Java Grande 2000 Special Issue of Concurrency:Practice and Experience

Original Conference URL http://www.extreme.indiana.edu/java00

• C477: CoG Kits: A Bridge between Commodity Distributed Computing and High-Performance Grids
• Abstract: Emerging national-scale "Computational Grid" infrastructures are deploying advanced services beyond those taken for granted in today’s Internet: for example, authentication, remote access to computers, resource management, and directory services. The availability of these services represents both an opportunity and a challenge for the application developer: an opportunity because they enable access to remote resources in new ways, a challenge because these services may not be compatible with the commodity distributed computing technologies used for application development. The Commodity Grid project is working to overcome this difficulty by creating what we call Commodity Grid Toolkits (CoG Kits) that define mappings and interfaces between Grid and particular commodity frameworks. In this paper, we explain why CoG Kits are important, describe the design and implementation of a Java CoG Kit, and use examples to illustrate how CoG Kits can enable new approaches to application development based on the integrated use of commodity and Grid technologies.
• Gregor von Laszewski, Ian Foster, Jarek Gawor
• Argonne National Laboratory, Argonne, IL 60439, U.S.A.
• email gregor@mcs.anl.gov
• Original PDF: C477gregor/cog-cpe.pdf
• C478: Strategies for the efficient exploitation of loop-level parallelism in Java
• Abstract:This paper analyzes the overheads incurred in the exploitation of loop-level parallelism using Java Threads and pro poses some code transformations that minimize them. Avoiding the intensive use of Java Threads and reducing the number of classes used to specify the parallelism in the application results in promising performance gains that may en courage the use of Java for exploiting loop-level parallelism. On average, the execution time for our synthetic benchmarks is reduced by 50% from the simplest transformation when 8 threads are used. The paper explores some possible enhancements to the Java threading API oriented towards improving the application-runtime interaction.
• Jose Oliver, Eduard Ayguad´e, Nacho Navarro, Jordi Guitart and Jordi Torres
• Computer Architecture Department, Technical University Of Catalonia, C/ Jordi Girona 1-3, Campus Nord, 08034 Barcelona, Spain
• email{joseo,eduard,nacho,jguitart,torres}@ac.upc.es
• Original PDF: C478segura/Article.pdf
• C479: Parallel Application Experience with Replicated Method Invocation
• Abstract:Parallel Application Experience withWe describe and evaluate a new approach to object replication in Java, aimed at improving the performance of parallel programs. Our programming model allows the programmer to define groups of objects that can be replicated and updated as a whole, using totally-ordered broadcast to send update methods to all machines containing a copy. The model has been implemented in the Manta high-performance Java system. We evaluate system performance both with micro benchmarks and with a set of five parallel applications. For the applications, we also evaluate ease of programming, compared to RMI implementations. We present performance results for a Myrinet-based workstation cluster as well as for a wide-area distributed system consisting of four such clusters. The micro benchmarks show that updating a replicated object on 64 machines only takes about three times the RMI latency in Manta. Applications using Manta’s object replication mechanism perform at least as fast as manually optimized versions based on RMI, while keeping the application code as simple as with naive versions that use shared objects without taking locality into account. Using a replication mechanism in Manta’s runtime system enables several unmodified applications to run efficiently even on the wide-area system.Replicated Method Invocation
• Jason Maassen, Thilo Kielmann, Henri E. Bal
• Division of Mathematics and Computer Science, Vrije Universiteit, Amsterdam, The Netherlands
• emailjason@cs.vu.nl, kielmann@cs.vu.nl, bal@cs.vu.nl
• Original PDF: C479maassen/cpe00-letter.pdf
• C480: High-Performance File I/O in Java: Existing Approaches and Bulk I/O Extensions
• Abstract:There is a growing interest in using Java as the language for developing high-performance computing applications. To be successful in the high-performance computing domain, however, Java must not only be able to provide high computational performance, but also high-performance I/O. In this paper, we first examine several approaches that attempt to provide high-performance I/O in Java|many of which are not obvious at first glance|and evaluate their performance on two parallel machines, the IBM SP and the SGI Origin2000. We then propose extensions to the Java I/O library that address the deficiencies in the Java I/O API and improve performance dramatically. The extensions add bulk (array) I/O operations to Java, thereby removing much of the overhead currently associated with array I/O in Java. We have implemented the extensions in two ways: in a standard JVM using the Java Native Interface (JNI) and in a high-performance parallel dialect of Java called Titanium. We describe the two implementations and present performance results that demonstrate the benefits of the proposed extensions.
• Dan Bonachea, Phillip Dickens, Rajeev Thakur
• UCB, IIT and Argonne National Laboratory
• emailbonachea@cs.berkeley.edu, pmd@work.csam.iit.edu, thakur@mcs.anl.gov
• Original PDF: C480thakur/thakur.pdf
• C481: DISCOVER: An Environment for Web-based Interaction and Steering of High-Performance Scientific Applications
• Abstract:This paper presents the design, implementation, and deployment of the DISCOVER (Distributed Interactive Steering and Collaborative Visualization EnviRonment) web-based computational collaboratory. The primary goal of this collaboratory is to bring large distributed simulations to the scientists’/engineers’ desktop by providing collaborative web-based portals for interaction and control. DISCOVER provides a 3-tier architecture composed of detachable thin-clients at the front-end, a network of web servers in the middle, and a control network of sensors, actuators, interaction agents superimposed on the application at the back-end. The interaction servers build on servlet technology and enable clients to connect to, and collaboratively interact with registered applications using a conventional browser. The application control network enables sensors and actuators to be encapsulated within, and directly deployed with the computational objects. Interaction agents resident at each computational node register the interaction objects and export their interaction interfaces. The application interaction gateway manages the overall interaction through the control network of interaction agents and objects. It uses the Java Native Interface to create Java proxy objects that mirror the computational objects and allow them to be directly accessed by the interaction web-server. Security and authentication services are provided using customizable access control lists built on the SSL-based secure server.
• Vijay Mann, Vincent Matossian, Rajeev Muralidhar and Manish Parashar
• Department of Electrical and Computer Engineering and CAIP Center, Rutgers University, 94 Brett Road, Piscataway, NJ 08854.
• email{vijay,vincentm,rajeevdm,parashar}@caip.rutgers.edu
• Original PDF: C481parashar/JavaGrandeJournal.pdf
• C482: Interceptors for Java Remote Method Invocation
• Abstract:Interceptors are software mechanisms that are inserted into an application at runtime, and can subsequently provide hooks to introduce new services to the application in a transparent manner. We have developed three distinct interceptors that are targeted at Java Remote Method Invocation. Our interceptors are novel in that they are developed independent of the application, and are easy to deploy, requiring little or no modification to the application. We exploit interception in the Aroma System that we have developed, to install mechanisms for the consistent replication of Java objects at runtime. These replication mechanisms can be exploited to provide fault tolerance and high availability to a distributed application, in a transparent manner.
• Nitya Narasimhan, L. E. Moser and P. M. Melliar-Smith
• Department of Electrical and Computer Engineering University of California, Santa Barbara, CA 93106
• emailnitya@alpha.ece.ucsb.edu
• Original PDF: C482narasinmhan/CPE2000.pdf
• C483: HBench:Java: An Application-Specific Benchmarking Framework for Java Virtual Machines
• Abstract:Java applications represent a broad class of programs, ranging from programs running on embedded products to high-performance server applications. Standard Java benchmarks ignore this fact and assume a fixed workload. When an actual application’s behavior differs from that included in a standard benchmark, the benchmark results are useless, if not misleading. In this paper, we present HBench:Java, an application-specific benchmarking framework, based on the concept that a system's performance must be measured in the context of the application of interest. HBench:Java employs a methodology that uses vectors to characterize the application and the underlying JVM and carefully combines the two vectors to form a single metric that reflects a specific application’s performance on a particular JVM such that the performance of multiple JVMs can be realistically compared. Our performance results demonstrate HBench:Java’s superiority over traditional benchmarking approaches in predicting real application performance and its ability to pinpoint performance problems.
• Xiaolan Zhang, Margo Seltzer
• Division of Engineering and Applied Sciences Harvard University 33 Oxford Street Cambridge, MA 02138, USA 617-495-3311, 617-496-5663
• email{cxzhang, margo}@eecs.harvard.edu
• Original PDF: C483zhang/submit.pdf
• C484: An OpenMP-like Interface for Parallel Programming in Java
• Abstract:This paper describes the definition and implementation of an OpenMP-like set of directives and library routines for shared memory parallel programming in Java. A specification of the directives and routines is proposed and discussed. A prototype implementation, consisting of a compiler and a runtime library, both written entirely in Java, is presented, which implements a significant subset of the proposed specification.
• M. E. Kambites, J. M. Bull
• Department of Mathematics, University of York, Heslington, York YO10 5DD, England, U.K. , and Edinburgh Parallel Computing Centre, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, Scotland, U.K.
• emailmek100@york.ac.uk, m.bull@epcc.ed.ac.uk
• Original PDF: C484bull/ccpe.pdf
• C485: Using JavaNws to Compare C and Java TCP-Socket Performance
• Abstract:As research and implementation continue to facilitate high performance computing in Java, applications can benefit from resource management and prediction tools. In this work, we present such a tool for network round trip time and bandwidth between a user’s desktop and any machine running a web server . JavaNws is a Java implementation and extension of a powerful subset of the Network Weather Service (NWS), a performance prediction toolkit that dynamically characterizes and forecasts the performance available to an application. However, due to the Java language implementation and functionality (portability, security, etc), it is unclear whether a Java program is able to measure and predict the network performance experienced by C-applications with the same accuracy as an equivalent C program. We provide a quantitative equivalence study of the Java and C TCP-socket interface and show that the data collected by the JavaNws is as predictable as, that collected by the NWS (using C).
• Chandra Krintz, Rich Wolski
• Department of Computer Science and Engineering University of California, San Diego and Computer Science Department University of Tennessee, Knoxville
• emailckrintz@cs.ucsd.edu, rich@cs.utk.edu
• Original PDF: C485krintz/paper.pdf