The Experts below are selected from a list of 1752 Experts worldwide ranked by ideXlab platform
Tomohide Hasegawa - One of the best experts on this subject based on the ideXlab platform.
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virtage server virtualization with hardware transparency
International Conference on Parallel Processing, 2009Co-Authors: Hitoshi Ueno, Satomi Hasegawa, Tomohide HasegawaAbstract:This paper presents Virtage, Hitachi's virtualization technology, which enables Logical Partitioning of server platforms. Logical Partitioning architecture brings two benefits to this virtualization technology, one is hardware transparency and another is better performance. We first describe its key feature: hardware transparency. With the advantage of hardware transparency for Logical servers, it is possible to provide the same guest Operating System (OS) interface from both physical servers (nonvirtualized servers) and Logical servers. Virtage is hypervisor-type virtualization, and therefore has a natural performance advantage over host-emulation virtualization offerings because guest OSs can be simply and directly executed on the virtualized environment without host intervention. Then we demonstrate this lower overhead for CPU and I/O with performance experiments and explain how Virtage brings mainframe-class virtualization to blade servers. In this paper we study the factors of virtualization overhead for CPU and I/O by using original event monitoring tool that can get hypervisor-event information.
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Euro-Par Workshops - Virtage: Server virtualization with hardware transparency
Lecture Notes in Computer Science, 2009Co-Authors: Hitoshi Ueno, Satomi Hasegawa, Tomohide HasegawaAbstract:This paper presents Virtage, Hitachi's virtualization technology, which enables Logical Partitioning of server platforms. Logical Partitioning architecture brings two benefits to this virtualization technology, one is hardware transparency and another is better performance. We first describe its key feature: hardware transparency. With the advantage of hardware transparency for Logical servers, it is possible to provide the same guest Operating System (OS) interface from both physical servers (nonvirtualized servers) and Logical servers. Virtage is hypervisor-type virtualization, and therefore has a natural performance advantage over host-emulation virtualization offerings because guest OSs can be simply and directly executed on the virtualized environment without host intervention. Then we demonstrate this lower overhead for CPU and I/O with performance experiments and explain how Virtage brings mainframe-class virtualization to blade servers. In this paper we study the factors of virtualization overhead for CPU and I/O by using original event monitoring tool that can get hypervisor-event information.
Hitoshi Ueno - One of the best experts on this subject based on the ideXlab platform.
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virtage server virtualization with hardware transparency
International Conference on Parallel Processing, 2009Co-Authors: Hitoshi Ueno, Satomi Hasegawa, Tomohide HasegawaAbstract:This paper presents Virtage, Hitachi's virtualization technology, which enables Logical Partitioning of server platforms. Logical Partitioning architecture brings two benefits to this virtualization technology, one is hardware transparency and another is better performance. We first describe its key feature: hardware transparency. With the advantage of hardware transparency for Logical servers, it is possible to provide the same guest Operating System (OS) interface from both physical servers (nonvirtualized servers) and Logical servers. Virtage is hypervisor-type virtualization, and therefore has a natural performance advantage over host-emulation virtualization offerings because guest OSs can be simply and directly executed on the virtualized environment without host intervention. Then we demonstrate this lower overhead for CPU and I/O with performance experiments and explain how Virtage brings mainframe-class virtualization to blade servers. In this paper we study the factors of virtualization overhead for CPU and I/O by using original event monitoring tool that can get hypervisor-event information.
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Euro-Par Workshops - Virtage: Server virtualization with hardware transparency
Lecture Notes in Computer Science, 2009Co-Authors: Hitoshi Ueno, Satomi Hasegawa, Tomohide HasegawaAbstract:This paper presents Virtage, Hitachi's virtualization technology, which enables Logical Partitioning of server platforms. Logical Partitioning architecture brings two benefits to this virtualization technology, one is hardware transparency and another is better performance. We first describe its key feature: hardware transparency. With the advantage of hardware transparency for Logical servers, it is possible to provide the same guest Operating System (OS) interface from both physical servers (nonvirtualized servers) and Logical servers. Virtage is hypervisor-type virtualization, and therefore has a natural performance advantage over host-emulation virtualization offerings because guest OSs can be simply and directly executed on the virtualized environment without host intervention. Then we demonstrate this lower overhead for CPU and I/O with performance experiments and explain how Virtage brings mainframe-class virtualization to blade servers. In this paper we study the factors of virtualization overhead for CPU and I/O by using original event monitoring tool that can get hypervisor-event information.
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GPC Workshops - Virtage: Hitachi's Virtualization Technology
2009 Workshops at the Grid and Pervasive Computing Conference, 2009Co-Authors: Hitoshi Ueno, Satomi HasegawaAbstract:This paper presents Virtage, Hitachi’s virtualization technology, which enables Logical Partitioning of server platforms. We describe its key feature: hardware transparency. With the advantage of hardware transparency for Logical servers, it is possible to provide the same guest Operating System (OS) interface from both physical servers (non-virtualized servers) and Logical servers. Virtage is hypervisor-type virtualization, and therefore has a natural performance advantage over host-emulation virtualization offerings because guest OSs can be simply and directly executed on the virtualized environment without host intervention. We demonstrate this lower overhead with performance experiments and explain how Virtage brings mainframe-class virtualization to blade servers.
Pallab Dasgupta - One of the best experts on this subject based on the ideXlab platform.
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ICISTM - A Spatio-Temporal Role-Based Access Control Model for Wireless LAN Security Policy Management
Information Systems Technology and Management, 2010Co-Authors: Padmalochan Bera, Soumya K. Ghosh, Pallab DasguptaAbstract:The widespread proliferation of wireless networks (WLAN) has opened up new paradigms of security policy management in enterprise networks. To enforce the organizational security policies in wireless local area networks (WLANs), it is required to protect the network resources from unauthorized access. In WLAN security policy management, the standard IP based access control mechanisms are not sufficient to meet the organizational requirements due to its dynamic topology characteristics. In such dynamic network environments, the role-based access control (RBAC) mechanisms can be deployed to strengthen the security perimeter over the network resources. Further, there is a need to incorporate time and location dependent constraints in the access control models. In this paper, we propose a WLAN security management system which supports a spatio-temporal RBAC (STRBAC) model. The system stems from Logical Partitioning of the WLAN topology into various security policy zones. It includes a Global Policy Server (GPS) that formalizes the organizational access policies and determines the high level policy configurations for different policy zones; a Central Authentication & Role Server (CARS) which authenticates the users (or nodes) and the access points (AP) in various zones and also assigns appropriate roles to the users. Each policy zone consists of an Wireless Policy Zone Controller (WPZCon) that co-ordinates with a dedicated Local Role Server (LRS) to extract the low level access configurations corresponding to the zone access points. We also propose a formal spatio-temporal RBAC (STRBAC) model to represent the security policies formally.
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CNSA - A SAT Based Verification Framework for Wireless LAN Security Policy Management Supported by STRBAC Model
Recent Trends in Network Security and Applications, 2010Co-Authors: Padmalochan Bera, Soumya K. Ghosh, Soumya Maity, Pallab DasguptaAbstract:The widespread proliferation of wireless networks (WLAN) demands formal evaluation and analysis of security policy management in enterprise networks. The enforcement of organizational security policies in wireless local area networks (WLANs) requires protection over the network resources from unauthorized access. Hence it is required to ensure correct distribution of access control rules to the network access points conforming to the security policy. In WLAN security policy management, the role-based access control (RBAC) mechanisms can be deployed to strengthen the security perimeter over the network resources. Further, there is a need to model the time and location dependent access constraints. In this paper, we propose WLAN security management system supported by a spatio-temporal RBAC (STRBAC) model and a SAT based verification framework. The system stems from Logical Partitioning of the WLAN topology into various security policy zones. It includes a Global Policy Server (GPS) that formalizes the organizational access policies and determines the high level policy configurations; a Central Authentication & Role Server (CARS) which authenticates the users and the access points (AP) in various zones and also assigns appropriate roles to the users. Each policy zone consists of an Wireless Policy Zone Controller (WPZCon) that co-ordinates with a dedicated Local Role Server (LRS) to extract the low level access configurations corresponding to the zone access router. We also propose a formal spatio-temporal RBAC (STRBAC) model to represent the global security policies formally and a SAT based verification framework to verify the access configurations.
Satomi Hasegawa - One of the best experts on this subject based on the ideXlab platform.
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virtage server virtualization with hardware transparency
International Conference on Parallel Processing, 2009Co-Authors: Hitoshi Ueno, Satomi Hasegawa, Tomohide HasegawaAbstract:This paper presents Virtage, Hitachi's virtualization technology, which enables Logical Partitioning of server platforms. Logical Partitioning architecture brings two benefits to this virtualization technology, one is hardware transparency and another is better performance. We first describe its key feature: hardware transparency. With the advantage of hardware transparency for Logical servers, it is possible to provide the same guest Operating System (OS) interface from both physical servers (nonvirtualized servers) and Logical servers. Virtage is hypervisor-type virtualization, and therefore has a natural performance advantage over host-emulation virtualization offerings because guest OSs can be simply and directly executed on the virtualized environment without host intervention. Then we demonstrate this lower overhead for CPU and I/O with performance experiments and explain how Virtage brings mainframe-class virtualization to blade servers. In this paper we study the factors of virtualization overhead for CPU and I/O by using original event monitoring tool that can get hypervisor-event information.
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Euro-Par Workshops - Virtage: Server virtualization with hardware transparency
Lecture Notes in Computer Science, 2009Co-Authors: Hitoshi Ueno, Satomi Hasegawa, Tomohide HasegawaAbstract:This paper presents Virtage, Hitachi's virtualization technology, which enables Logical Partitioning of server platforms. Logical Partitioning architecture brings two benefits to this virtualization technology, one is hardware transparency and another is better performance. We first describe its key feature: hardware transparency. With the advantage of hardware transparency for Logical servers, it is possible to provide the same guest Operating System (OS) interface from both physical servers (nonvirtualized servers) and Logical servers. Virtage is hypervisor-type virtualization, and therefore has a natural performance advantage over host-emulation virtualization offerings because guest OSs can be simply and directly executed on the virtualized environment without host intervention. Then we demonstrate this lower overhead for CPU and I/O with performance experiments and explain how Virtage brings mainframe-class virtualization to blade servers. In this paper we study the factors of virtualization overhead for CPU and I/O by using original event monitoring tool that can get hypervisor-event information.
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GPC Workshops - Virtage: Hitachi's Virtualization Technology
2009 Workshops at the Grid and Pervasive Computing Conference, 2009Co-Authors: Hitoshi Ueno, Satomi HasegawaAbstract:This paper presents Virtage, Hitachi’s virtualization technology, which enables Logical Partitioning of server platforms. We describe its key feature: hardware transparency. With the advantage of hardware transparency for Logical servers, it is possible to provide the same guest Operating System (OS) interface from both physical servers (non-virtualized servers) and Logical servers. Virtage is hypervisor-type virtualization, and therefore has a natural performance advantage over host-emulation virtualization offerings because guest OSs can be simply and directly executed on the virtualized environment without host intervention. We demonstrate this lower overhead with performance experiments and explain how Virtage brings mainframe-class virtualization to blade servers.
Theo Härder - One of the best experts on this subject based on the ideXlab platform.
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ICDE - Dynamic physioLogical Partitioning on a shared-nothing database cluster
2015 IEEE 31st International Conference on Data Engineering, 2015Co-Authors: Daniel Schall, Theo HärderAbstract:Traditional database management systems (DBMSs) running on powerful single-node servers are usually over-provisioned for most of their daily workloads and, because they do not show good-enough energy proportionality, waste a lot of energy while underutilized. A cluster of small (wimpy) servers, where its size can be dynamically adjusted to the current workload, offers better energy characteristics for those workloads. Yet, data migration, necessary to balance utilization among the nodes, is a non-trivial and time-consuming task that may consume the energy saved. For this reason, a sophisticated and easy to adjust Partitioning scheme fostering dynamic reorganization is needed. In this paper, we adapt a technique originally created for SMP systems, called physioLogical Partitioning, to distribute data among nodes that allows to easily repartition data without interrupting transactions. We dynamically partition DB tables based on the nodes' utilization and given energy constraints and compare our approach with physical Partitioning and Logical Partitioning methods. To quantify possible energy saving and its conceivable drawback on query runtimes, we evaluate our implementation on an experimental cluster and compare the results w.r.t. performance and energy consumption. Depending on the workload, we can substantially save energy without sacrificing too much performance.
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Dynamic PhysioLogical Partitioning on a Shared-nothing Database Cluster
arXiv: Databases, 2014Co-Authors: Daniel Schall, Theo HärderAbstract:Traditional DBMS servers are usually over-provisioned for most of their daily workloads and, because they do not show good-enough energy proportionality, waste a lot of energy while underutilized. A cluster of small (wimpy) servers, where its size can be dynamically adjusted to the current workload, offers better energy characteristics for these workloads. Yet, data migration, necessary to balance utilization among the nodes, is a non-trivial and time-consuming task that may consume the energy saved. For this reason, a sophisticated and easy to adjust Partitioning scheme fostering dynamic reorganization is needed. In this paper, we adapt a technique originally created for SMP systems, called physioLogical Partitioning, to distribute data among nodes, that allows to easily repartition data without interrupting transactions. We dynamically partition DB tables based on the nodes' utilization and given energy constraints and compare our approach with physical Partitioning and Logical Partitioning methods. To quantify possible energy saving and its conceivable drawback on query runtimes, we evaluate our implementation on an experimental cluster and compare the results w.r.t. performance and energy consumption. Depending on the workload, we can substantially save energy without sacrificing too much performance.
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Exploiting abstraction relationships' semantics for transaction synchronization in KBMSs
Data & Knowledge Engineering, 1997Co-Authors: Fernando De Ferreira Rezende, Theo HärderAbstract:Abstract Currently, knowledge sharing is turning out to be a crucial area that needs to be supported by Knowledge Base Management Systems (KBMSs). We propose an approach for transaction synchronization in KBMSs-LARS (Locks using Abstraction Relationships' Semantics). We show how we obtain serializability of transactions thereby providing different locking granules. The main benefit of our technique is the high degree of potential concurrency, which is obtained by means of a Logical Partitioning of the knowledge base (KB) grounded in the abstraction relationships, and the provision of many lock types to be used on the basis of each partition. In this way, we capture the abstraction relationships' semantics which are contained in a KB graph for transaction synchronization purposes and enable the exploitation of the inherent parallelism in a knowledge representation approach.
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CIKM - A lock method for KBMSs using abstraction relationships' semantics
Proceedings of the third international conference on Information and knowledge management - CIKM '94, 1994Co-Authors: Fernando De Ferreira Rezende, Theo HärderAbstract:Knowledge Base Management Systems (KBMSs) are a growing research area finding applicability in different domains. As a consequence, the demand for ever-larger knowledge bases (KBs) is growing more and more. Inside this context, knowledge sharing turns out to be a crucial point to be supported by KBMSs. In this paper, we propose a way of controlling knowledge sharing. We show how we obtain serializability of transactions providing many different locking granules, which are based on the semantics of the abstraction relationships. The main benefit of our technique is the high degree of potential concurrency, to be obtained through a Logical Partitioning of the KB graph and the provision of lock types used for each referenced partition. By this way, we capture more of the semantics contained in a KB graph, through an interpretation of its edges grounded in the abstraction relationships, and make feasible a full exploitation of all inherent parallelism in a knowledge representation approach.
