Clustered%20Web%20Server%20Model

1
Clustered Web Server Model
1
File Server
2
3
Cache
Dispatcher (Front End)
Manager
N
Object Store
Web Clients
Server Nodes
2
Server Parameters

• Num server nodes
• Mem cache size
• Disk cache size
• Cache replacement policy for each (LRU, LFU,
  SIZE, DUAL)
• Comm. latency
• Cache consistency

• Dispatch policy (DNS, RR, Redirect, Load)
• Request distribution policy (requests, bw, conns,
  affinity, ...)
• Server bandwidth
• Per-request bandwidth
• BW scaling model

3
Performance Metrics

• Load balancing
• requests
• bytes
• bandwidth
• connections
• clients
• Relative improvement versus RR, Rand, etc

• Cache performance
• document hit rate
• byte hit rate
• Comm. overhead
• Avg response time
• Avg inflation factor
• Others...