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ABSTRACT: Trust for the data created and processed on e-Science environment can be estimated with provenance. The information to form provenance, which says how the data was created and reached its current state, increases as data evolves. It is a heavy burden to trace and verify the massive provenance along the history of data in order to trust data. On the other hand, it is another issue how to trust the verification of data with provenance assuming that the provenance is believable. This paper proposes the property-based trust reasoning which cuts down the overhead to track the history and the origin of data with provenance by semantic path on Open Provenance Model(OPM). Also, the domain-based trust reasoning is adopted, which uses the domain specialty of e-Science environment. The two trust reasonings form the multi-layer trust reasoning. The effectiveness of the proposal is shown by quantitative analysis of overhead reduction as well as by qualitative analysis of trust reasoning.
Parallel and Distributed Processing with Applications (ISPA), 2011 IEEE 9th International Symposium on; 06/2011
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ABSTRACT: The design of an end-to-end Internet congestion control protocol that could achieve high utilization, fair sharing of bottleneck bandwidth, and fast convergence while remaining TCP-friendly is an ongoing challenge that continues to attract considerable research attention. This paper presents ACP, an Adaptive end-to-end Congestion control Protocol that achieves the above goals in high bandwidth-delay product networks where TCP becomes inefficient. The main contribution of ACP is a new form of congestion window control, combining the estimation of the bottleneck queue size and a measure of fair sharing. Specifically, upon detecting congestion, ACP decreases the congestion window size by the exact amount required to empty the bottleneck queue while maintaining high utilization, while the increases of the congestion window are based on a “fairness ratio” metric of each flow, which ensures fast convergence to a fair equilibrium. We demonstrate the benefits of ACP using both ns-2 simulation and experimental measurements of a Linux prototype implementation. In particular, we show that the new protocol is TCP-friendly and allows TCP and ACP flows to coexist in various circumstances, and that ACP indeed behaves more fairly than other TCP variants under heterogeneous round-trip times (RTT).
INFOCOM, 2011 Proceedings IEEE; 05/2011
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ABSTRACT: Base platforms for many data-intensive applications start to move onto cloud computing services. These applications inherently requires very large storage space, and append-only distributed file systems have been developed for this purpose. These distributed file systems are capable of running on commodity hardware and highly scalable. Cloud computing service providers only try to reduce management costs, but not concerning about significant up-front investment costs. Additionally, virtual machine technologies, especially Xen that most of cloud computing services use, have low I/O performance. In this paper, we present a cost-effective cloud storage service model, which are built with old PCs but shows good performance. Our experimental evaluation shows 46% better performance in Postmark benchmark.
Advanced Communication Technology (ICACT), 2010 The 12th International Conference on; 03/2010
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ABSTRACT: Recently, REpresentational State Transfer (REST) has been proposed as an alternative architecture for Web services.In the era of Cloud and Web 2.0, many complex Web service-based systems such as e-Business an de-Government applications have adopted REST. Unfortunately, the REST approach has been applied to few cases in management systems, especially for a management system for cloud computing infrastructures.In this paper, we design and implement a RESTful Cloud Management System (CMS).Managed elements can be modeled as resources in REST and operations in existing systems can be evaluated using four methods of REST or a combination of them.We also show how components of existing management systems can be realized as REST-style Web services.
Cloud Computing, 2009. CLOUD '09. IEEE International Conference on; 10/2009
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ABSTRACT: While development of the Internet has contributed to the spread of online education, online exams have not been widely adopted. An online exam is defined here as one that takes place over the insecure Internet, and where no proctor is in the same location as the examinees. This paper proposes an enhanced secure online exam management environment mediated by group cryptography using remote monitoring and control of ports and input. The target domain of this paper is that of online exams for math or English contests in middle or high school, as well as exams in online university courses with students in remote locations.
IEEE Transactions on Education 09/2009; · 1.02 Impact Factor
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ABSTRACT: To provide on-demand video streaming services through the network, video objects with both high and low client request rates must be served efficiently. In this paper, we propose a dynamic scheme transition to provide on-demand streaming services efficiently regardless of video popularity. This approach can maintain quality-of-service (QoS) by transitioning the service scheme according to the request rate. The server provides services by heuristically broadcasting video segments when the video popularity is low and by a periodic broadcast when the video popularity is high. The server identifies the variations in client request rates from the number of service channels and determines transitions to more efficient service schemes autonomously. We evaluated this scheme transition for various parameters and traces from a company providing streaming services. The results show that the performance of scheme transition is very efficient.
IEEE Transactions on Multimedia 05/2009; · 1.93 Impact Factor
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ABSTRACT: Over the past few years much attention has been given to integrating multiple heterogeneous grids. Recently, an adaptor-based grid metascheduler has been proposed as a means to enable interoperation among different grids. However, one drawback of such approach is that when multiple metaschedulers participate in the grid all scheduling instances work in isolation, which in turn leads to poor load-balancing. In this paper, we propose a super-metascheduler approach which improves utilization and removes resource contention by centrally coordinating scheduling processes. Furthermore, it has the benefit of preventing other metaschedulers from disrupting local scheduling-policies because all cross-domain interactions are arbitrated at the super-metascheduler layer.
Advanced Communication Technology, 2009. ICACT 2009. 11th International Conference on; 03/2009
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ABSTRACT: Recently there has arisen concern in both the database community and the graphics society about data retrieval from large motion databases because the high dimensionality of motion data implies high costs. It is a challenging problem to find an effective distance measure and an efficient query processing method for such data. In this paper, we present an elaborate motion query processing system, SMoFinder (Similar Motion Finder), which incorporates a novel kinematic distance measure.
Convergence and Hybrid Information Technology, 2008. ICCIT '08. Third International Conference on; 12/2008
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ABSTRACT: Workflow manager is a useful tool that brings the power of computational grid resources to the desktop, and allow them to conveniently put together and run their own scientific workflows. In existing workflow systems, individual tasks wait for input to be available perform computation, and produce output. Behind this, workflow manager automates the data movement from the data generating task to the data consumption task. This process is referred as file staging. Generally, stage-in, process, and stage-out are serially executed and staging is treated by traditional work- flow systems as a trivial step. However, as the data size is exponentially increasing and more and more scientific workflows require multiple processing steps to obtain the desired output, we argue that the data movement will possess high portion of overall running time and staging will become a challenging step of scientific workflow systems. In this paper, we propose a task pipelining framework for various e-Science workflow systems. Our system is a flexible and efficient tool to help the workflow systems to overlap the execution of adjacent tasks by enabling the pipelining of the intermediate data transfer between the interconnected tasks.
Cluster Computing and the Grid, 2008. CCGRID '08. 8th IEEE International Symposium on; 06/2008
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ABSTRACT: Web Service has its characteristic of statelessness. But, many applications on Grid need the stateful services. The advanced search on HVEM DataGrid is one example. The search service provides a multi-depth search and an associated search. The service should trace the search states and provide the access control as well as the service security in the search process. In addition, we should remember that the Web Services or the resources can stretch multiple Virtual Organization(VO)s and Certificate Authority(CA)s. In this paper, we propose a secure stateful Web Service to satisfy the requirements stated. We describe the Stateful Web Service with the Scalable Security (S3WS) as its service environment and its protocol in detail. Through the security proof, the scalability analysis and the estimation of performance and overhead, we demonstrate the stateful Web Service proposed to be secure and light weight enough to be realistic.
e-Science and Grid Computing, IEEE International Conference on; 01/2008
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ABSTRACT: Building high-performance clusters using one of the two leading network technologies, Myrinet and InfiniBand, has been thought as a de facto way to achieve several teraflops computing power. Meanwhile, maintaining both types of clusters, it appears, may have created an another challenge for the MPI programming system, the most popular parallel programming library that has been successfully used on both networks. The belief that extending cluster resources across two different types of networks may increase computing parallelism has driven many researchers to tackle this challenge with various viewpoints. We approach this challenge with a different perspective, application transparency, which is accomplishing the goal without any modification of legacy MPI applications. We, therefore, focus on the design of an RDMA gateway that can relay messages very fast, and this design focus turns out to be a better way to preserve the application transparency. RDMA gateway (RG), our prototyped system, has a very efficient memory management mechanism that prevents RG from showing irregular spikes of a memory usage under a heavy load condition. Experimental results show that running parallel applications over heterogeneous clusters can be very promising with low performance overhead.
Convergence Information Technology, 2007. International Conference on; 12/2007
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ABSTRACT: Traditional unicast VOD systems require huge amounts of the server network's bandwidth, so near-VOD systems using broadcast protocols have been proposed to reduce the bandwidth requirement. Such systems have not been able to allocate channels dynamically to adapt to environments where the popularity distribution of videos changes, because of the essential inflexibility of existing broadcasting protocols. We address dynamic channel allocation for video broadcasting services, and propose a channel management technique that can adapt well to the dynamic environment, using a flexible broadcasting scheme presented in our previous work (2005). Our channel management scheme decides how many channels should be allocated to each video to maximize the system throughput, based on the video's popularity and reneging probability. The proposed scheme has been verified using extensive simulation.
IEEE Transactions on Consumer Electronics 06/2006; · 0.94 Impact Factor
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ABSTRACT: Advances in network technology and computing power have inspired the emergence of high-performance cluster computing systems. While cluster management and hardware highavailability tools are readily available, practical and easily deployable fault-tolerant systems have not been successfully adopted commercially. We present a fault-tolerant system, Multiple fault-tolerant MPI over Myrinet (M3), that differs in notable respects from other proposed fault-tolerant systems in the literature. M3 is built on top of Myrinet since it is regarded as one of the best solutions for highperformance networks and is widely used in cluster computing systems because it can provide a high-speed switching network that is an inevitable ingredient in interconnecting clusters of workstations or PCs. M^3 is a user-transparent checkpointing system for multiple fault-tolerant MPI implementation that is primarily based on the coordinated checkpointing protocol. M3 supports three critical functionalities that are necessary for faulttolerance: a light-weight failure detection mechanism, dynamic process management that includes process migration, and a consistent checkpoint and recovery mechanism. The features of M are that it requires no modifications of application code and that it preserves much of the high performance characteristics of Myrinet. This paper describes the architecture of M3, its detailed design principles and comprehensive implementation issues. We also propose practical solutions for those involved in constructing highly available cluster systems for parallel programming systems. Experimental results substantiate our assertion that M3 can be a good candidate for practically deployable fault-tolerant systems in very-large and high-performance Myrinet clusters and that its protocol can be applied to a wide variety of parallel communication libraries without difficulty.
Supercomputing, 2005. Proceedings of the ACM/IEEE SC 2005 Conference; 12/2005
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ABSTRACT: In a distributed computing environment, particularly grid, fault-tolerance is one of the core functionalities the system should provide. MPICH-GF is such a resilient system designed to resist external or internal failures, especially for message passing applications in the grid environment. But it does not stand the loss of a valuable resource: files. In a normal case, users open files and write data into them in an asynchronous manner, and checkpointing is initiated with no regard to the state of the context of the process. Therefore, the checkpointing system should automatically recognize the running process and protect the open files transparently. We have implemented a recoverable file system, named ReFS, which is incorporated into our fault-tolerant system MPICH-GF. ReFS is a versioning-like file system. ReFS provides middleware libraries with the system call interface to protect specific files at a given time. This prevents applications from processing their jobs with corrupted data and resulting in incorrect results in case of failures. We have focused not only on the reliability of the system but also on the reduction of inevitable overheads. This paper describes the design and implementation of ReFS and justifies the validity of the behavior of ReFS. We have developed ReFS on Linux, based on Ext2.
Challenges of Large Applications in Distributed Environments, 2005. CLADE 2005. Proceedings; 08/2005
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ABSTRACT: Recently, the distributed agent has become one of the most attractive computing paradigms in the distributed computing community. At the same time, P2P computing has drawn great attention as a new trend in the distributed computing world to achieve the goal of "global resource sharing". Especially, mobile agents with the planning capability can be seen to be a suitable approach to perform tasks efficiently in P2P environment. In this paper, we propose an approach to provide planning capability to the P2P agent system for the better performance. The goal of this approach is two-fold: (1) to present a scalable infrastructure, which integrates the P2P agent system with planning services; and (2) to propose the planning algorithm in order to perform P2P tasks efficiently.
Parallel and Distributed Systems, 2005. Proceedings. 11th International Conference on; 08/2005
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ABSTRACT: The Globus Toolkit makes it very easy and comfortable for grid users to develop and deploy grid services. As for the security mechanism, however, only static authentication and coarse-grained authorization mechanism is provided in current Globus Toolkit. In this paper, we address the limitations of current security mechanism in the Globus Toolkit and propose a new architecture which provides fine-grained and flexible security mechanism which works in dynamic environment. To implement this without modifying existing components, we make use of the aspect-oriented programming technique.
Parallel Processing, 2005. ICPP 2005 Workshops. International Conference Workshops on; 07/2005
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ABSTRACT: A true video-on-demand (TVOD) system lets users view any video program, at any time, and perform any VCR functions, but its per-user video delivery cost is too expensive. A near video-on-demand (NVOD) is a more scalable approach by batching multiple clients to a shared stream or broadcasting videos. In order to provide subscribers with high-quality VOD service, it is desirable to add VCR functionality such as fast forward, fast backward and so on, but the existing video broadcasting, protocols have a limitation on providing VCR functionality. In this paper, we present the conditions necessary to provide VCR functions and then propose a video broadcasting scheme suitable for providing them, which satisfies these conditions, with minimal resource requirements. Since our proposed scheme receives video frames as a unit it can keep up rapidly with a changing VCR action pattern. It is demonstrated that the scheme provides VCR functionality consistently with minimal buffer space through simulations.
IEEE Transactions on Consumer Electronics 12/2003; · 0.94 Impact Factor
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ABSTRACT: Since multizone recording disks have different bandwidths and capacities depending on the zone in use, data placement schemes for traditional constant angular density disks are not suitable for multizone recording disks. In this paper, we propose a new block placement algorithm for multizone recording disks used for continuous media servers. The proposed scheme exploits the bandwidth-saving effect of smoothing variable bit rate data before storing them. The diversity of zone bandwidths in multizone recording disks enables it possible to achieve large smoothing effect using relatively small buffer space. Variable bit rate data blocks of an object are smoothed using multiple smoothing rates which are bandwidths of zones multiplied by the service time assigned to the object and are stored into the corresponding zones. This multirate smoothing technique decreases the buffer space required to provide deterministic service to clients. Simulation results show that a proper restructuring of blocks according to the smoothing algorithm results in dramatic performance enhancement in continuous media servers.
IEEE Transactions on Multimedia 10/2003; · 1.93 Impact Factor
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ABSTRACT: Peer-to-peer (P2P) networks are attracting considerable research interest because of their scalability and high performance relative to cost. One of the important services on a P2P network is the streaming service. However, because each node in the P2P network is autonomous, it is difficult to provide a stable streaming service on the network. Therefore, for a stable streaming service on the P2P network, a fault-tolerant scheme must be provided. In this paper, we propose two new node selection schemes, playback node first (PNF) and playback node first with prefetching (PNF-P), that can be used for a service migration-based fault-tolerant streaming service. The proposed schemes exploit the fact that the failure probability of a node currently being served is lower than that of a node not being served. Simulation results show that the proposed schemes outperform traditional node selection schemes.
Multimedia and Expo, 2003. ICME '03. Proceedings. 2003 International Conference on; 08/2003
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ABSTRACT: The reliable execution of a mobile agent is a very important design issue to build a mobile agent system and many fault-tolerant schemes have been proposed. Hence, we present the experimental evaluation of the performance of the fault-tolerant schemes for the mobile agent environment. Our evaluation focuses on the checkpointing schemes and deals with the cooperating agents.
Dependable Computing, 2002. Proceedings. 2002 Pacific Rim International Symposium on; 01/2003
