Characterizing and optimizing TPC-C workloads on large-scale systems using SSD arrays在大规模系统上优化 TPC-C 评测程序

Transaction processing performance council benchmark C (TPC-C) is the de facto standard for evaluating the performance of high-end computers running on-line transaction processing applications. Differing from other standard benchmarks, the transaction processing performance council only defines specifications for the TPC-C benchmark, but does not provide any standard implementation for end-users. Due to the complexity of the TPC-C workload, it is a challenging task to obtain optimal performance for TPC-C evaluation on a large-scale high-end computer. In this paper, we designed and implemented a large-scale TPC-C evaluation system based on the latest TPC-C specification using solid-state drive (SSD) storage devices. By analyzing the characteristics of the TPC-C workload, we propose a series of system-level optimization methods to improve the TPC-C performance. First, we propose an approach based on SmallFile table space to organize the test data in a round-robin method on all of the disk array partitions; this can make full use of the underlying disk arrays. Second, we propose using a NOOP-based disk scheduling algorithm to reduce the utilization rate of processors and improve the average input/output service time. Third, to improve the system translation lookaside buffer hit rate and reduce the processor overhead, we take advantage of the huge page technique to manage a large amount of memory resources. Lastly, we propose a locality-aware interrupt mapping strategy based on the asymmetry characteristic of non-uniform memory access systems to improve the system performance. Using these optimization methods, we performed the TPC-C test on two large-scale high-end computers using SSD arrays. The experimental results show that our methods can effectively improve the TPC-C performance. For example, the performance of the TPC-C test on an Intel Westmere server reached 1.018 million transactions per minute.     

短网址技术在浙江省气象短信业务中的应用

随着3G网络的发展及智能手机的普及,各类气象服务终端的推广和服务途径的拓展,公众获取气象信息途径日趋普及,对近年来发展起来的气象短信业务造成严重的冲击。本文旨在通过对3G网络发展的分析,研究利用短网址技术扩展气象短信服务内容,寻求缓解短信订制用户下滑的办法,并进行相应的尝试。     

桃汛试验对万家寨水库冲淤影响分析

通过对桃汛试验前后两个时段对比分析,认为桃汛试验没有增加万家寨库区淤积;库区淤积形态有所调整,淤积三角洲向坝前推进,库尾段平均河底高程没有抬升.     

雅砻江锦屏梯级水电站鱼类增殖放流站设计

为了缓解水电工程建设对鱼类资源的不利影响,设置鱼类增殖放流站是其解决方法之一.现以雅砻江锦屏梯级水电站建设为例,介绍其鱼类增殖放流站的设计方案,内容主要包括鱼类资源概况、鱼类增殖站建设的必要性、鱼类增殖站方案规划、运行管理、放流效果监测与评估等五个方面,可供其他水电工程鱼类保护设计参考.     

Multiconsensus of second order multiagent systems with directed topologies

A novel multiconsensus problem is introduced in multiagent systems. The states of multiple agents in each subnetwork asymptotically converge to a consistent value with information exchanges among subnetworks. The multiconsensus problem of second order multiagent systems with directed topologies is studied. Three linear protocols are proposed to solve the multiconsensus problem. Necessary and sufficient conditions are derived based on matrix theory. Simulations are provided to demonstrate the effectiveness of the theoretical results.     

现代远程协作学习系统的设计与实现

目前的远程教学中主要依赖的信息共享、个体学习、有限交互的模式,已经不能满足学习者对学习质量越来越高的期望。在此,提出一个协作学习模型。这种协作方式可以使学生在信息交流的过程中,更好地了解他人的观点、方法和建议,促进自己的学习。同时,这种模型也为基于Web的信息交流提供新的协作方式。