1. -1- System Software Research Lab. Resource Management Policies for E-commerce Servers Daniel A. Menasce, Virgilio A. F. Almeida 2 nd Workshop on Internet Server Performance, 1999 2000. 11. 29 SSLAB, EE Dept, KAIST 박상호 기존의 resource management 와 다른 metric(revenue throughput) 을 제안하고, 제안한 metric 을 극대화하기 위해 client 들의 session 특성을 분석하고, 이를 resource Management 에 적용하였다.

2. -2- System Software Research Lab. Content ▣ Introduction ▣ E-commerce workload ▣ New Resource Management Policies ▣ Framework ▣ Performance ▣ Conclusions & critiques

3. -3- System Software Research Lab. Introduction ▣ Resource management ◈ Resource : CPU, disk, network bandwidth ◈ Traditional QoS metric –Client-side : response time –Server-side : throughput ◈ Utmost important QoS metric for E-commerce servers –Revenue throughput : $/sec –Trade-off between throughput and response time –Poor response time  Customers leave the site  Reduction of revenue

4. -4- System Software Research Lab. E-commerce workloads(Cont’d) ◈ Revenue throughput : $/sec ◈ Potential lost revenue/sec : $/sec ▣ Session : sequence of requests of different types ◈ Browse, search, select, add to the shopping cart and pay ◈ CBMG(Customer Behavior Model Graph) ◈ Occasional buyer / heavy buyer –V = (Vb, Vs, Va, Vt, Vp) (average number of visits to the state) –V’ – Vhp = V x P (P : 5x5 matrix) –Vo=(6.76, 6.76, 0.14, 0.04, 2,73), Vh=(2.71, 2.71, 0.37, 0.11, 1.12) –Average session length = S = 1 + Vb + Vs + Va + Vt + Vp –So = 17.45, Sh = 8.03 –Buy to visit ratio = BV = Vp of occasional & heavy –BV = 0.9 x 0.04 + 0.1 x 0.11 = 0.047 –Upper bound on the revenue throughput

5. -5- System Software Research Lab. E-commerce workloads Occasional buyer

6. -6- System Software Research Lab. New Resource Management Policies(Cont’d) ◈ Priority-based resource management : priorities change dynamically –State in which a customer is –Session length –Amount of money in his/her shopping cart * User profile h : Homepage b : Browse s : Search t : Select a : Add to cart p : Pay

7. -7- System Software Research Lab. ◈ Managed resources –CPU –Processor sharing for classes Medium and Low –Ordered by $sc for the High –Disks –FIFO for classes Medium and Low –Ordered by $sc for the High New Resource Management Policies(Cont’d)

8. -8- System Software Research Lab. Framework(Cont’d) ◈ Session generator –SURGE ◈ Http requests –Current state, transition probability and think times –System response : poor response time -> customers leave the site –# of retries : (Occasional, Heavy) = (1,3) –Timeout = c2(state) + c1 * session_length c2(b,s,t,a,p) = (9,9,8,8,30), c1 = 0.1

9. -9- System Software Research Lab. Framework(Cont’d) ◈ Simulation model –Electric bookstore Think timeAll transitions : 15 sec Select to Add : 45 sec, Add to Pay : 25 sec, Search to Select : 30 sec Percent of Technical Books Selected20 % Book Price Parameters DistributionsTruncated Gaussian Average PricesTechnical Books Non-technical books $45 $18 Price rangeTechnical Books Non-technical books $5 - $100 $5 - $60 Searchby author By keyword 60% 40% Avg. size of pages (kB) (returned by Search results) By author Technical : 11 Non-technical : 16 By keyword Technical : 20 Non-technical : 25 Avg. size of pages (kB) (returned by Browse requests) 20

10. -10- System Software Research Lab. Framework

11. -11- System Software Research Lab. Performance(Cont’d)

12. -12- System Software Research Lab. Performance

13. -13- System Software Research Lab. Conclusions & critiques ▣ Conclusions ◈ Novel metrics which combine the two views(client and server) ◈ CBMG(Customer Transition Model Graph) to address the e-commerce workload characterization issue ◈ Adaptive scheduling policy ▣ Critiques ◈ Real-environment ◈ User profile : use cookie