The Experts below are selected from a list of 7422 Experts worldwide ranked by ideXlab platform

Toshitsugu Yuba - One of the best experts on this subject based on the ideXlab platform.

  • PPAM - Evaluation of the acknowledgment reduction in a Software-DSM system
    Parallel Processing and Applied Mathematics, 2006
    Co-Authors: Kenji Kise, Takahiro Katagiri, Hiroki Honda, Toshitsugu Yuba
    Abstract:

    We discuss the inter-process communication in software distributed shared memory (S-DSM) systems. Some S-DSM systems, such as TreadMarks and JIAJIA, adopt the user datagram protocol (UDP) which does not provide the reliable communication between the computation nodes. To detect a communication error and recover from it, therefore, an acknowledgment is used for every message transmission in the Middleware Layer. In this paper, first, we show that an acknowledgment is not necessarily required for each message transmission in the Middleware Layer. Second, a method to reduce the acknowledgment overhead for a page request is proposed. We implemented the proposed method in our S-DSM system Mocha. The performance of the method was measured with several benchmark programs on both a PC cluster and an SMP cluster.

  • Evaluation of the acknowledgment reduction in a software-DSM system
    Lecture Notes in Computer Science, 2006
    Co-Authors: Kenji Kise, Takahiro Katagiri, Hiroki Honda, Toshitsugu Yuba
    Abstract:

    We discuss the inter-process communication in software distributed shared memory (S-DSM) systems. Some S-DSM systems, such as TreadMarks and JIAJIA, adopt the user datagram protocol (UDP) which does not provide the reliable communication between the computation nodes. To detect a communication error and recover from it, therefore, an acknowledgment is used for every message transmission in the Middleware Layer. In this paper, first, we show that an acknowledgment is not necessarily required for each message transmission in the Middleware Layer. Second, a method to reduce the acknowledgment overhead for a page request is proposed. We implemented the proposed method in our S-DSM system Mocha. The performance of the method was measured with several benchmark programs on both a PC cluster and an SMP cluster.

  • A Method to Reduce the Acknowledgement Overhead of S-DSM Systems
    2005
    Co-Authors: Kenji Kise, Takahiro Katagiri, Hiroki Honda, Toshitsugu Yuba
    Abstract:

    We discuss the inter-process communication in software distributed shared memory (S-DSM) systems. Some S-DSM systems, such as TreadMarks and JIAJIA, adopt the user datagram protocol (UDP) which does not provide the reliable communication between the computation nodes. To detect and recover from a communication error, therefore, an acknowledgment (ACK) is used for every message transmission in the Middleware Layer. In this paper, firstly, we show that an acknowledgement is not necessarily required per one message transmission in the Middleware Layer. Secondly, the method to reduce the acknowledgement overhead for a page request is proposed. We implemented the proposed method in our S-DSM system Mocha. The performance of the method was measured with several benchmark programs. We show that Matrix Multiply (MM) of high page transfer frequency achieves a drastic speedup as much as 92% for a 16-node PC cluster, compared with the conventional communication method of not omitting the acknowledgment.

Jing Pang - One of the best experts on this subject based on the ideXlab platform.

  • a design of Middleware Layer for qos in wireless sensor networks
    International Conference on Parallel and Distributed Systems, 2012
    Co-Authors: Zhenhui Cui, Ting Yang, Jing Pang
    Abstract:

    Based on the characteristics of the wireless sensor networks, a Middleware Layer for quality of service support was proposed. For kinds of user's QoS requirements, tasks of network were scheduled by collecting and updating local information continuously, and the reliability of network was enhanced by redundancy. Results of simulation show that the Middleware mechanism can not only meet the user QoS requirements, but also reduce the energy consumption of network.

  • ICPADS - A Design of Middleware Layer for QoS in Wireless Sensor Networks
    2012 IEEE 18th International Conference on Parallel and Distributed Systems, 2012
    Co-Authors: Zhenhui Cui, Ting Yang, Jing Pang
    Abstract:

    Based on the characteristics of the wireless sensor networks, a Middleware Layer for quality of service support was proposed. For kinds of user's QoS requirements, tasks of network were scheduled by collecting and updating local information continuously, and the reliability of network was enhanced by redundancy. Results of simulation show that the Middleware mechanism can not only meet the user QoS requirements, but also reduce the energy consumption of network.

Maarten Van Steen - One of the best experts on this subject based on the ideXlab platform.

  • a flexible Middleware Layer for user to user messaging
    Distributed Applications and Interoperable Systems, 2003
    Co-Authors: Janmark S Wams, Maarten Van Steen
    Abstract:

    There is growing trend to unify user-to-user messaging systems to allow message exchange, independent of time, place, protocol, and end-user device. Building gateways to interconnect existing messaging systems seems an obvious approach to unification. In this paper we argue that unification should take place at the level of the underlying messaging models. Such a unification results in one messaging model that has maximum adaptability, allowing one system to deliver the same messaging services that all currently existing messaging systems deliver, as well as hitherto impossible mixes of those services.

  • a flexible Middleware Layer for user to user messaging
    Lecture Notes in Computer Science, 2003
    Co-Authors: Janmark S Wams, Maarten Van Steen
    Abstract:

    There is growing trend to unify user-to-user messaging systems to allow message exchange, independent of time, place, protocol, and end-user device. Building gateways to interconnect existing messaging systems seems an obvious approach to unification. In this paper we argue that unification should take place at the level of the underlying messaging models. Such a unification results in one messaging model that has maximum adaptability, allowing one system to deliver the same messaging services that all currently existing messaging systems deliver, as well as hitherto impossible mixes of those services. We present a novel unified messaging model that supports maximum adaptability. Our approach supports the same services that all current messaging models support, including those of e-mail, fax, SMS, ICQ, i-mail, USENET News, AIM, blog, MMS, and voicemail. To substantiate the claim that such a unified model can be implemented efficiently on a worldwide scale, we present the design of an accompanying highly adaptable and scalable messaging Middleware system.

Kenji Kise - One of the best experts on this subject based on the ideXlab platform.

  • PPAM - Evaluation of the acknowledgment reduction in a Software-DSM system
    Parallel Processing and Applied Mathematics, 2006
    Co-Authors: Kenji Kise, Takahiro Katagiri, Hiroki Honda, Toshitsugu Yuba
    Abstract:

    We discuss the inter-process communication in software distributed shared memory (S-DSM) systems. Some S-DSM systems, such as TreadMarks and JIAJIA, adopt the user datagram protocol (UDP) which does not provide the reliable communication between the computation nodes. To detect a communication error and recover from it, therefore, an acknowledgment is used for every message transmission in the Middleware Layer. In this paper, first, we show that an acknowledgment is not necessarily required for each message transmission in the Middleware Layer. Second, a method to reduce the acknowledgment overhead for a page request is proposed. We implemented the proposed method in our S-DSM system Mocha. The performance of the method was measured with several benchmark programs on both a PC cluster and an SMP cluster.

  • Evaluation of the acknowledgment reduction in a software-DSM system
    Lecture Notes in Computer Science, 2006
    Co-Authors: Kenji Kise, Takahiro Katagiri, Hiroki Honda, Toshitsugu Yuba
    Abstract:

    We discuss the inter-process communication in software distributed shared memory (S-DSM) systems. Some S-DSM systems, such as TreadMarks and JIAJIA, adopt the user datagram protocol (UDP) which does not provide the reliable communication between the computation nodes. To detect a communication error and recover from it, therefore, an acknowledgment is used for every message transmission in the Middleware Layer. In this paper, first, we show that an acknowledgment is not necessarily required for each message transmission in the Middleware Layer. Second, a method to reduce the acknowledgment overhead for a page request is proposed. We implemented the proposed method in our S-DSM system Mocha. The performance of the method was measured with several benchmark programs on both a PC cluster and an SMP cluster.

  • A Method to Reduce the Acknowledgement Overhead of S-DSM Systems
    2005
    Co-Authors: Kenji Kise, Takahiro Katagiri, Hiroki Honda, Toshitsugu Yuba
    Abstract:

    We discuss the inter-process communication in software distributed shared memory (S-DSM) systems. Some S-DSM systems, such as TreadMarks and JIAJIA, adopt the user datagram protocol (UDP) which does not provide the reliable communication between the computation nodes. To detect and recover from a communication error, therefore, an acknowledgment (ACK) is used for every message transmission in the Middleware Layer. In this paper, firstly, we show that an acknowledgement is not necessarily required per one message transmission in the Middleware Layer. Secondly, the method to reduce the acknowledgement overhead for a page request is proposed. We implemented the proposed method in our S-DSM system Mocha. The performance of the method was measured with several benchmark programs. We show that Matrix Multiply (MM) of high page transfer frequency achieves a drastic speedup as much as 92% for a 16-node PC cluster, compared with the conventional communication method of not omitting the acknowledgment.

Valerie Issarny - One of the best experts on this subject based on the ideXlab platform.

  • Automated synthesis of mediators for Middleware-Layer protocol interoperability in the IoT
    Future Generation Computer Systems, 2019
    Co-Authors: Georgios Bouloukakis, Nikolaos Georgantas, Patient Ntumba, Valerie Issarny
    Abstract:

    To enable direct Internet connectivity of Things, complete protocol stacks need to be deployed on resource-constrained devices. Such protocol stacks typically build on lightweight IPv6 adaptations and may even include a Middleware Layer supporting high-level application development. However, the profusion of IoT Middleware-Layer interaction protocols has introduced technology diversity and high fragmentation in the IoT systems landscape with siloed vertical solutions. To enable the interconnection of heterogeneous Things across these barriers, advanced interoperability solutions at the Middleware Layer are required. In this paper, we introduce a solution for the automated synthesis of protocol mediators that support the interconnection of heterogeneous Things. Our systematic approach relies on the Data eXchange (DeX) connector model, which comprehensively abstracts and represents existing and potentially future IoT Middleware protocols. Thanks to DeX, Things seamlessly interconnect through lightweight mediators. We validate our solution with respect to: (i) the support to developers when developing heterogeneous IoT applications; (ii) the runtime performance of the synthesized mediators.

  • Reasoning about and Harmonizing the Interaction Behavior of Networked Systems at Application- and Middleware- Layer
    2011
    Co-Authors: Amel Bennaceur, Paola Inverardi, Franck Chauvel, Valerie Issarny, Ilaria Matteucci, Fabio Martinelli, Romina Spalazzese, Massimo Tivoli
    Abstract:

    The CONNECT Integrated Project aims at enabling continuous composition of networked systems to respond to the evolution of functionalities provided to and required from the networked environment. CONNECT aims at dropping the interoperability barrier by adopting a revolutionary approach to the seamless networking of digital systems, that is, synthesizing on-the-fly the connectors via which networked systems communicate. The resulting emergent connectors are effectively synthesized according to the behavioral semantics of application- down to Middleware-Layer protocols run by the interacting parties. The role of work package WP3 is to devise automated and compositional approaches to connector synthesis, which can be performed at run-time. Given the respective interaction behavior of networked systems, we want to synthesize the behavior of the connector(s) needed for them to interact. These connectors serve as mediators of the networked systems' interaction at both application and Middleware Layers. During the project's first year, the work of WP3 led us to achieve the following preliminary results: the formalization of matching and mapping relationships for application-Layer interaction protocols; the definition of the corresponding mediator generation algorithm; the analysis of the interoperability problems, and related solutions, that can occur at Middleware-Layer; and a model-driven approach to the automated elicitation of application-Layer protocols from software implementations. All these achievements have been reported in Deliverable D3.1: "Modeling of application- and Middleware-Layer interaction protocols". In this deliverable, we go a step forward with respect to some of the previous achievements by delivering a unified process, and related artefacts, for the automated synthesis of mediators at both application and Middleware Layers, code-generation techniques to generate the actual code that implements a synthesized mediator, and a preliminary integration of QoS management in the synthesis process. During year 2, all the work has been validated through its application to several scenarios, in particular as part of WP1 and WP6. By selecting one of them as common scenario, in this deliverable, we also show the different methods/techniques at work on the scenario. All the steps of the devised synthesis process are described in detail and applied to the selected common scenario.

  • Middleware-Layer Connector Synthesis: Beyond State of the Art in Middleware Interoperability
    2011
    Co-Authors: Valerie Issarny, Amel Bennaceur, Yérom-david Bromberg
    Abstract:

    This chapter deals with interoperability among pervasive networked systems, in particular accounting for the heterogeneity of protocols from the application down to the Middleware Layer, which is mandatory for today's and even more for tomorrow's open and highly heterogeneous networks. The chapter then surveys existing approaches to Middleware interoperability, further providing a formal specification so as to allow for rigorous characterization and assessment. In general, existing approaches fail to address interoperability required by today's ubiquitous and heterogeneous networking environments where interaction protocols run by networked systems need to be mediated at both application and Middleware Layers. To meet such a goal, this chapter introduces the approach that is investigated within the Connect project and that deals with the dynamic synthesis of emergent connectors that mediate the interaction protocols executed by the networked systems.

  • SFM - Middleware-Layer Connector Synthesis: Beyond State of the Art in Middleware Interoperability
    Formal Methods for Eternal Networked Software Systems, 2011
    Co-Authors: Valerie Issarny, Amel Bennaceur, Yérom-david Bromberg
    Abstract:

    This chapter deals with interoperability among pervasive networked systems, in particular accounting for the heterogeneity of protocols from the application down to the Middleware Layer, which is mandatory for today's and even more for tomorrow's open and highly heterogeneous networks. The chapter then surveys existing approaches to Middleware interoperability, further providing a formal specification so as to allow for rigorous characterization and assessment. In general, existing approaches fail to address interoperability required by today's ubiquitous and heterogeneous networking environments where interaction protocols run by networked systems need to be mediated at both application and Middleware Layers. To meet such a goal, this chapter introduces the approach that is investigated within the Connect project and that deals with the dynamic synthesis of emergent connectors that mediate the interaction protocols executed by the networked systems.

  • Modeling of application- and Middleware-Layer interaction protocols
    2010
    Co-Authors: Amel Bennaceur, Paola Inverardi, Valerie Issarny, Antonia Bertolino, Paul Grace, Massimo Tivoli
    Abstract:

    The CONNECT Integrated Project aims at enabling continuous composition of networked systems to respond to the evolution of functionalities provided to and required from the networked environment. CONNECT aims at dropping the interoperability barrier by adopting a revolutionary approach to the seamless networking of digital systems, that is, synthesizing on-the-fly the connectors via which networked systems communicate. The resulting emergent connectors are effectively synthesized according to the behavioral semantics of application- down to Middleware-Layer protocols run by the interacting parties. The role of work package WP3 is to devise automated and compositional approaches to connector synthesis, which can be performed at run-time. Given the respective interaction behavior of networked systems, we want to synthesize the behavior of the connector(s) needed for them to interact. These connectors serve as mediators of the networked systems' interaction at both application and Middleware Layers. In this deliverable, we set the scene for a formal theory of the automated synthesis of application- and Middleware-Layer protocol mediators. We formally characterize mediating connectors between mismatching application-Layer protocols by rigorously defining the necessary conditions that must hold for protocols to be mediated. The outcome of this formalization is the definition of two relationships between heterogenous protocols: matching and mapping. The former is concerned with checking whether a mediator letting two protocols interoperate exists or not. The latter concerns the algorithm that should be executed to synthesize the required mediator. Furthermore, we analyze the different dimensions of interoperability at the Middleware Layer and exploit this analysis to formalize existing solutions to Middleware-Layer interoperability. Since the work on application-Layer mediator synthesis is based on the assumption that a model of the interaction protocol for a networked system is dynamically discovered, we finally present an approach, based on data-flow analysis and testing, for the automated elicitation of application-Layer protocols from software implementations. This approach presents similarities, but also several differences, with the work of work package WP4 (protocol learning). Furthermore, it allowed us to proceed in parallel with the work of WP4 and to state the requirements that the learning approaches have to satisfy to enable mediator synthesis. For this reason, we keep this work separate from the work on protocol learning and discuss it in this deliverable. All the approaches mentioned above are applied to several examples and scenarios.