Comparative Study of Concurrency Control on Bulk-Synchronous Parallel Search Engines

Artículo de publicación ISIIn this paper we propose and evaluate the performance of concurrency control strategies for a parallel search engine that is able to cope efficiently with concurrent read/write operations. Read operations come in the usual form of queries submitted to the search engine and write operations come in the form of new documents added to the text collection in an on-line manner, namely the insertions are embedded into the main stream of user queries in an unpredictable arrival order but with query results respecting causality

Esquema de Paralelización Híbrida para Máquinas de Búsqueda

Con la irrupción de las CPU multicores (Chip-level MultiProcessor - CMPs-) se hace imprescindible desarrollar técnicas que aprovechen las ventajas de los CMPs para aumentar el rendimiento de las aplicaciones, haciendo uso de la computación paralela. En esta tesis se propone el diseño de una máquina de búsqueda capaz de explotar el nivel de paralelismo disponibles en los los CMPs, para el procesamiento de miles de consultas por unidad de tiempo. En particular, para esta aplicación y dada la enorme cantidad de recursos computacionales que demanda, es importante desarrollar estrategias paralelas que sean capaces de aprovechar eficientemente el hardware disponible. El diseño propuesto utiliza técnicas de computación paralela y distribuida para organizar y procesar las consultas. Se propone un esquema de paralelización híbrida basado en los paradigmas de programación BSP y OpenMP que ha sido diseñado para sacar el máximo provecho de las características multi-threading de los CMPs para máquinas de búsqueda. Se describen implementaciones y experimentos realizados sobre dos tipos de procesadores: UltraSPARC T1 de Sun Microsystem y dos nodos Intel Quad-Xeon

Two-Level scheduling algorithm for simulation servers

We present a scheme for efficiently administrating a set of distributed simulation servers which attend requests from a number of users. These can be either sequential or parallel simulation models, or random combinations of the two. We treat each server as a BSP machine and organize our scheduling strategy upon the cost prediction and computation model supported by it. Empirical results show that the proposed strategy is able to achieve near optimal performance. Our aim was to develop a mechanism which be able to work with minimum global information so that it can be utilized on Web based simulation systems.Eje: LenguajesRed de Universidades con Carreras en Informática (RedUNCI

Two-Level scheduling algorithm for simulation servers

We present a scheme for efficiently administrating a set of distributed simulation servers which attend requests from a number of users. These can be either sequential or parallel simulation models, or random combinations of the two. We treat each server as a BSP machine and organize our scheduling strategy upon the cost prediction and computation model supported by it. Empirical results show that the proposed strategy is able to achieve near optimal performance. Our aim was to develop a mechanism which be able to work with minimum global information so that it can be utilized on Web based simulation systems.Eje: LenguajesRed de Universidades con Carreras en Informática (RedUNCI

Distributed Allocation of Discrete-Event Simulation Servers

We present a scheme for eciently administrating a set of distributed simulation servers which attend requests from a number of users. These can be either sequential or parallel simulation models, or random combinations of the two. We treat each server as a BSP machine and organize our scheduling strategy upon the cost prediction and computation model supported by it. Empirical results show that the proposed strategy is able to achieve near optimal performance

Analysis of two indexing structures for textual databases

This article describes strategies devised to improve the efficiency of two classical index data structures for parallel textual databases. The design and cost evaluation is effected on top of the bulk-synchronous model of parallel computing. This allows us to compare different alternative sunder the same framework in a way which is independent of programming details and architecture of the parallel machine. Our interest is on query processing upon cluster of PCs, and thereby we focus on communication and synchronization optimizationEje: Bases de DatosRed de Universidades con Carreras en Informática (RedUNCI

Analysis of two indexing structures for textual databases

This article describes strategies devised to improve the efficiency of two classical index data structures for parallel textual databases. The design and cost evaluation is effected on top of the bulk-synchronous model of parallel computing. This allows us to compare different alternative sunder the same framework in a way which is independent of programming details and architecture of the parallel machine. Our interest is on query processing upon cluster of PCs, and thereby we focus on communication and synchronization optimizationEje: Bases de DatosRed de Universidades con Carreras en Informática (RedUNCI