Hazel McKendrickSupervised by Henry Fortuna

Distributing Virtual Worlds

“How can the processing of autonomous characters in a real-time virtual environment benefit from parallelisation over multiple distributed computer systems?”

Project Overview. Processing virtual worlds Single server unsuitable Flexibility, scalability, redundancy

Distributed computing

Project Aim. Create a distributed system Divide a virtual world Update characters in it

Consider:• Processing power• Scalability, power and money saving• Flexibility

Simulation Design. World Maps Characters (thousands)

• A* Pathfinding

System Structure. Server & Worker Node architecture TCP-IP Message Passing

Node thread pool

World Division. Top-down vs Bottom-up

Microcells Smallest unit of world Nodes process several Distributed statically or

dynamically Contain and pass work

Distribution. Optimal assignment

• Can be solved with ILP - Complexity too high Two static approaches used Dynamic algorithm created

Distribution Results. Amdahl's Law 95% to 99% parallelised

0 1 2 3 4 5 6 7 8 9 10 110.000

50.000

100.000

150.000

200.000

250.000

300.000

350.000

400.000

450.000

Processing times with varying numbers of nodes

ServerNode 1Node 2Node 3Node 4Node 5Node 6Node 7Node 8Node 9

Number of computers

Proc

essi

ng ti

me

(ms)

0 1 2 3 4 5 60

0.5

1

1.5

2

2.5

3

3.5

4

Average deviation in processing times, over time

Time elapsed (minutes)

Aver

age

devi

atio

n(m

s)

Scaling Hardware. Virtual world load varies greatly Gustafson's Law Scale Hardware Improvedistribution!

(Simulated)

0 20 40 60 80 100 120 1400

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

0

1

2

3

Minimising HardwareEntities Nodes on

Time (s)

Entit

ies

Nod

es

Evaluation. Scaling nodes Dynamic distribution algorithm

• Over time Microcells Reducing hardware

Conclusion. Reduce processing times Balance load Lower power and cooling costs

Further work• Redundancy• Inter-node communications• Scaling factors

Hazel McKendrickSupervised by Henry Fortuna

Distributing Virtual Worlds

“How can the processing of autonomous characters in a real-time virtual environment benefit from parallelisation over multiple distributed computer systems?”