“Scalable and Topologically-aware Application-layer Multicast”

2004.1.29

Yusung Kimyskim@cosmos.kaist.ac.kr

Korea Advanced Institute of Science and Technology

17th APAN meetings / Jt Techs workshop

Korea Advanced Institute of Science and Technology

Outline

1. Introduction 2. Related works

3. Problem definition4. Model5. Performance evaluation6. Analysis7. Conclusion8. Future workReference

Korea Advanced Institute of Science and Technology

1. Introduction : Logistical Networking

Logistical Networking is an end-to-end approach for globally scalable network storage [Beck 02] It is applied to large-scale distributed network storage system such as web

caching, FTP mirroring, Content Distribution Network (CDN), and Data Grid etc.

A scalable and efficient one-to-many data transfer mechanism is necessary when moving data to large-scale distributed nodes on Logistical Networking

Logistical Backbone

Korea Advanced Institute of Science and Technology

1. Introduction : Application-layer Multicast

IP multicast is an efficient mechanism for multipoint data transfer, but deployment has not been widely adopted yet [Banerjee 02]

Application-layer Multicast does not change the network infrastructure, instead it implements multicast forwarding functionality at end-host.

Korea Advanced Institute of Science and Technology

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H : Host R : Router Number : latency

Total latency : 30 Total latency : 32

2. Related works - Application-layer Multicast approaches

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1) Centralized approach [Pendarakis 01] 2) Tree first approach [Zhang 02]

•Using global topology information• Not scalable • Using partial topology information

• Scalable

H Host : multicast participant

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Korea Advanced Institute of Science and Technology

3. Problem definition Lack of global topology information cause data-paths to include

unnecessary high-latency hops, it increases the usage of network resource and delays data transfer time

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b. Comparison between two application-layer data pathsKorea Advanced Institute of Science and Technology

4. Model

H Host : multicast participant

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L(2,1,3) L(2,3,1)

L(3,2,1)L(3,1,2)

L ( landmark 1, landmark 2, landmark 3 ) : order of near landmarks

Adding landmark scheme to tree-first approach for the scalable application-layer multicast, construct topologically-aware data paths

Sourcelandmark 1

landmark 3

landmark 2

Korea Advanced Institute of Science and Technology

Seoul Univ.

KAIST

Tokyo Univ.

KOREA

JAPAN

5. Performance evaluation5.1 Topology generation methodology

Methodology Logistical Backbone experiment [Lbone]

Inet : topology generator [Inet]

Number of nodes

170 10,000

Network costLatency : 10 KB transfer time

instead of RTT [Jannotti 00] Latency : weight

( allocated bye Inet )

Number of landmarks

6 20

Number of receivers

5 ~ 155 10 ~ 8,000

Korea Advanced Institute of Science and Technology

5. Performance evaluation

5.1 Topology generation methodology

5.2 Result I : link latency

5.3 Result II : path stretch 5.4 Reuslt III : number of control message

* Stretch (relative delay penalty) [Chu 00] : the ratio of the delay from the source to the member along the application-layer data path, to the delay of the direct unicast path

•Control messages (control overhead) [Banerjee 02] : messages exchanged between all nodes to construct data path

Korea Advanced Institute of Science and Technology

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)5.2 Result I : link latency - on Logistical Backbone experiment

Comparison on average link latency ( with 6 landmarks )

• less average link latency than that of tree first approach

UnicastTree first approach

Centralized approachLandmark based approach

Korea Advanced Institute of Science and Technology

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5.2 Result I : link latency - on Inet simulation

Comparison on average link latency (with 20 landmarks)

IP multicast

• less average link latency than that of tree first approach

UnicastTree first approach

Centralized approachLandmark based approach

Korea Advanced Institute of Science and Technology

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h5.3 Result II : path stretch - on Inet simulation

Tree first approach

Centralized approachLandmark based approach

Comparison on average path streth (with 20 landmarks)

• significantly reduced average path stretch

Korea Advanced Institute of Science and Technology

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s5.4 Result III : number of control messages - on Inet simulation

Comparison on number of control messages (with 20 landmarks)

• Case of receivers above 30, the number of control messages of landmark based approach is similar to that of tree first approach

Tree first approach

Centralized approachLandmark based approach

Korea Advanced Institute of Science and Technology

6. Analysis

Centralized approach

[Pendarakis 01]

Tree-first approach

[Zhang 02]Landmark based

approach

Data path construction

Mesh basedmeasurement

Tree based measurement

Tree based measurement

with landmark

ScalabilityO (n²)

at one nodeO (logn)

at each node

O (logn)

at each node

Topology awareness

Global awareness Partial awarenessLimited global

awareness

Additionalinfrastructure

None NoneSetting constant

number of landmarks

Korea Advanced Institute of Science and Technology

7. Conclusion

+ Contribution

1) We applied landmark scheme to Tree first approach

2) In results of performance evaluation, Landmark based approach can reduce the average link latency and path stretch of Tree first approach

3) Landmark based approach needs the constant number of landmarks and low number of control messages as much as Tree first approach does

=> Landmark based approach can offer the scalability of tree first approach and construct the topologically-aware data paths using landmarks.

Using topologically-aware paths, we can reduce bandwidth consumption and data transfer time

+ Limitation

=> An additional landmark infrastructure is necessary

Korea Advanced Institute of Science and Technology

8. Future work

Existing researches for application-layer multicast considered network latency to construct data pathsBandwidth-awareness is also important to construct data paths

Korea Advanced Institute of Science and Technology

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Reference[Akamai]

[Banerjee 02]

[Beck 02]

[Faloutsos 99]

[Inet]

[Jannotti 00]

[Lbone]

[Pendarakis 01]

[Ratnasamy 02]

[Zhang 02]

Akamai, http://www.akamai.com (Accessed: 8 December 2003).

S. Banerjee, B. Bhattacharjee, and C. Kommareddy, "Scalable application layer multicast," in Proc. ACM SIGCOMM, Pittsburgh, PA, USA, August 2002.

M. Beck, T. Moore, and J. Plank, "An end-to-end approach to globally scalable network storage,“ in Proc. ACM SIGCOMM, Pittsburgh, PA, USA, August 2002.

M. Faloutsos, P. Faloutsos, and C. Faloutsos, “On power-law relationships of the Internet topology,” in Pro. ACM SIGCOMM , Cambridge, MA, USA, September 1999.

Inet, http://topology.eecs.umich.edu (Accessed: 8 December 2003).

J. Jannotti, D. K. Gifford, K. L. Johnson, M. F. Kaasheok, and J. W. O’Toole, “Overcast: reliable multicasting with an overlay network,” in Proc. 4th USENIX OSDI, San Diego, CA, USA, October 2000.

Lbone, http://loci.cs.utk.edu (Accessed: 9 December 2003).

D. Pendarakis, S. Shi, D. Verma, and M. Waldvogel, “ALMI: an application level multicast infrastructure,” in Proc. 3rd USENIX Symp. Internet Tech. and Sys., San Francisco, CA, USA, March 2001.

S. Ratnasamy, M. Handley, Richard Karp, and S Shenker, “Topologically-aware overlay construction and server selection,” in Proc. IEEE INFOCOM, New York, NY, USA, June 2002.

B. Zhang, S. Jamin, and L. Zhang, “Host multicast: a framework for delivering multicast to end users,” in Proc. IEEE INFOCOM, New York, NY, USA, June 2002.

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Appendix : number of control messages - on Logistical Backbone experiment

Tree first approach

Centralized approachLandmark based approach

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Appendix : link stress

* stress: defines the stress of a physical link as the number of identical packets it carries

landmark basedtree-first

centralizedIP multicast

Appendix: path stretch

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a. average path stretch on Logistical Backbone b. average path stretch on Inet

Tree first approach

Centralized approachLandmark based approach

Tree first approach

Centralized approachLandmark based approach

Appendix: metric [Chu 00]

Stress: defines the stress of a physical link as the number of identical packets it carries

Stretch: is the ratio of the delay between a source and a member along the overlay distribution topology, to the delay of the direct unicast path

Resource usage: defines this metric as the sum of the delay * stress product over all the links that participate in data transmissions