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Displaying 1-50 out of 51 total
Aggregate Threshold Queries in Sensor Networks
Found in: Parallel and Distributed Processing Symposium, International
By Izchak Sharfman, Assaf Schuster, Daniel Keren
Issue Date:March 2007
pp. 107
An important class of queries over sensor networks are network-wide aggregation queries. In this work we study a class of aggregation queries which we refer to as aggregate threshold queries. The goal of an aggregate threshold query is to continuously moni...
 
Efficient On-the-Fly Data Race Detection in Multithreaded C++ Programs
Found in: Parallel and Distributed Processing Symposium, International
By Eli Poznianski, Assaf Schuster
Issue Date:April 2003
pp. 287b
<p>We present a novel testing tool, called MultiRace, which combines improved versions of Djit and Lockset — two very powerful on-the-fly algorithms for dynamic detection of apparent data races. Both extended algorithms detect races in multithreaded ...
 
ExPERT: Pareto-Efficient Task Replication on Grids and a Cloud
Found in: 2012 IEEE International Symposium on Parallel & Distributed Processing (IPDPS)
By Orna Agmon Ben-Yehuda,Assaf Schuster,Artyom Sharov,Mark Silberstein,Alexandru Iosup
Issue Date:May 2012
pp. 167-178
Many scientists perform extensive computations by executing large bags of similar tasks (BoTs) in mixtures of computational environments, such as grids and clouds. Although the reliability and cost may vary considerably across these environments, no tool e...
 
Shape Sensitive Geometric Monitoring
Found in: IEEE Transactions on Knowledge and Data Engineering
By Daniel Keren,Izchak Sharfman,Assaf Schuster,Avishay Livne
Issue Date:August 2012
pp. 1520-1535
An important problem in distributed, dynamic databases is to continuously monitor the value of a function defined on the nodes, and check that it satisfies some threshold constraint. We introduce a monitoring method, based on a geometric interpretation of ...
 
GridBot: execution of bags of tasks in multiple grids
Found in: SC Conference
By Mark Silberstein, Artyom Sharov, Dan Geiger, Assaf Schuster
Issue Date:November 2009
pp. 1-12
We present a holistic approach for efficient execution of bags-of-tasks (BOTs) on multiple grids, clusters, and volunteer computing grids virtualized as a single computing platform. The challenge is twofold: to assemble this compound environment and to emp...
 
Digging Deep into the Data Mine with DataMiningGrid
Found in: IEEE Internet Computing
By Vlado Stankovski, Martin Swain, Valentin Kravtsov, Thomas Niessen, Dennis Wegener, Matthias Röhm, Jernej Trnkoczy, Michael May, Jürgen Franke, Assaf Schuster, Werner Dubitzky
Issue Date:November 2008
pp. 69-76
The growing computerization in modern knowledge and technology sectors is generating huge volumes of electronically stored data. Data mining technology is often employed to make sense of these data. However, as modern data mining applications increase in c...
 
MC2: Multiple Clients on a Multilevel Cache
Found in: Distributed Computing Systems, International Conference on
By Gala Yadgar, Michael Factor, Kai Li, Assaf Schuster
Issue Date:June 2008
pp. 722-730
In today's networked storage environment, it is common to have a hierarchy of caches where the lower levels of the hierarchy are accessed by multiple clients. This sharing can have both positive or negative effects. While data fetched by one client can be ...
 
Code Compilation for an Explicitly Parallel Register-Sharing Architecture
Found in: Parallel Processing, International Conference on
By Alex Gontmakher, Avi Mendelson, Assaf Schuster, Gregory Shklover
Issue Date:September 2007
pp. 58
Code generation for a multithreaded register sharing architecture is inherently complex and involves some issues absent in conventional code compilation. To approach the problem, we define a consistency contract between the program and the hardware and req...
 
In-Kernel Integration of Operating System and Infiniband Functions for High Performance Computing Clusters: A DSM Example
Found in: IEEE Transactions on Parallel and Distributed Systems
By Liran Liss, Yitzhak Birk, Assaf Schuster
Issue Date:September 2005
pp. 830-840
<p><b>Abstract</b>—The Infiniband (IB) System Area Network (SAN) enables applications to access hardware directly from user level, reducing the overhead of user-kernel crossings during data transfer. However, distributed applications that...
 
Hierarchical Decision Tree Induction in Distributed Genomic Databases
Found in: IEEE Transactions on Knowledge and Data Engineering
By Amir Bar-Or, Daniel Keren, Assaf Schuster, Ran Wolff
Issue Date:August 2005
pp. 1138-1151
Classification based on decision trees is one of the important problems in data mining and has applications in many fields. In recent years, database systems have become highly distributed, and distributed system paradigms, such as federated and peer-to-pe...
 
Privacy-Preserving Data Mining on Data Grids in the Presence of Malicious Participants
Found in: High-Performance Distributed Computing, International Symposium on
By Bobi Gilburd, Assaf Schuster, Ran Wolff
Issue Date:June 2004
pp. 225-234
Data privacy is a major threat to the widespread deployment of data grids in domains such as health care and finance. We propose a novel technique for obtaining knowledge - by way of a data mining model - from a data grid, while ensuring that the privacy i...
 
A Distributed Runtime for Java: Yesterday and Today
Found in: Parallel and Distributed Processing Symposium, International
By Michael Factor, Assaf Schuster, Konstantin Shagin
Issue Date:April 2004
pp. 159a
Since the introduction of the Java language less then a decade ago, there have been several attempts to create a runtime system for distributed execution of multi-threaded Java applications. The goal of these attempts was to gain increased computational po...
 
Multithreaded Home-Based Lazy Release Consistency over VIA
Found in: Parallel and Distributed Processing Symposium, International
By Vadim Iosevich, Assaf Schuster
Issue Date:April 2004
pp. 59b
A Distributed Shared Memory (DSM) system is a software or hardware mechanism that provides a distributed application with a shared virtual address space. The efficiency of a DSM system relies mainly on a memory coherency protocol and an efficient communica...
 
JavaSplit: A Runtime for Execution of Monolithic Java Programs on Heterogeneous Collections of Commodity Workstations
Found in: Cluster Computing, IEEE International Conference on
By Michael Factor, Assaf Schuster, Konstantin Shagin
Issue Date:December 2003
pp. 110
This paper presents JavaSplit, a portable runtime for distributed execution of multithreaded Java programs. Java-Split transparently distributes threads and objects of an application among the participating nodes. Thus, it gains augmented computational pow...
 
A High-Performance Distributed Algorithm for Mining Association Rules
Found in: Data Mining, IEEE International Conference on
By Assaf Schuster, Ran Wolff, Dan Trock
Issue Date:November 2003
pp. 291
We present a new distributed association rule mining (D-ARM) algorithm that demonstrates superlinear speedup with the number of computing nodes. The algorithm is the first D-ARM algorithm to perform a single scan over the database. As such, its performance...
 
Efficient Exploitation of Kernel Access to Infiniband: A Software DSM Example
Found in: High-Performance Interconnects, Symposium on
By Liran Liss, Yitzhak Birk, Assaf Schuster
Issue Date:August 2003
pp. 130
The Infiniband (IB) System Area Network (SAN) enables applications to access hardware directly from user level, reducing the overhead of user-kernel crossings during data transfer. However, distributed applications that exhibit close coupling between netwo...
 
Transparent Adaptation of Sharing Granularity in MultiView-Based DSM Systems
Found in: Parallel and Distributed Processing Symposium, International
By Nitzan Niv, Assaf Schuster
Issue Date:April 2001
pp. 10038a
In this paper we propose a mechanism that provides DSM systems with a flexible sharing granularity. The size of the shared memory units is dynamically determined by the system during runtime. This size can range from that of a single variable up to the siz...
 
Hot-Potato Algorithms for Permutation Routing
Found in: IEEE Transactions on Parallel and Distributed Systems
By Ilan Newman, Assaf Schuster
Issue Date:November 1995
pp. 1168-1176
<p><it>Abstract</it>—We develop a methodology for the design of hot-potato algorithms for routing permutations. The basic idea is to convert existing store-and-forward routing algorithms to hot-potato algorithms. Using it, we obtain the f...
 
Latent fault detection in large scale services
Found in: 2012 42nd Annual IEEE/IFIP International Conference on Dependable Systems and Networks (DSN)
By Moshe Gabel,Assaf Schuster,Ran-Gilad Bachrach,Nikolaj Bjorner
Issue Date:June 2012
pp. 1-12
Unexpected machine failures, with their resulting service outages and data loss, pose challenges to datacenter management. Existing failure detection techniques rely on domain knowledge, precious (often unavailable) training data, textual console logs, or ...
   
Running Parallel Applications with Topology-Aware Grid Middleware
Found in: e-Science and Grid Computing, International Conference on
By Pavel Bar, Camille Coti, Derek Groen, Thomas Herault, Valentin Kravtsov, Assaf Schuster, Martin Swain
Issue Date:December 2009
pp. 292-299
The concept of topology-aware grid applications is derived from parallelized computational models of complex systems that are executed on heterogeneous resources, either because they require specialized hardware for certain calculations, or because their p...
 
Association Rule Mining in Peer-to-Peer Systems
Found in: Data Mining, IEEE International Conference on
By Ran Wolff, Assaf Schuster
Issue Date:November 2003
pp. 363
We extend the problem of association rule mining - a key data mining problem - to systems in which the database is partitioned among a very large number of computers that are dispersed over a wide area. Such computing systems include GRID computing platfor...
 
Dynamic Adaptation of Sharing Granularity in DSM Systems
Found in: Parallel Processing, International Conference on
By Ayal Itzkovitz, Nitzan Niv, Assaf Schuster
Issue Date:September 1999
pp. 220
The tradeoff between false sharing elimination and aggregation in Distributed Shared Memory (DSM) systems has a major effect on their performance. Some studies in this area show that fine grain access is advantageous, while others advocate the use of large...
 
Cooperative caching with return on investment
Found in: 2013 IEEE 29th Symposium on Mass Storage Systems and Technologies (MSST)
By Gala Yadgar,Michael Factor,Assaf Schuster
Issue Date:May 2013
pp. 1-13
Large scale consolidation of distributed systems introduces data sharing between consumers which are not centrally managed, but may be physically adjacent. For example, shared global data sets can be jointly used by different services of the same organizat...
   
Single Step Undirected Reconfigurable Networks
Found in: High-Performance Computing, International Conference on
By Yosi Ben-Asher, Assaf Schuster
Issue Date:December 1997
pp. 284
The reconfigurable mesh (RN-MESH) can solve a large class of problems in constant time, including problems that require logarithmic time by other, even shared memory, models such as the pram with a similar number of processors [3]. In this work we show tha...
 
Ginseng: market-driven memory allocation
Found in: Proceedings of the 10th ACM SIGPLAN/SIGOPS international conference on Virtual execution environments (VEE '14)
By Ahuva Mu'alem, Assaf Schuster, Eyal Posener, Muli Ben-Yehuda, Orna Agmon Ben-Yehuda
Issue Date:March 2014
pp. 41-52
Physical memory is the scarcest resource in today's cloud computing platforms. Cloud providers would like to maximize their clients' satisfaction by renting precious physical memory to those clients who value it the most. But real-world cloud clients are s...
     
VSwapper: a memory swapper for virtualized environments
Found in: Proceedings of the 19th international conference on Architectural support for programming languages and operating systems (ASPLOS '14)
By Assaf Schuster, Dan Tsafrir, Nadav Amit
Issue Date:March 2014
pp. 349-366
The number of guest virtual machines that can be consolidated on one physical host is typically limited by the memory size, motivating memory overcommitment. Guests are given a choice to either install a "balloon" driver to coordinate the overcommitment ac...
     
Deconstructing Amazon EC2 Spot Instance Pricing
Found in: ACM Transactions on Economics and Computation
By Assaf Schuster, Dan Tsafrir, Muli Ben-Yehuda, Orna Agmon Ben-Yehuda
Issue Date:September 2013
pp. 1-20
Cloud providers possessing large quantities of spare capacity must either incentivize clients to purchase it or suffer losses. Amazon is the first cloud provider to address this challenge, by allowing clients to bid on spare capacity and by granting resour...
     
Scheduling processing of real-time data streams on heterogeneous multi-GPU systems
Found in: Proceedings of the 5th Annual International Systems and Storage Conference (SYSTOR '12)
By Assaf Schuster, Avi Mendelson, Mark Silberstein, Uri Verner
Issue Date:June 2012
pp. 1-12
Processing vast numbers of data streams is a common problem in modern computer systems and is known as the "online big data problem." Adding hard real-time constraints to the processing makes the scheduling problem a very challenging task that this paper a...
     
ELI: bare-metal performance for I/O virtualization
Found in: Proceedings of the seventeenth international conference on Architectural Support for Programming Languages and Operating Systems (ASPLOS '12)
By Abel Gordon, Alex Landau, Assaf Schuster, Dan Tsafrir, Muli Ben-Yehuda, Nadav Amit, Nadav Har'El
Issue Date:March 2012
pp. 411-422
Direct device assignment enhances the performance of guest virtual machines by allowing them to communicate with I/O devices without host involvement. But even with device assignment, guests are still unable to approach bare-metal performance, because the ...
     
Processing data streams with hard real-time constraints on heterogeneous systems
Found in: Proceedings of the international conference on Supercomputing (ICS '11)
By Assaf Schuster, Mark Silberstein, Uri Verner
Issue Date:May 2011
pp. 120-129
Data stream processing applications such as stock exchange data analysis, VoIP streaming, and sensor data processing pose two conflicting challenges: short per-stream latency -- to satisfy the milliseconds-long, hard real-time constraints of each stream, a...
     
Management of Multilevel, Multiclient Cache Hierarchies with Application Hints
Found in: ACM Transactions on Computer Systems (TOCS)
By Assaf Schuster, Gala Yadgar, Gala Yadgar, Kai Li, Kai Li, Michael Factor, Michael Factor
Issue Date:May 2011
pp. 1-51
Multilevel caching, common in many storage configurations, introduces new challenges to traditional cache management: data must be kept in the appropriate cache and replication avoided across the various cache levels. Additional challenges are introduced w...
     
Data mining with differential privacy
Found in: Proceedings of the 16th ACM SIGKDD international conference on Knowledge discovery and data mining (KDD '10)
By Arik Friedman, Assaf Schuster
Issue Date:July 2010
pp. 493-502
We consider the problem of data mining with formal privacy guarantees, given a data access interface based on the differential privacy framework. Differential privacy requires that computations be insensitive to changes in any particular individual's recor...
     
GridBot: execution of bags of tasks in multiple grids
Found in: Proceedings of the Conference on High Performance Computing Networking, Storage and Analysis (SC '09)
By Artyom Sharov, Assaf Schuster, Dan Geiger, Mark Silberstein
Issue Date:November 2009
pp. 1-12
We present a holistic approach for efficient execution of bags-of-tasks (BOTs) on multiple grids, clusters, and volunteer computing grids virtualized as a single computing platform. The challenge is twofold: to assemble this compound environment and to emp...
     
Optimistic concurrency for clusters via speculative locking
Found in: Proceedings of SYSTOR 2009: The Israeli Experimental Systems Conference (SYSTOR '09)
By Assaf Schuster, Konstantin Shagin, Michael Factor, Tal Zamir
Issue Date:May 2009
pp. 1-42
Transactional memory and speculative locking are optimistic concurrency control mechanisms, whose goal is to enable highly concurrent execution while reducing the programming effort. The same basic idea lies in the heart of both methods: optimistically exe...
     
Shape sensitive geometric monitoring
Found in: Proceedings of the twenty-seventh ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (PODS '08)
By Assaf Schuster, Daniel Keren, Izchak Sharfman
Issue Date:June 2008
pp. 1-1
A fundamental problem in distributed computation is the distributed evaluation of functions. The goal is to determine the value of a function over a set of distributed inputs, in a communication efficient manner. Specifically, we assume that each node hold...
     
Efficient computation of sum-products on GPUs through software-managed cache
Found in: Proceedings of the 22nd annual international conference on Supercomputing (ICS '08)
By Anjul Patney, Assaf Schuster, Dan Geiger, John D. Owens, Mark Silberstein
Issue Date:June 2008
pp. 3-3
We present a technique for designing memory-bound algorithms with high data reuse on Graphics Processing Units (GPUs) equipped with close-to-ALU software-managed memory. The approach is based on the efficient use of this memory through the implementation o...
     
A geometric approach to monitoring threshold functions over distributed data streams
Found in: ACM Transactions on Database Systems (TODS)
By Assaf Schuster, Daniel Keren, Izchak Sharfman
Issue Date:November 2007
pp. 23-es
Monitoring data streams in a distributed system is the focus of much research in recent years. Most of the proposed schemes, however, deal with monitoring simple aggregated values, such as the frequency of appearance of items in the streams. More involved ...
     
Using fine grain multithreading for energy efficient computing
Found in: Proceedings of the 12th ACM SIGPLAN symposium on Principles and practice of parallel programming (PPoPP '07)
By Alex Gontmakher, Assaf Schuster, Avi Mendelson
Issue Date:March 2007
pp. 259-269
We investigate extremely fine-grain multithreading as a means for improving energy efficiency of single-task program execution.Our work is based on low-overhead threads executing an explicitly parallel program in a register-sharing context. The thread-base...
     
Mining for misconfigured machines in grid systems
Found in: Proceedings of the 12th ACM SIGKDD international conference on Knowledge discovery and data mining (KDD '06)
By Arie Leizarowitz, Assaf Schuster, Noam Palatin, Ran Wolff
Issue Date:August 2006
pp. 687-692
Grid systems are proving increasingly useful for managing the batch computing jobs of organizations. One well-known example is Intel, whose internally developed NetBatch system manages tens of thousands of machines. The size, heterogeneity, and complexity ...
     
Veracity radius: capturing the locality of distributed computations
Found in: Proceedings of the twenty-fifth annual ACM symposium on Principles of distributed computing (PODC '06)
By Assaf Schuster, Idit Keidar, Liran Liss, Ran Wolff, Yitzhak Birk
Issue Date:July 2006
pp. 102-111
This paper focuses on local computations of distributed aggregation problems on fixed graphs. We define a new metric on problem instances, Veracity Radius (VR), which captures the inherent possibility to compute them locally. We prove that VR yields a tigh...
     
A geometric approach to monitoring threshold functions over distributed data streams
Found in: Proceedings of the 2006 ACM SIGMOD international conference on Management of data (SIGMOD '06)
By Assaf Schuster, Daniel Keren, Izchak Sharfman
Issue Date:June 2006
pp. 301-312
Monitoring data streams in a distributed system is the focus of much research in recent years. Most of the proposed schemes, however, deal with monitoring simple aggregated values, such as the frequency of appearance of items in the streams. More involved ...
     
Scaling model checking of dataraces using dynamic information
Found in: Proceedings of the tenth ACM SIGPLAN symposium on Principles and practice of parallel programming (PPoPP '05)
By Assaf Schuster, Mooly Sagiv, Ohad Shacham
Issue Date:June 2005
pp. 107-118
Dataraces in multithreaded programs often indicate severe bugs and can cause unexpected behaviors when different thread interleavings are executed. Because dataraces are a cause for concern, many works have dealt with the problem of detecting them. Works b...
     
Instrumentation of standard libraries in object-oriented languages: the twin class hierarchy approach
Found in: Proceedings of the 19th annual ACM SIGPLAN Conference on Object-oriented programming, systems, languages, and applications (OOPSLA '04)
By Assaf Schuster, Konstantin Shagin, Michael Factor
Issue Date:October 2004
pp. 328-329
Code instrumentation is widely used for a range of purposes that include profiling, debugging, visualization, logging, and distributed computing. Due to their special status within the language infrastructure, the <i>standard class libraries</i>, a...
     
k-TTP: a new privacy model for large-scale distributed environments
Found in: Proceedings of the 2004 ACM SIGKDD international conference on Knowledge discovery and data mining (KDD '04)
By Assaf Schuster, Bobi Gilburd, Ran Wolff
Issue Date:August 2004
pp. 563-568
Secure multiparty computation allows parties to jointly compute a function of their private inputs without revealing anything but the output. Theoretical results [2] provide a general construction of such protocols for any function. Protocols obtained in t...
     
A comparison of sequential consistency with home-based lazy release consistency for software distributed shared memory
Found in: Proceedings of the 18th annual international conference on Supercomputing (ICS '04)
By Assaf Schuster, Vadim Iosevich
Issue Date:June 2004
pp. 306-315
A Distributed Shared Memory (DSM) system provides a distributed application with a shared virtual address space. Choosing a memory consistency model is one of the main decisions in designing a DSM system. While Sequential Consistency provides a simple and ...
     
Efficient on-the-fly data race detection in multithreaded C++ programs
Found in: Proceedings of the ninth ACM SIGPLAN symposium on Principles and practice of parallel programming (PPoPP '03)
By Assaf Schuster, Eli Pozniansky
Issue Date:June 2003
pp. 179-190
Data race detection is highly essential for debugging multithreaded programs and assuring their correctness. Nevertheless, there is no single universal technique capable of handling the task efficiently, since the data race detection problem is computation...
     
Execution of monolithic Java programs on large non-dedicated collections of commodity workstations
Found in: Proceedings of the 2002 joint ACM-ISCOPE conference on Java Grande (JGI '02)
By Assaf Schuster, Konstantin Shagin, Michael Factor
Issue Date:November 2002
pp. 227-227
Today's typical computational environment consists of a large numbers of commodity workstations interconnected by high bandwidth networks. However, only a small portion of workstation's capacity is utilized since a large share of workstations may be idle a...
     
Communication-efficient distributed mining of association rules
Found in: Proceedings of the 2001 ACM SIGMOD international conference on Management of data (SIGMOD '01)
By Assaf Schuster, Ran Wolff
Issue Date:May 2001
pp. 256-266
Mining for associations between items in large transactional databases is a central problem in the field of knowledge discovery. When the database is partitioned among several share-nothing machines, the problem can be addressed using distributed data mini...
     
Parallel progressive rendering of animation sequences at interactive rates on distributed-memory machines
Found in: Proceedings of the IEEE symposium on Parallel rendering (PRS '97)
By Amit Reisman, Assaf Schuster, Craig Gotsman
Issue Date:October 1997
pp. 39-47
ARMI is a communication library that provides a framework for expressing fine-grain parallelism and mapping it to a particular machine using shared-memory and message passing library calls. The library is an advanced implementation of the RMI protocol and ...
     
Potential function analysis of greedy hot-potato routing
Found in: Proceedings of the thirteenth annual ACM symposium on Principles of distributed computing (PODC '94)
By Amir Ben-Dor, Assaf Schuster, Shai Halevi
Issue Date:August 1994
pp. 225-234
In [4] a randomized algorithm for mutual exclusion with bounded waiting, employing a logarithmic sized shared variable, was given. Saias and Lynch [5] pointed out that the adversary scheduler postulated in the above paper can observe the behavior of proces...
     
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