My Point of View about Bandwidth Sharing

Bin Wang

Outline

• Oktopus (Sigcomm 2011)

• TIVC (Sigcomm 2012)

• Seawall (NSDI 2011)

• Faircloud (Sigcomm 2012)

• Hadrian (NSDI 2013)

Min-Guarantee

• Each VM should be guaranteed a minimum bandwidth. (Oktopus et al.)

Calculate

VM Bandwidth VM Placement

Bulid Virtual Data Center

Oktopus [Hitesh Ballani et al. Sigcomm 2011]

• Virtual Cluster• <N, B>

• Virtual Oversubscribed Cluster

• <N, B, S, O>

BNBswitch

BNBgroup

O

BSBlink

O

BNBroot

TIVC [Di Xie et al. Sigcomm 2012]

• Temporally-interleaved Virtual Cluster

• Example: Single Peak <N, T, Bb, P>, where P=(T1, T2, B)

]T ,[T B

T] ,T [or ]T [0, BB(t)

21

21b

t

t

Network Proportionality

• The bandwidth allocated to a tenant should be proportional to its payment. (Seawall et al.)

• Per-flow allocation [B. Briscoe Sigcomm 2007]

• unfairness for jot flows

• Per-source allocation [Seawall Alan Shieh et al. NSDI 2011]

• asymmetric for bisection bandwidth allocation

• (similar to per-destination allocation)

High Utilization

• Spare network resources should be allocated to tenants with demand. (FairCloud et al.)

• Per-VM allocation [Gatekeeper H. Rodrigues et al. WIOV 2011]

• violate min-guarantee & proportionality• Per-SD allocation [FairCloud Lucian Popa et al. Sigcomm 2012]

[Hadrian Hitesh Ballani et al. NSDI 2013]

Good Allocation Strategies (1)

• Work conservation: As long as there is at least a tenant that has packets to send along link L, L cannot be idle. (FairCloud)

Good Allocation Strategies (2)

• Strategy-proofness: Tenants cannot improve their allocations by lying about their demands. (FairCloud)

Good Allocation Strategies (3)

• Utilization incentives: Tenants are never incentivized to reduce their actual demands on uncongested paths or to artificially leave links underutilized. (FairCloud)

ξC-AA 2 43

links. on two 22/3 bandwidth

get total will

ξ-C

A

links. on two 2/ bandwidth

get totalonly will

ξC

B

C-ξC 2 to2 from decrease n willutilizatio wholeThe

Good Allocation Strategies (4)

• Communication dependencies: A tenant’s communication dependency is a list of other tenants or peers that the tenant expects to communicate with. (Hadrian)

If, i) P: {Q}, ii) Q: {P, R}, iii) R: {*}, R cannot communicate with P.

Good Allocation Strategies (5)

• Min-guarantee: Total flows do get their minimum bandwidths. (Hadrian)

Good Allocation Strategies (6)

• Symmetry: The reverse allocation of each flow should match its original (forward) allocation. (FairCloud)

None of the state of art includes all the above issues.

• None of them is strategy-proofness because all of them are static allocations.

Hadrian

FairCloud

• PS-L:

• PS-P:

Strategy-proofness is requisite because it prevents malicious allocation actions.

My points of view

• Link incentives: Useful link will be work conservation as soon as possiable.

• Preferential policy: The last allocation statement, if triggered by newly allocations, should not be largely changed in a period.

• First-fit: The initial source&destination VMs through the link will acquire preferential policy.

• Other factors: Our proposal should not violate min-guarantee et al.

First Fit--Per-SD allocation

• Assume each VM has the same min-guarantee as 1.

00 , 1 LYXW YX

is a set of all VMs belonging to the proximate link l on first-fit period0L

Link l

p

q

r1

r2

r3

r4

For example, 10000

4321 rqrqrqrp WWWW

First Fit--Per-SD allocation

• When adding the transfer p'-r5, because it is also the first-fit, it's allocation weight:

Link l

p

q

r1

r2

r3

r4

P’ r5

10' 5

rpW

}or |,{ }1

1 ,1min{ 11

iii

iiYX LYLXYXW

i

The allocation strategy for newly D/S from the latest S/D.

is the number of the newly D/S from X at statement i.

i is the number of the decreased old S/D from X at statement i.

Instance

Link l

p

q

r1

r2

r3

r4

Link l

p

q

r1

r2

r3

r4

P’ r5

r6

10000

4321 rqrqrqrp WWWW

1 5.0}1 ,11

01min{

1

0'

1

0000

56

4321

rprq

rqrqrqrp

WW

WWWW

Instance (2)

Link l

p

q

r1

r2

r3

r4

P’ r5

r6

Link l

p

q

r1

r2

r3

r4

P’ r5

r6

r7

r8

p1

5.0}1 ,11

01min{

1}1 ,21

31min{

1

22

11

87

pr

rqrq

W

WW

Instance (3)

Link l

p

q

r1

r2

r3

r4

P’ r5

r6

}, W{WX-YLYLX Y-XX-Yii min :is of weight theso , and If

Link l

p

q

r1

r2

r3

r4

P’ r5

r6

r7

r8

0.5 is weight actural theSo

,1}1,31

31min{ e,perspectiv s' theFrom

,5.0}1 ,11

01min{ e,perspectiv s' theFrom

1

1

qp

qp

Wq

Wp

Disscussion

• The proposal is strategy-proofness.

Deeply increasing allocation does not affect the last allocation most.

• Deeply decreasing allocation will affect the benefit of the actor.

The strategy encourages the balance of the increasing&decreasing.

First-fit at Tenant Level

Link l

p

q

r1

r2

r3

r4

)} Z, ( ,or |,{ }1

1 ,1min{ i

i

iiYX LTZZTYTXYXW

10000

4321 rqrqrqrp WWWW

Link l

p

q

r1

r2

r3

r4

P’ r5

r6

5.0}1 ,11

01min{ 5.0}1 ,

11

01min{

1

1'

1

0000

56

4321

rprq

rqrqrqrp

WW

WWWW

First-fit at Tenant Level Case 1

}, W{WX-Y

LTTTYTX

Y-XX-Y

i

min :is of weight theso

, in element have and both , and If 2121

Link l

p

q

r1

r2

r3

r4

P’ r5

r6

Link l

p

q

r1

r2

r3

r4

P’ r5

r6

r7

r8

p1

0.5 is weight actural theSo

,1}1,31

31min{ e,perspectiv s' theFrom

,5.0}1 ,11

01min{ e,perspectiv s' theFrom

11

11

11

11

rp

rp

Wr

Wp

First-fit+Payment-guarantee

• The proportionality should represent VMs payment-guarantee. That means VMs with smaller minimal bandwidth should not acquire the profit fro

m VMs with larger one. (Hadrian)

Link l

p

q

r1

r2

r3

r4i

ii

1

1}

1

1 ,1min{ } ,min{

ii

rp

i

ir

ipi

W

BB

Proposal ComparisonWork conser

vationStrategy-proofness

Comm. depe.

Utilization incentives

Min-guarantee

Symmetry

Oktopus × × × × × ×Per-source √ × × × × ×Per-flow × × × × × ×

PS-L √ × × √ × √PS-P √ × × √ √ √

Hadrian √ × √ √ √ √

First-fit √ √ × √ x √

First-fit+payment

√ √ √ √ √ √

Future Work

• Consider the deployment in the tree-based topology/BCube

• Simulate on Estinet (compared with FairCloud, per-source, per-flow, Hadrian)

• Testbed (3 hops communication & Fat-tree)

Thanks