting characteristics like the support to open systems, allowing an application to scale without the need to reimplement it. This article will describe our experience in developing a tuple space system for the Globus Toolkit using Web services.","PeriodicalId":259447,"journal":{"name":"2008 IEEE 17th Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124841611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Grid Services became a widely used technology for building service oriented applications. The Web service resource framework (WSRF) is the current standard used for building such services as it describes the way to design and communicate with stateful services. However, deploying Web services on a grid environment raises many challenges such as adapting the Web service to the dynamic change of grid resources performance and availability. Therefore, mechanisms, such as service mobility, may be very helpful for supporting autonomic properties of grid services. In this paper, we propose a solution for WSRF grid services strong mobility allowing services to migrate during their execution while keeping their state consistent. In addition, suspended services will resume their execution starting from the interruption point. To show the feasibility of our approach, we present a case study illustrating the application of our transformation on a WSRF Auction service. We provide then some preliminary evaluations performed on the Globus Toolkit (version4.0).
{"title":"Towards Making WSRF Based Web Services Strongly Mobile","authors":"Soumaya Marzouk, M. Jmaiel","doi":"10.1109/WETICE.2008.46","DOIUrl":"https://doi.org/10.1109/WETICE.2008.46","url":null,"abstract":"Grid Services became a widely used technology for building service oriented applications. The Web service resource framework (WSRF) is the current standard used for building such services as it describes the way to design and communicate with stateful services. However, deploying Web services on a grid environment raises many challenges such as adapting the Web service to the dynamic change of grid resources performance and availability. Therefore, mechanisms, such as service mobility, may be very helpful for supporting autonomic properties of grid services. In this paper, we propose a solution for WSRF grid services strong mobility allowing services to migrate during their execution while keeping their state consistent. In addition, suspended services will resume their execution starting from the interruption point. To show the feasibility of our approach, we present a case study illustrating the application of our transformation on a WSRF Auction service. We provide then some preliminary evaluations performed on the Globus Toolkit (version4.0).","PeriodicalId":259447,"journal":{"name":"2008 IEEE 17th Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises","volume":"59 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128270347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Bianchini, V. D. Antonellis, M. Melchiori, Denise Salvi
In recent years, many collaborative organizations started to experience the application of methods and tools for semantic-driven service discovery in a P2P-based cooperation. A critical requirement is the implementation of a dynamic, effective discovery approach in absence of a global view of the shared services. We propose the construction of a service semantic overlay, over the logical network overlay, relating peers that offer similar services by means of inter-peer semantic links. This semantic overlay is properly used to answer a service request against a peer and to apply optimization strategies to forward the request towards suitable competent peers, keeping low the generated network overload. In this paper, we propose a P2P-based Semantic Driven Service Discovery (P2P-SDSD) architectural framework focused on building, maintaining and exploiting the service semantic overlay.
{"title":"Service Discovery for Semantic Peer-to-Peer Cooperation","authors":"D. Bianchini, V. D. Antonellis, M. Melchiori, Denise Salvi","doi":"10.1109/WETICE.2008.18","DOIUrl":"https://doi.org/10.1109/WETICE.2008.18","url":null,"abstract":"In recent years, many collaborative organizations started to experience the application of methods and tools for semantic-driven service discovery in a P2P-based cooperation. A critical requirement is the implementation of a dynamic, effective discovery approach in absence of a global view of the shared services. We propose the construction of a service semantic overlay, over the logical network overlay, relating peers that offer similar services by means of inter-peer semantic links. This semantic overlay is properly used to answer a service request against a peer and to apply optimization strategies to forward the request towards suitable competent peers, keeping low the generated network overload. In this paper, we propose a P2P-based Semantic Driven Service Discovery (P2P-SDSD) architectural framework focused on building, maintaining and exploiting the service semantic overlay.","PeriodicalId":259447,"journal":{"name":"2008 IEEE 17th Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122901496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Micillo, S. Venticinque, N. Mazzocca, Rocco Aversa
Over the last years, service composition has been considered as the main way to enable business-to-business collaborations. Orchestration and choreography are the two main approaches to address service composition. In this paper, we propose a distributed approach for orchestrated execution of complex business processes, in order to enhance the potential of Web Services composition. We present SCOTT, an agent-based Service COmposiTion Tool, and we focus on the execution process of a composite service and on advantages of a decentralized execution engine. Our engine is a peer-to-peer application architecture wherein agents are distributed across multiple computer systems and it appears to its users as a single system.The clever part of this engine are the actuator modules, which collaborate with other ones, in order to execute a complex service in a distributed manner.
{"title":"An Agent-Based Approach for Distributed Execution of Composite Web Services","authors":"R. Micillo, S. Venticinque, N. Mazzocca, Rocco Aversa","doi":"10.1109/WETICE.2008.20","DOIUrl":"https://doi.org/10.1109/WETICE.2008.20","url":null,"abstract":"Over the last years, service composition has been considered as the main way to enable business-to-business collaborations. Orchestration and choreography are the two main approaches to address service composition. In this paper, we propose a distributed approach for orchestrated execution of complex business processes, in order to enhance the potential of Web Services composition. We present SCOTT, an agent-based Service COmposiTion Tool, and we focus on the execution process of a composite service and on advantages of a decentralized execution engine. Our engine is a peer-to-peer application architecture wherein agents are distributed across multiple computer systems and it appears to its users as a single system.The clever part of this engine are the actuator modules, which collaborate with other ones, in order to execute a complex service in a distributed manner.","PeriodicalId":259447,"journal":{"name":"2008 IEEE 17th Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130339995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New collaboration models for software agents can be made more flexible than pre-defined protocols. In pursuit of this, we have used the analysis of human interactions from Dialogue Structure Theory (DST) and devised an agent interaction approach which is based on Task-Based Dialogues (TBDs). This paper describes the following basic constructs of TBDs: a shared task hierarchy to represent agent intentions in the system, a dialogue model that enables agents to construct a meaningful sequence of messages, and a repository of dialogue states. The approach integrates these fundamental ingredients in software agents, and allows agents to implement different strategies in order to achieve their tasks. An example of TBDs shows how a sequence of messages can evolve that is beyond the capability of a single protocol, when the dialogues are driven by shared task specifications and not by a sequence of message types or performatives.
{"title":"Using Task-Based Dialogues for Multi-agent Collaborations","authors":"U. Wajid, N. Mehandjiev","doi":"10.1109/WETICE.2008.38","DOIUrl":"https://doi.org/10.1109/WETICE.2008.38","url":null,"abstract":"New collaboration models for software agents can be made more flexible than pre-defined protocols. In pursuit of this, we have used the analysis of human interactions from Dialogue Structure Theory (DST) and devised an agent interaction approach which is based on Task-Based Dialogues (TBDs). This paper describes the following basic constructs of TBDs: a shared task hierarchy to represent agent intentions in the system, a dialogue model that enables agents to construct a meaningful sequence of messages, and a repository of dialogue states. The approach integrates these fundamental ingredients in software agents, and allows agents to implement different strategies in order to achieve their tasks. An example of TBDs shows how a sequence of messages can evolve that is beyond the capability of a single protocol, when the dialogues are driven by shared task specifications and not by a sequence of message types or performatives.","PeriodicalId":259447,"journal":{"name":"2008 IEEE 17th Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130843493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The 17th edition of the WETICE conference has introduced a special showcase session devoted to promote fruitful discussions on the latest technology developments, directions, problems, and requirements related to projects running in the context of Collaborative Working Environments. This showcase session included both poster presentations and a round table discussion followed by demos and panel exhibition. Seven poster papers have been submitted, and five of them have been accepted for presentation. This report describes the content of accepted posters with the summary of results and products delivered by the relevant projects. We would like to give a special thank to Manfred Bortenschlager and Massimo Mecella for their support to the organization of the showcase session.
{"title":"WETICE2008 Showcase Report","authors":"M. Angelaccio, B. Buttarazzi, A. D’Ambrogio","doi":"10.1109/WETICE.2008.52","DOIUrl":"https://doi.org/10.1109/WETICE.2008.52","url":null,"abstract":"The 17th edition of the WETICE conference has introduced a special showcase session devoted to promote fruitful discussions on the latest technology developments, directions, problems, and requirements related to projects running in the context of Collaborative Working Environments. This showcase session included both poster presentations and a round table discussion followed by demos and panel exhibition. Seven poster papers have been submitted, and five of them have been accepted for presentation. This report describes the content of accepted posters with the summary of results and products delivered by the relevant projects. We would like to give a special thank to Manfred Bortenschlager and Massimo Mecella for their support to the organization of the showcase session.","PeriodicalId":259447,"journal":{"name":"2008 IEEE 17th Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises","volume":"2016 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127482946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：