VPC: Multilayered View

1
VPC Multilayered View
S2
S1
S3
S5
S4
VPC SPC È MPC
HBN
SPC - Primary copy on a stationary
node MPC - Primary copy on a mobile
host
. . .
SPC2
MPC1
MPC2
SPC1
Zone of Influence
2
VPC Simulation

• Primary Copy Method vs. VPC
• Transaction processing system with read-only,
  write-only, write-read requests
• Assumptions
• Simulation parameters
• number of hosts (both stationary mobile)
• number of data objects
• transaction events, etc
• Transaction behaviour
• Simulation outputs
• VPC outperforms PC for applications
• write- dominated
• fixed set of transactions
• Tx - connection/disconnection ratio increases

3
VPC Performance Comparison
Cost ratio 1220 , Transaction to
connection/disconnection
ratio 11
300
100
90
250
80
70
200
60
150
50
Cost per committed transaction ( Cost -Tx )
Total number of committed transactions (
Com - Tx )
40
100
30
20
50
10
0
0
0
20
40
60
80
100
of writes
COST-
COST-
COM-
COM-
Tx-
Tx-
Tx-PC
Tx-PC
VPC
VPC