A Spot Capacity Market to Increase Power Infrastructure ...sren/doc/slides/slides_hpca_2018.pdf · A Spot Capacity Market to Increase Power Infrastructure Utilization in Multi-Tenant

A Spot Capacity Market to Increase Power Infrastructure Utilization in

Multi-Tenant Data Centers

Mohammad A. Islam, Xiaoqi Ren, Shaolei Ren, and Adam Wierman

This work was supported in part by the U.S. NSF under grants CNS-1551661, CNS-1565474, CNS-1518941, CPS154471, ECCS-1610471, and AitF-1637598.

Multi-tenant data centers

Utility

(Primary)

Generator

UPS

ATS

P

D

U

P

D

U

2

Managed by

operator


Utility

(Primary)

Generator

UPS

ATS

P

D

U

P

D

U

2

Managed by

individual tenants Managed by

operator


Utility

(Primary)

Generator

UPS

ATS

P

D

U

P

D

U

2

3

Multi-tenant data centers are everywhere

3

Google, Amazon, MS, Fb…

:7.8%

Enterprise:

53%

Multi-tenant:

37%

Multi-tenant data centers are everywhere

4

Who are using multi-tenant data centers?

4

25% of Apple’s servers ate in multi-tenant data centers


4



4



Data center costs breakdown

5

Source: A. Greenberg, J. Hamilton, D. A. Maltz, and P. Patel. 2008. The cost of a cloud: research problems in data center networks. SIGCOMM Comput. Commun. Rev.


5



5


Capital Expenditure

(CapEx)


5


Capital Expenditure

(CapEx) Operational Expenditure

(OpEx)


5


Capital Expenditure

(CapEx) Operational Expenditure

(OpEx)

Cost of infrastructure

Utility

(Primary)

Generator

UPS

ATS

P

D

U

P

D

U

6

Underutilization in data centers

7


7


7

Increase infrastructure utilization

8

Exploit the “spot capacity”

Increase infrastructure utilization

8

Some inspirations

• “Power routing” in ASPLOS’10 and “soft fuse” in EuroSys’09

9

Some inspirations


• “Spot instances” from Amazon

9

Some inspirations


• “Spot instances” from Amazon

• “Preemptible VM” from Google Cloud

9

Spot capacity in multi-tenant data centers

10

No centralized control


10

No centralized control Power routing,…


10

A market for spot capacity



10

A market for spot capacity


Tenants buy spot capacity from

the data center operator


10


• Flexibility for cost conscious tenants

11



Peak-based

subscription

11



Peak-based

subscription Conservative

subscription

11



Peak-based

subscription Conservative

subscription Spot capacity

11

• Tenants: • tenants with insufficient capacity reservations can temporarily

process its workloads without power capping (or cap power less frequently/aggressively than it would otherwise).


12



• Operator: • Revenue from guaranteed capacity: not affected

• Extra revenue from spot capacity


12



• Operator: • Revenue from guaranteed capacity: not affected

• Extra revenue from spot capacity

Spot capacity market is a win-win for both

tenants and operator


12

Challenges

• Spot capacity is limited and intermittent

13

Challenges


• Tenants’ spot capacity need is dynamic and invisible to the data center operator

13

Challenges


• Tenants’ spot capacity need is dynamic and invisible to the data center operator

• Infrastructure constraints require fine granularity in spot capacity allocation (e.g., rack level)

13

Goal: A scalable and runtime design

for spot capacity allocation

14

Problem formulation

• Goal: operator profit maximization

15

Rack level demand

Problem formulation


15

Price of spot

capacity

Rack level demand

Problem formulation


15

Infrastructure constraints

Price of spot

capacity

Rack level demand

Problem formulation


15

How to solve it?

16

Unknown How to solve it?

16


• Soliciting the demand curve privacy and overhead

16



• Pre-set price low level demand prediction

16



• Pre-set price low level demand prediction

• Market approach an in-between solution

16

SpotDC: spot capacity management

17

Operator Tenants


17

Spot capacity

predictions

Operator Tenants


17

Spot capacity

predictions

Operator Tenants

Response (bids)


17

Spot capacity

predictions

Operator Tenants

Response (bids)

Price and actual spot

power allocation


17

Spot capacity

predictions

Operator Tenants

Response (bids)

Price and actual spot

power allocation

Gain spot

power

Timings in SpotDC

18

Demand bidding

• A piece-wise-linear bid

19

Demand bidding


• Tenants only submit four parameters

19

Demand bidding


• Tenants only submit four parameters

• Captures tenants’ demand elasticity

19

Spot capacity prediction

• Available spot capacity prediction: max - predicted • UPS and PDU level predictions: Use previous time slot usage

as references.

20



as references.

20



as references.

20

Less than ± 2.5% change

99% of the time

Evaluation methodology

• 10 tenants with sprinting (delay sensitive) and opportunistic (delay tolerance) workloads

• Using Dynamic voltage and frequency scaling (DVFS) for power scaling.

21




21




21

Performance evaluation

22


22

Sprinting tenants drive up the price


23


23

Sprinting tenants avoid

SLO violations


23

Sprinting tenants avoid

SLO violations Opportunistic tenants

gain throughput boost

Tenants’ benefit from SpotDC

24

Tenants’ benefit from SpotDC

24

Performance boosts

with SpotDC

Operator’s extra profit

25

Operator’s extra profit

25

SpotDC is close to optimal

allocation with full information

SpotDC: Spot capacity management

A market-based approach for providing spot capacity to tenants and helping operator further increase data center utilization

26

SpotDC: Spot capacity management

A market-based approach for providing spot capacity to tenants and helping operator further increase data center utilization

26

Simple, Scalable & Efficient

Documents

A Spot Capacity Market to Increase Power Infrastructure ...sren/doc/slides/slides_hpca_2018.pdf · A Spot Capacity Market to Increase Power Infrastructure Utilization in Multi-Tenant