1. Utility Computing Amin Vahdat Internet Systems and Storage Group http://issg.cs.duke.edu vahdat@cs.duke.edu

2. OPUS: An Overlay Utility Service l Dynamically allocate resources to competing services Based on changing application and network characteristics, SLAs l Create topology based app requirements Bandiwdth, latency, loss rate, cost ($) sensitivity App demand Overlay node Peering

3. Current Questions l What are the proper SLA’s for specifying utility for competing applications l Allocate resources among competing applications based on changing network/application conditions l Overlays that dynamically trade “performance” for “cost” Two-metric network optimization (NP-complete with centralized information) Scale to 10,000 nodes l Service overlays versus application overlays

4. ModelNet l Step 1: specify target wide- area topology Graph with edges augmented to include BW, latency, loss rates, etc. l Step 2: map topology to router core Graph partitioning Accuracy? Congestion? l Step 3: run real code on edge nodes Subjected to specified network char’s Gb Switch 100Mb Switch Edge Nodes Router Core

5. Open Questions and Status l How to introduce noise into emulation environment? l Scalability versus accuracy How far can system scale? Target: 10 node core (gigabit interconnect), 100 edge nodes l Current status Reproduced CFS results from SOSP 2001 paper Using RON network connectivity information Figures 6, 7, 8 4000-node gnutella network