CPSC 601. 38: Project Brainstorming Session Carey Williamson Department of Computer Science University of Calgary 1
PROJECT OVERVIEW H A “typical” course project might involve: – design/build/obtain appropriate testbed, environment, or platform for your project – extend/customize as needed – obtain relevant data/measurements needed – design suitable experiment: clear goal, identify factors, levels, performance metrics – obtain and present (new/interesting) results 2
Some Data Sets and Traces H H H H Web server access logs (1996) Web proxy access logs (1998) MPEG video traces (20 x 40, 000 frames) ISP measurements (4 traces, 1 -2 minutes) Frame. Relay/ATM traces (5 traces) Bellcore Ethernet LAN trace (1989) TCP/IP packet traces (LBL, 24 hours, 1. 8 M) See also the “Internet Traffic Archive” 3
Some Available Simulators H H H H ATM-TN simulator (ATM cell-level) Clustered Web server simulator (dws) Web proxy caching hierarchies (Muda) Distributed Web proxy simulator IP-TN simulator (U of C) IP-TNE (emulator) (U of C) LBL’s ns-2 simulator (TCP packet level) 4
Some Useful Tools H H H H Synthetic Web proxy workload generation Web client traffic model (mosaic, 1995) LRD traffic analysis (R/S, V-T, AC, etc) GUI for traffic modeling/analysis (syn. Traff) Wavelet-based traffic model (Ram) Synthetic MPEG video trace generation Sim. Kit programming language (Uof. C) 5
Issues and Ideas H Improving/extending Pro. WGen – temporal locality; document mods; scaling H H H Web proxy caching hierarchies Hierarchical vs distributed caching Web response time modeling Improving network TCP flow model (dws) Wavelet-based traffic forecasting Wavelength assignment in WDM networks 6
1. ATM-TN System Overview Input Data Set ATM-T ATM-N TMF Sim. Kit Output Data Set workstation Report Generation Scripts Report ATM MF Warp. Kit ESS SMTW UNIX Hardware SPARC, KSR, SGI
CBR Poisson Ethernet JPEG/MPEG Web TCP/IP/AAL 5 ABR Traffic Models Switch and Network Models ATM MF TMF Sim. Kit Warp. Kit SMTW X Wai. Kit ESS UNIX Operating System Sequential: UNIX Workstations (SGI, SPARC, DEC, HP) Parallel: SGI Power Challenge, SPARC 1000
2. Distributed Web Server Model 1 2 File Server 3 Dispatcher (Front End) Web Clients N Server Nodes 9 Cache Manager Object Store
Server Parameters H H H Num server nodes Mem cache size Disk cache size Cache replacement policy for each (LRU, LFU, SIZE, DUAL) Comm. latency Cache consistency 10 H H H Dispatch policy (DNS, RR, Redirect, Load) Request distribution policy (requests, bw, conns, affinity, . . . ) Server bandwidth Per-request bandwidth BW scaling model
Performance Metrics H Load balancing – – – H H Cache performance – document hit rate – byte hit rate requests bytes bandwidth connections clients H H Relative improvement versus RR, Rand, etc 11 H H Comm. overhead Avg response time Avg inflation factor Others. . .
3. Web Proxy Caching Model Web Servers Aggregate Workload Proxy server Web Clients 12
Hierarchical Proxy Caching Simulation Model Web Servers Complete Overlap Partial Overlap (50%) Proxy server Upper Level (Parent) Proxy server Lower Level (Children) No Overlap Web Clients 13
Factors and Levels H H Cache size Cache Replacement Policy – Recency-based LRU – Frequency-based LFU-Aging – Size-based GD-Size H Workload Characteristics – One-timers, Zipf slope, tail index, correlation, temporal locality model 14
Pro. WGen Conceptual View LLCD F Zipf P Correlation -1 0 +1 s r Pro. WGen Software Input Parameters 1 Z a 15 c L Synthetic Workload
Key Workload Characteristics H H H “One-timers” (60 -70% useless!!!) Zipf-like document referencing popularity Heavy-tailed file size distribution (i. e. , most files small, but most bytes are in big files) Correlations (if any) between document size and document popularity (debate!) Temporal locality (temporal correlation between recent past and near future references) [Mahanti et al. 2000] 16
Скачать презентацию CPSC 601 38 Project Brainstorming Session Carey Williamson
e836d3e36c418aa0a8b2e8cd06c6c715.ppt