xi
List of Figures
1.1 Total Sites Across All Domain Surveyed by Netcraft . . . . . . . . . . .
2
2.1 A Cluster based Web Server Architecture . . . . . . . . . . . . . . . . .
8
2.2 A Multi Tier Data Center Architecture . . . . . . . . . . . . . . . . . . .
10
2.3 Virtual Interface Architecture . . . . . . . . . . . . . . . . . . . . . . . .
12
3.1 The PRESS Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19
3.2 Coscheduled PRESS Model . . . . . . . . . . . . . . . . . . . . . . . . .
23
3.3 Flow Diagram for remote cache read Requests . . . . . . . . . . . . . . .
24
3.4 Three Layers of the Simulator
. . . . . . . . . . . . . . . . . . . . . . .
28
3.5 Round trip Latency Comparison . . . . . . . . . . . . . . . . . . . . . .
33
3.6 Average Latency and Throughput of a 32 node Web Cluster
. . . . . .
34
3.7 Breakdown of Accumulated Latency and Throughput of a 32 node Web
Cluster. Three Bars Represent the Results of the press via, dcs, adaptive
Models from Left to Right . . . . . . . . . . . . . . . . . . . . . . . . . .
37
3.8 Average Latency as a Function of the Replication Ratio . . . . . . . . .
42
4.1 The SSL Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
49
4.2 Latency and Throughput of a Web Server with/without SSL Protocol .
53
4.3 An Application Server Tier with the Backend Forwarding Scheme . . . .
57
4.4 Throughput Comparison between an Apache Server and the Simulator .
60
4.5 Average Latency and Throughput of a 16 node Application Server . . .
61