Jorge Londoo Azer Bestavros and ShangHua Teng Computer Science - - PowerPoint PPT Presentation

Jorge Londoño

Azer Bestavros and Shang‐Hua Teng

Computer Science Department Boston University USENIX HotCloud’09

• In the Infrastructure as a Service market,

providers offer fixed‐sized instances

• Provider’s profit = number of instances sold;

no incenRve to colocate customers

• VirtualizaRon enables customers to colocate

to reduce costs without QoS compromises

• Customers’ selfishness reduces colocaRon to

a strategic game

A $ P $ P CPU I/O CPU I/O B

A

Customers’ Strategic AcRons

$ P $ P CPU I/O CPU I/O $ fP $ (1‐f)P C $P $ f’P $ (1‐f’)P B

• General Coloca+on Game: MulRple resources
• ver mulRple processes per customer

– No guarantee of Nash Equilibrium (NE)

• Process Coloca+on Game: MulRple resources
• ver a single process (e.g., VM) per customer

– Converges to a NE – Price of Anarchy = 3/2 (if homogeneous resources) 2 (otherwise)

Median over all experiments Worst‐case experiment

Median over all experiments Worst‐case experiment

• Strategic Services: To facilitate colocaRons,

e.g., allowing users to find each other, compute strategic responses, …

• OperaRonal Services: To enforce outcomes
• f colocaRon game, e.g., reconfiguraRon,

accounRng, …