15841052
The second trans-Pacific Grid Datafarm testbed and experiments for SC2003
The Grid Datafarm architecture is designed for global petascale data-intensive computing. It provides a global parallel file system (Gfarm file system) with online petascale storage, scalable I/O bandwidth, and scalable parallel processing by federating thousands of local file systems in a grid of clusters securely using Grid security infrastructure. One of features is that it manages file replicas in filesystem metadata for fault tolerance and load balancing. Here, we present an overview of our planned experiment performed as the SC2003 Bandwidth Challenge at the Supercomputing 2003 site in Phoenix, Arizona, USA. In the experiment, five clusters in Japan and three clusters in US comprise a Gfarm file system, on which world-wide largescale data analysis is performed. In the Gfarm file system, a file is dispersed in several cluster nodes, each of which is replicated independently and in parallel by multiple third-party transfers between multiple cluster nodes. For the Challenge, terabyte-scale experimental data is replicated between US and Japan via APAN/TransPAC and SuperSINET (about 10,000 km or 6,000 miles). At the workshop we present the full detail of the experiment.
280911
Multiple instruction streams in a highly pipelined processor
In a highly pipelined processor, instruction dependencies involving both and control information often limit its potential performance. A cyclic pipeline machine allows multiple instruction streams to share these pipeline stages in time to remove the data and control dependencies. These multiple instruction streams exploit more parallelism in parallel programs. It provides an alternative architectural solution for new technologies such as GaAs and Josephson logic device, which prefer a highly pipelined architecture. The authors define the basic model of a cyclic pipeline machine, and examine the performance improvement of various configurations of cyclic pipeline machines compared to the same degree of pipelining of a conventional pipelined processor. The simulation results indicate that pipelining in the individual instruction streams increases the performance to maximize the utilization of resources in a highly pipelined processor.<<ETX>>
31888240
Performance Improvement by Data Management Layer in a Grid RPC System
A grid RPC system provides a useful and intuitive programming interface for master-worker type applications in a grid environment. In many grid applications, such as parameter search programs, both master and workers are often required to have a large amount of common data. Since in the RPC model the data must be transferred from the master directly to each worker, the master is sometimes a bottleneck, resulting in poor performance. In order to improve the performance in such cases, we propose a model to decouple the data transfer by a data management layer from the RPC programming. We have designed and implemented a prototype data transfer layer called OmniStorage to OmniRPC, which is a grid RPC system for parallel programming in a grid environment. This allows efficient data transmission of a large amount of data by placing intermediate relay servers, taking the network topology into account, to route the communication and cache the common data in the server. We have evaluated the performance of the proposed system by using synthetic workloads and a real grid application. The results show that OmniStorage can improve the performance of OmniRPC applications compared to the case of using only OmniRPC.
12665758
Direct Execution of Linux Binary on Windows for Grid RPC Workers
Local area or campus-type networks consist of PCs using different operating systems such as Windows and Linux. These PCs are expected to have enormous potential computing power for grid computing. The majority of PCs in this type of environment run on Windows, while grid applications and middleware are often developed on Linux. The challenge is to absorb the heterogeneity of operating systems. Grid RPC is a promising programming model for the development of grid applications. We have designed and implemented an agent called BEE, which enables direct execution of Linux binary programs on Windows for a grid RPC worker. We have integrated the BEE agent into an OmniRPC system in order to make use of Windows PCs as computing resources in a hybrid grid environment combining Windows PCs into grid computing resources. The BEE agent allows Linux binaries of the program of the OmniRPC worker to be exported and run under Windows without any modification of its Linux binaries. The results of our experiments show that the performance of a worker program using BEE is almost the same as that of Windows native binary and Cygwin and is better that that of using VMware. We have demonstrated a hybrid grid environment combining Window PCs in a conventional grid of Linux nodes.
195869612
The EM-X parallel computer: architecture and basic performance
Latency tolerance is essential in achieving high performance on parallel computers for remote function calls and fine-grained remote memory accesses. EM-X supports interprocessor communication on an execution pipeline with small and simple packets. It can create a packet in one cycle, and receive a packet from the network in the on-chip buffer without interruption. EM-X invokes threads on packet arrival, minimizing the overhead of thread switching. It can tolerate communication latency by using efficient multi-threading and optimizing packet flow of fine grain communication. EM-X also supports the synchronization of two operands, direct remote memory read/write operations and flexible packet scheduling with priority. The paper describes distinctive features of the EM-X architecture and reports the performance of small synthetic programs and larger more realistic programs.
206034930
Performance Evaluation of a Workstation Cluster, TMC CM-5, and Intel Paragon/XP Using a Parallel Homology Analysis Program
Abstract In the homology analysis, required memory size and computing time proportionally increase with the square of the number of amino acids in protein. In order to expand the limit of size and to carry out analysis effectively, we parallelized for homology analysis program adopting the wavefront method with tiling. The performance of a workstation cluster, CM5, and Paragon was compared by using our program. For performance evaluation of these machines, we have made a model of our parallel homology analysis computation. Using the model, we can understand the characteristics of these machines with respect to our program. Execution time estimated by the execution model is in good agreement with the observation. The averaged error of the estimation to the observation on a workstation cluster, CM5, and Paragon are 0.1%, 5%, and 2%. Almost linear speed-up has been observed from 1PU to 20PUs on them. The ratio of the performance of Paragon, CM5, and the workstation cluster is 1:0.38:0.22. This ratio is constant to the variety of the size of problem and the number of processors.
8686702
Theory of Judgments and Derivations
We propose a computational and logical framework NF (Natural Framework) which is suitable for presenting mathematics formally. Our framework is an extendable framework since it is open-ended both computationally and logically in the sense of Martin-Lof's theory or types. NF is developed in three steps. Firstly, we introduce a theory of expressions and schemata which is used to provide a universe for representing mathematical objects, in particular, judgments and derivations as well as other usual mathematical objects. Secondly, we develop a theory of judgments within the syntactic universe of expressions. Finally, we introduce the notions of derivation and derivation game and will show that we can develop mathematics as derivation games by regarding mathematics as an open-ended process of defining new concepts and deriving new judgments. Our theory is inspired by Martin-Lof's theory of expressions and Edinburgh LF, but conceptually much simpler. Our theory is also influenced by Gentzen's natural deduction systems.
27411446
A Purely Functional Language with Encapsulated Assignment
We introduce a new functional programming language with assignment. The language, which we call Λ, is a conservative extension of the λβ-calculus, and as such it it a higher order functional language in which we can manipulate functions as first class objects. Λ has a lazy evaluation semantics and Λ programs can be evaluated in parallel. Λ also supports imperative programming in terms of assignments. All the assingments in Λ are encapsulated within suitable scope of the let constructs. The language is therefore side-effect free and referentially transparent. We show by an example that we can smoothly reason about Λ programs.
46610662
CAL: A Computer Assisted Learning System for Computation and Logic
In this paper, we describe a computer system CAL which assists students' understanding of a lecture course in logic and computation. We introduce a new foundational theory of expressions, which is inspired by the theory of expressions due to Martin-Lof [6], and use the expressions determined by the theory to implement various syntactic objects in CAL. We also introduce the concept of derivation game, and show that various logical and computational systems given in the lecture course can be defined uniformly by derivation games.
32331384
Intuitionistic and Classical Natural Deduction Systems with the Catch and the Throw Rules
1796136
Strong normalizability of the non-deterministic catch/throw calculi
The catch/throw mechanism in Common Lisp provides a simple control mechanism for non-local exits. We study typed calculi by Nakano and Sato which formalize the catch/throw mechanism. These calculi correspond to classical logic through the Curry-Howard isomorphism, and one of their characteristic points is that they have non-deterministic reduction rules. These calculi can represent various computational meaning of classical proofs. This paper is mainly concerned with the strong normalizability of these calculi. Namely, we prove the strong normalizability of these calculi, which was an open problem. We first formulate a non-deterministic variant of Parigot's λμ-calculus, and show it is strongly normalizing. We then translate the catch/throw calculi to this variant. Since the translation preserves typing and reduction, we obtain the strong normalization of the catch/throw calculi. We also briefly consider second-order extension of the catch/throw calculi. Copyright 2002 Elsevier Science B.V