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lmbench is a micro-benchmark suite designed to focus attention on the basic building blocks of many common system applications, such as databases, simulations , software development, and networking. In almost all cases, the individual tests are the result of analysis and isolation of a customer'sa ctual performance problem. These tools can be, and currently(More)
Configuring redundant disk arrays is a black art. To configure an array properly, a system administrator must understand the details of both the array and the workload it will support. Incorrect understanding of either, or changes in the workload over time, can lead to poor performance. We present a solution to this problem: a two-level storage hierarchy(More)
Research results [ROSE91] demonstrate that a log-structured file system (LFS) offers the potential for dramatically improved write performance, faster recovery time, and faster file creation and deletion than traditional UNIX file systems. This paper presents a redesign and implementation of the Sprite [ROSE91] log-structured file system that is more robust(More)
The requirements of wide-area distributed database systems differ dramatically from those of local-area network systems. In a wide-area network (WAN) configuration , individual sites usually report to different system administrators , have different access and charging algorithms, install site-specific data type extensions, and have different constraints on(More)
spend much of their time idle, and various schemes have been proposed to use this idle time productively. We have used this approach to improve overall performance in storage systems. The most common approach is to off-load activity from busy periods to less-busy ones in order to improve system responsiveness. In addition, speculative work can be performed(More)
Many new database applications require very large volumes of data. Mariposa is a data base system under construction at Berkeley responding to this need. Mariposa objects can be stored over thousands of autonomous sites and on memory hierarchies with very large capacity. This scale of the system leads to complex query execution and storage management(More)
In this paper, we present a new algorithm for aperiodic clustered-dot halftoning based on direct binary search (DBS). The DBS optimization framework has been modified for designing clustered-dot texture, by using filters with different sizes in the initialization and update steps of the algorithm. Following an intuitive explanation of how the clustered-dot(More)
Support Vector Machines (SVM), Design of Experiments (DOE), meta-parameter selection We present an algorithm for selecting support vector machine (SVM) meta-parameter values which is based on ideas from design of experiments (DOE) and demonstrate that it is robust and works effectively and efficiently on a variety of problems. Abstract— We present an(More)
The Mariposa distributed data manager uses an economic model for managing the allocation of both storage objects and queries to servers. In this paper, we present extensions to the economic model which support replica management, as well as our mechanisms for propagating updates among replicas. We show how our replica c ontrol mechanism can be used to(More)