%0 Conference Paper %B IEEE 25th International Conference on Data Engineering, 2009. ICDE '09 %D 2009 %T Web Monitoring 2.0: Crossing Streams to Satisfy Complex Data Needs %A Roitman,H. %A Gal,A. %A Raschid, Louiqa %K Bandwidth %K complex client information need %K Data Delivery %K Data engineering %K database management systems %K Educational institutions %K Internet %K Mashups %K mashups generation %K Monitoring %K multiple information source %K offline algorithmic solution %K Portals %K PROBES %K Profiles %K Query processing %K scalability %K scheduling %K volatile information stream %K Web 2.0 %K Web Monitoring %X Web monitoring 2.0 supports the complex information needs of clients who probe multiple information sources and generate mashups by integrating across these volatile streams. A proxy that aims at satisfying multiple customized client profiles will face a scalability challenge in trying to maximize the number of clients served while at the same time fully satisfying complex client needs. In this paper, we introduce an abstraction of complex execution intervals, a combination of time intervals and information streams, to capture complex client needs. Given some budgetary constraints (e.g., bandwidth), we present offline algorithmic solutions for the problem of maximizing completeness of capturing complex profiles. %B IEEE 25th International Conference on Data Engineering, 2009. ICDE '09 %I IEEE %P 1215 - 1218 %8 2009/04/29/March %@ 978-1-4244-3422-0 %G eng %R 10.1109/ICDE.2009.204 %0 Journal Article %J SIGCOMM Comput. Commun. Rev. %D 2008 %T Accountable internet protocol (aip) %A Andersen,David G. %A Balakrishnan,Hari %A Feamster, Nick %A Koponen,Teemu %A Moon,Daekyeong %A Shenker,Scott %K accountability %K address %K internet architecture %K scalability %K Security %X This paper presents AIP (Accountable Internet Protocol), a network architecture that provides accountability as a first-order property. AIP uses a hierarchy of self-certifying addresses, in which each component is derived from the public key of the corresponding entity. We discuss how AIP enables simple solutions to source spoofing, denial-of-service, route hijacking, and route forgery. We also discuss how AIP's design meets the challenges of scaling, key management, and traffic engineering. %B SIGCOMM Comput. Commun. Rev. %V 38 %P 339 - 350 %8 2008/08// %@ 0146-4833 %G eng %U http://doi.acm.org/10.1145/1402946.1402997 %N 4 %R 10.1145/1402946.1402997 %0 Conference Paper %B Proceedings of the 2008 ACM SIGMOD international conference on Management of data %D 2008 %T Scalable network distance browsing in spatial databases %A Samet, Hanan %A Sankaranarayanan,Jagan %A Alborzi,Houman %K decoupling %K nearest neighbor %K scalability %K shortest path quadtree %K spatial networks %X An algorithm is presented for finding the k nearest neighbors in a spatial network in a best-first manner using network distance. The algorithm is based on precomputing the shortest paths between all possible vertices in the network and then making use of an encoding that takes advantage of the fact that the shortest paths from vertex u to all of the remaining vertices can be decomposed into subsets based on the first edges on the shortest paths to them from u. Thus, in the worst case, the amount of work depends on the number of objects that are examined and the number of links on the shortest paths to them from q, rather than depending on the number of vertices in the network. The amount of storage required to keep track of the subsets is reduced by taking advantage of their spatial coherence which is captured by the aid of a shortest path quadtree. In particular, experiments on a number of large road networks as well as a theoretical analysis have shown that the storage has been reduced from O(N3) to O(N1.5) (i.e., by an order of magnitude equal to the square root). The precomputation of the shortest paths along the network essentially decouples the process of computing shortest paths along the network from that of finding the neighbors, and thereby also decouples the domain S of the query objects and that of the objects from which the neighbors are drawn from the domain V of the vertices of the spatial network. This means that as long as the spatial network is unchanged, the algorithm and underlying representation of the shortest paths in the spatial network can be used with different sets of objects. %B Proceedings of the 2008 ACM SIGMOD international conference on Management of data %S SIGMOD '08 %I ACM %C New York, NY, USA %P 43 - 54 %8 2008/// %@ 978-1-60558-102-6 %G eng %U http://doi.acm.org/10.1145/1376616.1376623 %R 10.1145/1376616.1376623 %0 Journal Article %J IEEE Transactions on Visualization and Computer Graphics %D 2006 %T Network Visualization by Semantic Substrates %A Shneiderman, Ben %A Aris,A. %K Automatic control %K data visualisation %K Data visualization %K Displays %K Filters %K Graphical user interfaces %K Information Visualization %K information visualization designers %K Law %K legal citations %K Legal factors %K legal precedent data %K network visualization %K NVSS 1.0 %K scalability %K semantic substrate %K Terminology %K Tunneling %K user-defined semantic substrates %X Networks have remained a challenge for information visualization designers because of the complex issues of node and link layout coupled with the rich set of tasks that users present. This paper offers a strategy based on two principles: (1) layouts are based on user-defined semantic substrates, which are non-overlapping regions in which node placement is based on node attributes, (2) users interactively adjust sliders to control link visibility to limit clutter and thus ensure comprehensibility of source and destination. Scalability is further facilitated by user control of which nodes are visible. We illustrate our semantic substrates approach as implemented in NVSS 1.0 with legal precedent data for up to 1122 court cases in three regions with 7645 legal citations %B IEEE Transactions on Visualization and Computer Graphics %V 12 %P 733 - 740 %8 2006/10//Sept %@ 1077-2626 %G eng %N 5 %R 10.1109/TVCG.2006.166 %0 Journal Article %J Circuits and Systems for Video Technology, IEEE Transactions on %D 2005 %T Efficient bandwidth resource allocation for low-delay multiuser video streaming %A Su,Guan-Ming %A M. Wu %K algorithm; %K allocation %K allocation; %K approaches; %K average %K Bandwidth %K channel %K channels; %K coding; %K complexity; %K computational %K control; %K distortion; %K dynamic %K efficient %K fine %K fluctuation; %K granularity %K look-ahead %K low-delay %K MPEG-4 %K multiple %K multiuser %K QUALITY %K quality; %K rate-control %K resource %K scalability %K scenario; %K single-user %K sliding-window %K streaming; %K Telecommunication %K utilization; %K video %K visual %X This paper studies efficient bandwidth resource allocation for streaming multiple MPEG-4 fine granularity scalability (FGS) video programs to multiple users. We begin with a simple single-user scenario and propose a rate-control algorithm that has low delay and achieves an excellent tradeoff between the average visual distortion and the quality fluctuation. The proposed algorithm employs two weight factors for adjusting the tradeoff, and the optimal choice of these factors is derived. We then extend to the multiuser case and propose a dynamic resource allocation algorithm with low delay and low computational complexity. By exploring the variations in the scene complexity of video programs as well as dynamically and jointly distributing the available system resources among users, our proposed algorithm provides low fluctuation of quality for each user, and can support consistent or differentiated quality among all users to meet applications' needs. Experimental results show that compared to traditional look-ahead sliding-window approaches, our algorithm can achieve comparable visual quality and channel utilization at a much lower cost of delay, computation, and storage. %B Circuits and Systems for Video Technology, IEEE Transactions on %V 15 %P 1124 - 1137 %8 2005/09// %@ 1051-8215 %G eng %N 9 %R 10.1109/TCSVT.2005.852626 %0 Conference Paper %B IEEE International Symposium on Cluster Computing and the Grid, 2005. CCGrid 2005 %D 2005 %T Spatial indexing of distributed multidimensional datasets %A Nam,B. %A Sussman, Alan %K centralized global index algorithm %K centralized index server %K Computer science %K database indexing %K distributed databases %K distributed multidimensional dataset %K Educational institutions %K File servers %K Indexing %K Large-scale systems %K Multidimensional systems %K Network servers %K replication protocol %K replication techniques %K scalability %K Sensor systems %K spatial data structures %K spatial indexing %K two-level hierarchical index algorithm %K wide area networks %X While declustering methods for distributed multidimensional indexing of large datasets have been researched widely in the past, replication techniques for multidimensional indexes have not been investigated deeply. In general, a centralized index server may become the performance bottleneck in a wide area network rather than the data servers, since the index is likely to be accessed more often than any of the datasets in the servers. In this paper, we present two different multidimensional indexing algorithms for a distributed environment - a centralized global index and a two-level hierarchical index. Our experimental results show that the centralized scheme does not scale well for either insertion or searching the index. In order to improve the scalability of the index server, we have employed a replication protocol for both the centralized and two-level index schemes that allows some inconsistency between replicas without affecting correctness. Our experiments show that the two-level hierarchical index scheme shows better scalability for both building and searching the index than the non-replicated centralized index, but replication can make the centralized index faster than the two-level hierarchical index for searching in some cases. %B IEEE International Symposium on Cluster Computing and the Grid, 2005. CCGrid 2005 %I IEEE %V 2 %P 743- 750 Vol. 2 - 743- 750 Vol. 2 %8 2005/05/09/12 %@ 0-7803-9074-1 %G eng %R 10.1109/CCGRID.2005.1558637 %0 Conference Paper %B 13th IEEE International Symposium on High performance Distributed Computing, 2004. Proceedings %D 2004 %T Automated cluster-based Web service performance tuning %A Chung,I. -H %A Hollingsworth, Jeffrey K %K Active Harmony system %K automated performance tuning %K business %K cluster-based Web service system %K Clustering algorithms %K Computer science %K Educational institutions %K electronic commerce %K Internet %K Middleware %K performance evaluation %K scalability %K Throughput %K Transaction databases %K Web server %K Web services %K workstation clusters %X Active harmony provides a way to automate performance tuning. We apply the Active Harmony system to improve the performance of a cluster-based web service system. The performance improvement cannot easily be achieved by tuning individual components for such a system. The experimental results show that there is no single configuration for the system that performs well for all kinds of workloads. By tuning the parameters, Active Harmony helps the system adapt to different workloads and improve the performance up to 16%. For scalability, we demonstrate how to reduce the time when tuning a large system with many tunable parameters. Finally an algorithm is proposed to automatically adjust the structure of cluster-based web systems, and the system throughput is improved up to 70% using this technique. %B 13th IEEE International Symposium on High performance Distributed Computing, 2004. Proceedings %I IEEE %P 36 - 44 %8 2004/06/04/6 %@ 0-7695-2175-4 %G eng %R 10.1109/HPDC.2004.1323484 %0 Conference Paper %D 2002 %T Passive replication schemes in AQuA %A Ren,Yansong %A Rubel,P. %A Seri,M. %A Michel Cukier %A Sanders,W. H. %A Courtney,T. %K AQuA architecture %K distributed object management %K Fault tolerance %K group members %K large-scale distributed object-oriented systems %K management structure %K multidimensional quality of service %K passive replication scheme %K performance measurements %K reusable technologies %K scalability %K software fault tolerance %K software performance evaluation %K software reusability %K software solutions %X Building large-scale distributed object-oriented systems that provide multidimensional quality of service (QoS) in terms of fault tolerance, scalability, and performance is challenging. In order to meet this challenge, we need an architecture that can ensure that applications' requirements can be met while providing reusable technologies and software solutions. This paper describes techniques, based on the AQuA architecture, that enhance the applications' dependability and scalability by introducing two types of group members and a novel passive replication scheme. In addition, we describe how to make the management structure itself dependable by using the passive replication scheme. Finally, we provide performance measurements for the passive replication scheme. %P 125 - 130 %8 2002/12// %G eng %R 10.1109/PRDC.2002.1185628 %0 Journal Article %J SIGCOMM Comput. Commun. Rev. %D 2002 %T Scalable application layer multicast %A Banerjee,Suman %A Bhattacharjee, Bobby %A Kommareddy,Christopher %K application layer multicast %K hierarchy %K overlay networks %K peer-to-peer systems %K scalability %X We describe a new scalable application-layer multicast protocol, specifically designed for low-bandwidth, data streaming applications with large receiver sets. Our scheme is based upon a hierarchical clustering of the application-layer multicast peers and can support a number of different data delivery trees with desirable properties.We present extensive simulations of both our protocol and the Narada application-layer multicast protocol over Internet-like topologies. Our results show that for groups of size 32 or more, our protocol has lower link stress (by about 25%), improved or similar end-to-end latencies and similar failure recovery properties. More importantly, it is able to achieve these results by using orders of magnitude lower control traffic.Finally, we present results from our wide-area testbed in which we experimented with 32-100 member groups distributed over 8 different sites. In our experiments, average group members established and maintained low-latency paths and incurred a maximum packet loss rate of less than 1% as members randomly joined and left the multicast group. The average control overhead during our experiments was less than 1 Kbps for groups of size 100. %B SIGCOMM Comput. Commun. Rev. %V 32 %P 205 - 217 %8 2002/08// %@ 0146-4833 %G eng %U http://doi.acm.org/10.1145/964725.633045 %N 4 %R 10.1145/964725.633045 %0 Journal Article %J Parallel Computing %D 1998 %T The design and evaluation of a high-performance earth science database %A Shock,Carter T. %A Chang,Chialin %A Moon,Bongki %A Acharya,Anurag %A Davis, Larry S. %A Saltz,Joel %A Sussman, Alan %K Communication %K High-performance I/O %K load balancing %K scalability %K Scientific databases %X Earth scientists have encountered two major obstacles in their attempts to use remotely sensed imagery to analyze the earth's land cover dynamics. First, the volume of data involved is very large and second, significant preprocessing is needed before the data can be used. This is particularly so for studies that analyze global trends using data sets that cover multiple years. In this paper, we present the design of an earth science database as well as our early experiences with it. The primary design goal of this database is to facilitate efficient access to and preprocessing of large volumes of satellite data. Our initial design assumed that the main bottleneck in the system would be retrieving data from the disks. However, experimental results show that precise identification of all the data values corresponding to a query can take a significant amount of time. The problem is even more pronounced in designing the system to attempt to minimize time spent performing I/O. We therefore discuss a major redesign of the system that includes a reworking of the indexing scheme and a reorganization of the data on disks. Experimental results show that the redesigned system performs significantly better than the original system, providing interactive response times for local queries. %B Parallel Computing %V 24 %P 65 - 89 %8 1998/01// %@ 0167-8191 %G eng %U http://www.sciencedirect.com/science/article/pii/S0167819197001178 %N 1 %R 10.1016/S0167-8191(97)00117-8 %0 Journal Article %J IEEE Network %D 1998 %T The SwitchWare active network architecture %A Alexander,D. S %A Arbaugh, William A. %A Hicks, Michael W. %A Kakkar,P. %A Keromytis,A. D %A Moore,J. T %A Gunter,C. A %A Nettles,S. M %A Smith,J. M %K active extensions %K active packets %K Authentication %K Computer languages %K Computer networks %K cryptography %K cryptography-based authentication %K high-integrity base %K integrity checking %K IP networks %K LAN interconnection %K mobile programs %K network operating systems %K packet switching %K programmable network infrastructure %K programming languages %K Protocols %K Safety %K safety requirements %K scalability %K secure active router infrastructure %K Security %K security requirements %K services %K strong type checking %K Switches %K SwitchWare active network architecture %K telecommunication network routing %K Tin %K usability %K verification techniques %X Active networks must balance the flexibility of a programmable network infrastructure against the safety and security requirements inherent in sharing that infrastructure. Furthermore, this balance must be achieved while maintaining the usability of the network. The SwitchWare active network architecture is a novel approach to achieving this balance using three layers: active packets, which contain mobile programs that replace traditional packets; active extensions, which provide services on the network elements and can be dynamically loaded; and a secure active router infrastructure, which forms a high-integrity base on which the security of the other layers depends. In addition to integrity checking and cryptography-based authentication, security in our architecture depends heavily on verification techniques from programming languages, such as strong type checking %B IEEE Network %V 12 %P 29 - 36 %8 1998/06//May %@ 0890-8044 %G eng %N 3 %R 10.1109/65.690959 %0 Journal Article %J Computer %D 1995 %T The Paradyn parallel performance measurement tool %A Miller, B. P %A Callaghan, M. D %A Cargille, J. M %A Hollingsworth, Jeffrey K %A Irvin, R. B %A Karavanic, K. L %A Kunchithapadam, K. %A Newhall, T. %K Aerodynamics %K Automatic control %K automatic instrumentation control %K Debugging %K dynamic instrumentation %K flexible performance information %K high level languages %K insertion %K Instruments %K large-scale parallel program %K Large-scale systems %K measurement %K Paradyn parallel performance measurement tool %K Parallel machines %K parallel programming %K Performance Consultant %K Programming profession %K scalability %K software performance evaluation %K software tools %X Paradyn is a tool for measuring the performance of large-scale parallel programs. Our goal in designing a new performance tool was to provide detailed, flexible performance information without incurring the space (and time) overhead typically associated with trace-based tools. Paradyn achieves this goal by dynamically instrumenting the application and automatically controlling this instrumentation in search of performance problems. Dynamic instrumentation lets us defer insertion until the moment it is needed (and remove it when it is no longer needed); Paradyn's Performance Consultant decides when and where to insert instrumentation %B Computer %V 28 %P 37 - 46 %8 1995/11// %@ 0018-9162 %G eng %N 11 %R 10.1109/2.471178