CSE 691: Energy-Efficient ComputingLecture 3

SLEEP: full-systemAnshul Gandhi

1307, CS buildinganshul@cs.stonybrook.edu

Number of servers worldwide:

Google: 1-2%

2013:Google: > 1M serversMicrosoft: ~1M serversAmazon: <1M servers

Tencent: +700K servers!

power_nap paper

US data centers: 100 billion kWh by 2011?? $$

Server utilization: <30%

Idle server power: 60% of peak

Idle periods: ~secondswhy important?

What does 30% utilization mean?

Utilization data

Existing techniques1. Consolidation

2. Sleep states

3. Throttling (DVFS)

PowerNap1. Simple idea (only 2 states)• Minimize power draw in sleep• Fast transitions

2. Model (power and response time)

3. PowerNap vs DVFS

4. RAILS

agile paper

agile• PowerNap was NOT implemented

agile took first REAL step towards that

• Static consolidation vs Dynamic consolidation

• How to minimize latency penalties of dynamic consolidation? 3 ideas.

• agile: dynamic virtualization +

PowerNap implementation

agile: main problem

agile: low-power statesTurbo

C0 P states T states

C1

C1E

C2

C3

S0 C6

S1

S2

S3

G0 S4

G2 S5

G3

agile: power vs. latency

agile: dynamic consolidation1. Host power-up2. VM migration3. Host power-down