large graph miningchristos/talks/11-vertica/foils/... · 2011. 8. 7. · cmu scs large graph mining...

141
CMU SCS Large Graph Mining Christos Faloutsos CMU

Upload: others

Post on 21-Feb-2021

3 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Large Graph Mining

Christos Faloutsos CMU

Page 2: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Thank you!

•  Stephen Walkauskas

Vertica'11 C. Faloutsos (CMU) 2

Page 3: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 3

Our goal:

Open source system for mining huge graphs:

PEGASUS project (PEta GrAph mining System)

•  www.cs.cmu.edu/~pegasus •  code and papers

Vertica'11

Page 4: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 4

Outline

•  Introduction – Motivation •  Problem#1: Patterns in graphs •  Problem#2: Tools •  Problem#3: Scalability •  Conclusions

Vertica'11

Page 5: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 5

Graphs - why should we care?

Internet Map [lumeta.com]

Food Web [Martinez ’91]

Friendship Network [Moody ’01]

Vertica'11

Page 6: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 6

Graphs - why should we care? •  IR: bi-partite graphs (doc-terms)

•  web: hyper-text graph

•  ... and more:

D1

DN

T1

TM

... ...

Vertica'11

Page 7: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 7

Graphs - why should we care? •  ‘viral’ marketing •  web-log (‘blog’) news propagation •  computer network security: email/IP traffic

and anomaly detection •  ....

Vertica'11

Page 8: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 8

Outline

•  Introduction – Motivation •  Problem#1: Patterns in graphs

– Static graphs – Weighted graphs – Time evolving graphs

•  Problem#2: Tools •  Problem#3: Scalability •  Conclusions

Vertica'11

Page 9: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 9

Problem #1 - network and graph mining

•  What does the Internet look like? •  What does FaceBook look like?

•  What is ‘normal’/‘abnormal’? •  which patterns/laws hold?

Vertica'11

Page 10: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 10

Problem #1 - network and graph mining

•  What does the Internet look like? •  What does FaceBook look like?

•  What is ‘normal’/‘abnormal’? •  which patterns/laws hold?

–  To spot anomalies (rarities), we have to discover patterns

Vertica'11

Page 11: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 11

Problem #1 - network and graph mining

•  What does the Internet look like? •  What does FaceBook look like?

•  What is ‘normal’/‘abnormal’? •  which patterns/laws hold?

–  To spot anomalies (rarities), we have to discover patterns

–  Large datasets reveal patterns/anomalies that may be invisible otherwise…

Vertica'11

Page 12: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 12

Graph mining •  Are real graphs random?

Vertica'11

Page 13: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 13

Laws and patterns •  Are real graphs random? •  A: NO!!

– Diameter –  in- and out- degree distributions –  other (surprising) patterns

•  So, let’s look at the data

Vertica'11

Page 14: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 14

Solution# S.1 •  Power law in the degree distribution

[SIGCOMM99]

log(rank)

log(degree)

internet domains

att.com

ibm.com

Vertica'11

Page 15: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 15

Solution# S.1 •  Power law in the degree distribution

[SIGCOMM99]

log(rank)

log(degree)

-0.82

internet domains

att.com

ibm.com

Vertica'11

Page 16: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 16

Solution# S.2: Eigen Exponent E

•  A2: power law in the eigenvalues of the adjacency matrix

E = -0.48

Exponent = slope

Eigenvalue

Rank of decreasing eigenvalue

May 2001

Vertica'11

Page 17: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 17

Solution# S.2: Eigen Exponent E

•  [Mihail, Papadimitriou ’02]: slope is ½ of rank exponent

E = -0.48

Exponent = slope

Eigenvalue

Rank of decreasing eigenvalue

May 2001

Vertica'11

Page 18: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 18

But: How about graphs from other domains?

Vertica'11

Page 19: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 19

More power laws: •  web hit counts [w/ A. Montgomery]

Web Site Traffic

in-degree (log scale)

Count (log scale)

Zipf

users sites

``ebay’’

Vertica'11

Page 20: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 20

epinions.com •  who-trusts-whom

[Richardson + Domingos, KDD 2001]

(out) degree

count

trusts-2000-people user

Vertica'11

Page 21: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

And numerous more •  # of sexual contacts •  Income [Pareto] –’80-20 distribution’ •  Duration of downloads [Bestavros+] •  Duration of UNIX jobs (‘mice and

elephants’) •  Size of files of a user •  … •  ‘Black swans’ Vertica'11 C. Faloutsos (CMU) 21

Page 22: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 22

Outline

•  Introduction – Motivation •  Problem#1: Patterns in graphs

– Static graphs •  degree, diameter, eigen, •  triangles •  cliques

– Weighted graphs – Time evolving graphs

•  Problem#2: Tools Vertica'11

Page 23: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 23

Solution# S.3: Triangle ‘Laws’

•  Real social networks have a lot of triangles

Vertica'11

Page 24: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 24

Solution# S.3: Triangle ‘Laws’

•  Real social networks have a lot of triangles –  Friends of friends are friends

•  Any patterns?

Vertica'11

Page 25: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 25

Triangle Law: #S.3 [Tsourakakis ICDM 2008]

ASN HEP-TH

Epinions X-axis: # of participating triangles Y: count (~ pdf)

Vertica'11

Page 26: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 26

Triangle Law: #S.3 [Tsourakakis ICDM 2008]

ASN HEP-TH

Epinions

Vertica'11

X-axis: # of participating triangles Y: count (~ pdf)

Page 27: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 27

Triangle Law: #S.4 [Tsourakakis ICDM 2008]

SN Reuters

Epinions X-axis: degree Y-axis: mean # triangles n friends -> ~n1.6 triangles

Vertica'11

Page 28: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 28

Triangle Law: Computations [Tsourakakis ICDM 2008]

But: triangles are expensive to compute (3-way join; several approx. algos)

Q: Can we do that quickly?

details

Vertica'11

Page 29: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 29

Triangle Law: Computations [Tsourakakis ICDM 2008]

But: triangles are expensive to compute (3-way join; several approx. algos)

Q: Can we do that quickly? A: Yes!

#triangles = 1/6 Sum ( λi3 )

(and, because of skewness (S2) , we only need the top few eigenvalues!

details

Vertica'11

Page 30: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 30

Triangle Law: Computations [Tsourakakis ICDM 2008]

1000x+ speed-up, >90% accuracy

details

Vertica'11

Page 31: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Triangle counting for large graphs?

Anomalous nodes in Twitter(~ 3 billion edges) [U Kang, Brendan Meeder, +, PAKDD’11]

31 Vertica'11 31 C. Faloutsos (CMU)

Page 32: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Triangle counting for large graphs?

Anomalous nodes in Twitter(~ 3 billion edges) [U Kang, Brendan Meeder, +, PAKDD’11]

32 Vertica'11 32 C. Faloutsos (CMU)

Page 33: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

EigenSpokes B. Aditya Prakash, Mukund Seshadri, Ashwin

Sridharan, Sridhar Machiraju and Christos Faloutsos: EigenSpokes: Surprising Patterns and Scalable Community Chipping in Large Graphs, PAKDD 2010, Hyderabad, India, 21-24 June 2010.

C. Faloutsos (CMU) 33 Vertica'11

Page 34: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

EigenSpokes • Eigenvectors of adjacency matrix

  equivalent to singular vectors (symmetric, undirected graph)

34 C. Faloutsos (CMU) Vertica'11

Page 35: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

EigenSpokes • Eigenvectors of adjacency matrix

  equivalent to singular vectors (symmetric, undirected graph)

35 C. Faloutsos (CMU) Vertica'11

N

N

details

Page 36: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

EigenSpokes • Eigenvectors of adjacency matrix

  equivalent to singular vectors (symmetric, undirected graph)

36 C. Faloutsos (CMU) Vertica'11

N

N

details

Page 37: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

EigenSpokes • Eigenvectors of adjacency matrix

  equivalent to singular vectors (symmetric, undirected graph)

37 C. Faloutsos (CMU) Vertica'11

N

N

details

Page 38: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

EigenSpokes • Eigenvectors of adjacency matrix

  equivalent to singular vectors (symmetric, undirected graph)

38 C. Faloutsos (CMU) Vertica'11

N

N

details

Page 39: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

EigenSpokes •  EE plot: •  Scatter plot of

scores of u1 vs u2 •  One would expect

– Many points @ origin

– A few scattered ~randomly

C. Faloutsos (CMU) 39

u1

u2

Vertica'11

1st Principal component

2nd Principal component

Page 40: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

EigenSpokes •  EE plot: •  Scatter plot of

scores of u1 vs u2 •  One would expect

– Many points @ origin

– A few scattered ~randomly

C. Faloutsos (CMU) 40

u1

u2 90o

Vertica'11

Page 41: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

EigenSpokes - pervasiveness • Present in mobile social graph

 across time and space

• Patent citation graph

41 C. Faloutsos (CMU) Vertica'11

Page 42: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

EigenSpokes - explanation

Near-cliques, or near-bipartite-cores, loosely connected

42 C. Faloutsos (CMU) Vertica'11

Page 43: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

EigenSpokes - explanation

Near-cliques, or near-bipartite-cores, loosely connected

43 C. Faloutsos (CMU) Vertica'11

Page 44: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

EigenSpokes - explanation

Near-cliques, or near-bipartite-cores, loosely connected

44 C. Faloutsos (CMU) Vertica'11

Page 45: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

EigenSpokes - explanation

Near-cliques, or near-bipartite-cores, loosely connected

So what?  Extract nodes with high

scores   high connectivity  Good “communities”

spy plot of top 20 nodes

45 C. Faloutsos (CMU) Vertica'11

Page 46: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Bipartite Communities!

magnified bipartite community

patents from same inventor(s)

`cut-and-paste’ bibliography!

46 C. Faloutsos (CMU) Vertica'11

Page 47: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 47

Outline

•  Introduction – Motivation •  Problem#1: Patterns in graphs

– Static graphs •  degree, diameter, eigen, •  triangles •  cliques

– Weighted graphs – Time evolving graphs

•  Problem#2: Tools Vertica'11

Page 48: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 48

Observations on weighted graphs?

•  A: yes - even more ‘laws’!

M. McGlohon, L. Akoglu, and C. Faloutsos Weighted Graphs and Disconnected Components: Patterns and a Generator. SIG-KDD 2008

Vertica'11

Page 49: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 49

Observation W.1: Fortification Q: How do the weights of nodes relate to degree?

Vertica'11

Page 50: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 50

Observation W.1: Fortification

More donors, more $ ?

$10

$5

Vertica'11

‘Reagan’

‘Clinton’ $7

Page 51: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Edges (# donors)

In-weights ($)

C. Faloutsos (CMU) 51

Observation W.1: fortification: Snapshot Power Law

•  Weight: super-linear on in-degree •  exponent ‘iw’: 1.01 < iw < 1.26

Orgs-Candidates

e.g. John Kerry, $10M received, from 1K donors

More donors, even more $

$10

$5

Vertica'11

Page 52: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 52

Outline

•  Introduction – Motivation •  Problem#1: Patterns in graphs

– Static graphs – Weighted graphs – Time evolving graphs

•  Problem#2: Tools •  …

Vertica'11

Page 53: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 53

Problem: Time evolution •  with Jure Leskovec (CMU ->

Stanford)

•  and Jon Kleinberg (Cornell – sabb. @ CMU)

Vertica'11

Page 54: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 54

T.1 Evolution of the Diameter •  Prior work on Power Law graphs hints

at slowly growing diameter: –  diameter ~ O(log N) –  diameter ~ O(log log N)

•  What is happening in real data?

Vertica'11

Page 55: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 55

T.1 Evolution of the Diameter •  Prior work on Power Law graphs hints

at slowly growing diameter: –  diameter ~ O(log N) –  diameter ~ O(log log N)

•  What is happening in real data? •  Diameter shrinks over time

Vertica'11

Page 56: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 56

T.1 Diameter – “Patents”

•  Patent citation network

•  25 years of data •  @1999

–  2.9 M nodes –  16.5 M edges

time [years]

diameter

Vertica'11

Page 57: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 57

T.2 Temporal Evolution of the Graphs

•  N(t) … nodes at time t •  E(t) … edges at time t •  Suppose that

N(t+1) = 2 * N(t) •  Q: what is your guess for

E(t+1) =? 2 * E(t)

Vertica'11

Page 58: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 58

T.2 Temporal Evolution of the Graphs

•  N(t) … nodes at time t •  E(t) … edges at time t •  Suppose that

N(t+1) = 2 * N(t) •  Q: what is your guess for

E(t+1) =? 2 * E(t) •  A: over-doubled!

– But obeying the ``Densification Power Law’’ Vertica'11

Page 59: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 59

T.2 Densification – Patent Citations

•  Citations among patents granted

•  @1999 –  2.9 M nodes –  16.5 M edges

•  Each year is a datapoint

N(t)

E(t)

1.66

Vertica'11

Page 60: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 60

Outline

•  Introduction – Motivation •  Problem#1: Patterns in graphs

– Static graphs – Weighted graphs – Time evolving graphs

•  Problem#2: Tools •  …

Vertica'11

Page 61: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 61

More on Time-evolving graphs

M. McGlohon, L. Akoglu, and C. Faloutsos Weighted Graphs and Disconnected Components: Patterns and a Generator. SIG-KDD 2008

Vertica'11

Page 62: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 62

Observation T.3: NLCC behavior Q: How do NLCC’s emerge and join with

the GCC?

(``NLCC’’ = non-largest conn. components) – Do they continue to grow in size? –  or do they shrink? –  or stabilize?

Vertica'11

Page 63: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 63

Observation T.3: NLCC behavior Q: How do NLCC’s emerge and join with

the GCC?

(``NLCC’’ = non-largest conn. components) – Do they continue to grow in size? –  or do they shrink? –  or stabilize?

Vertica'11

Page 64: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 64

Observation T.3: NLCC behavior Q: How do NLCC’s emerge and join with

the GCC?

(``NLCC’’ = non-largest conn. components) – Do they continue to grow in size? –  or do they shrink? –  or stabilize?

Vertica'11

YES YES

YES

Page 65: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 65

Observation T.3: NLCC behavior •  After the gelling point, the GCC takes off, but

NLCC’s remain ~constant (actually, oscillate).

IMDB

CC size

Time-stamp Vertica'11

Page 66: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 66

Timing for Blogs

•  with Mary McGlohon (CMU->Google) •  Jure Leskovec (CMU->Stanford) •  Natalie Glance (now at Google) •  Mat Hurst (now at MSR) [SDM’07]

Vertica'11

Page 67: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 67

T.4 : popularity over time

Post popularity drops-off – exponentially?

lag: days after post

# in links

1 2 3

@t

@t + lag

Vertica'11

Page 68: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 68

T.4 : popularity over time

Post popularity drops-off – exponentially? POWER LAW! Exponent?

# in links (log)

days after post (log)

Vertica'11

Page 69: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 69

T.4 : popularity over time

Post popularity drops-off – exponentially? POWER LAW! Exponent? -1.6 •  close to -1.5: Barabasi’s stack model •  and like the zero-crossings of a random walk

# in links (log) -1.6

days after post (log)

Vertica'11

Page 70: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Vertica'11 C. Faloutsos (CMU) 70

-1.5 slope J. G. Oliveira & A.-L. Barabási Human Dynamics: The

Correspondence Patterns of Darwin and Einstein. Nature 437, 1251 (2005) . [PDF]

Page 71: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

T.5: duration of phonecalls Surprising Patterns for the Call

Duration Distribution of Mobile Phone Users

Pedro O. S. Vaz de Melo, Leman Akoglu, Christos Faloutsos, Antonio A. F. Loureiro

PKDD 2010 Vertica'11 C. Faloutsos (CMU) 71

Page 72: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Probably, power law (?)

Vertica'11 C. Faloutsos (CMU) 72

??

Page 73: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

No Power Law!

Vertica'11 C. Faloutsos (CMU) 73

Page 74: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

‘TLaC: Lazy Contractor’ •  The longer a task (phonecall) has taken, •  The even longer it will take

Vertica'11 C. Faloutsos (CMU) 74

Odds ratio=

Casualties(<x): Survivors(>=x)

== power law

Page 75: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

75

Data Description

  Data from a private mobile operator of a large city   4 months of data   3.1 million users   more than 1 billion phone records

  Over 96% of ‘talkative’ users obeyed a TLAC distribution (‘talkative’: >30 calls)

Vertica'11 C. Faloutsos (CMU)

Page 76: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 76

Outline

•  Introduction – Motivation •  Problem#1: Patterns in graphs •  Problem#2: Tools

– OddBall (anomaly detection) – Belief Propagation –  Immunization

•  Problem#3: Scalability •  Conclusions

Vertica'11

Page 77: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

OddBall: Spotting Anomalies in Weighted Graphs

Leman Akoglu, Mary McGlohon, Christos Faloutsos

Carnegie Mellon University School of Computer Science

PAKDD 2010, Hyderabad, India

Page 78: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Main idea For each node, •  extract ‘ego-net’ (=1-step-away neighbors) •  Extract features (#edges, total weight, etc

etc) •  Compare with the rest of the population

C. Faloutsos (CMU) 78 Vertica'11

Page 79: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS What is an egonet?

ego

79

egonet

C. Faloutsos (CMU) Vertica'11

Page 80: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Selected Features   Ni: number of neighbors (degree) of ego i   Ei: number of edges in egonet i   Wi: total weight of egonet i   λw,i: principal eigenvalue of the weighted

adjacency matrix of egonet I

80 C. Faloutsos (CMU) Vertica'11

Page 81: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS Near-Clique/Star

81 Vertica'11 C. Faloutsos (CMU)

Page 82: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS Near-Clique/Star

82 C. Faloutsos (CMU) Vertica'11

Page 83: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS Near-Clique/Star

83 C. Faloutsos (CMU) Vertica'11

Page 84: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Andrew Lewis (director)

Near-Clique/Star

84 C. Faloutsos (CMU) Vertica'11

Page 85: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 85

Outline

•  Introduction – Motivation •  Problem#1: Patterns in graphs •  Problem#2: Tools

– OddBall (anomaly detection) – Belief Propagation –  Immunization

•  Problem#3: Scalability •  Conclusions

Vertica'11

Page 86: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Vertica'11 C. Faloutsos (CMU) 86

E-bay Fraud detection

w/ Polo Chau & Shashank Pandit, CMU [www’07]

Page 87: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Vertica'11 C. Faloutsos (CMU) 87

E-bay Fraud detection

Page 88: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Vertica'11 C. Faloutsos (CMU) 88

E-bay Fraud detection

Page 89: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Vertica'11 C. Faloutsos (CMU) 89

E-bay Fraud detection - NetProbe

Page 90: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Popular press

And less desirable attention: •  E-mail from ‘Belgium police’ (‘copy of

your code?’) Vertica'11 C. Faloutsos (CMU) 90

Page 91: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 91

Outline

•  Introduction – Motivation •  Problem#1: Patterns in graphs •  Problem#2: Tools

– OddBall (anomaly detection) – Belief propagation –  Immunization

•  Problem#3: Scalability -PEGASUS •  Conclusions

Vertica'11

Page 92: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS Immunization and epidemic

thresholds •  Q1: which nodes to immunize? •  Q2: will a virus vanish, or will it create an

epidemic?

Vertica'11 C. Faloutsos (CMU) 92

Page 93: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Q1: Immunization: • Given

• a network, • k vaccines, and • the virus details

• Which nodes to immunize?

Vertica'11 93 C. Faloutsos (CMU)

Page 94: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Q1: Immunization: • Given

• a network, • k vaccines, and • the virus details

• Which nodes to immunize?

Vertica'11 94 C. Faloutsos (CMU)

Page 95: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Q1: Immunization: • Given

• a network, • k vaccines, and • the virus details

• Which nodes to immunize?

Vertica'11 95 C. Faloutsos (CMU)

Page 96: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Q1: Immunization: • Given

• a network, • k vaccines, and • the virus details

• Which nodes to immunize?

A: immunize the ones that maximally raise the `epidemic threshold’ [Tong+, ICDM’10]

Vertica'11 96 C. Faloutsos (CMU)

Page 97: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Q2: will a virus take over? •  Flu-like virus (no immunity, ‘SIS’) •  Mumps (life-time immunity, ‘SIR’) •  Pertussis (finite-length immunity, ‘SIRS’)

Vertica'11 C. Faloutsos (CMU) 97

β: attack prob δ: heal prob

Page 98: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Q2: will a virus take over? •  Flu-like virus (no immunity, ‘SIS’) •  Mumps (life-time immunity, ‘SIR’) •  Pertussis (finite-length immunity, ‘SIRS’)

Vertica'11 C. Faloutsos (CMU) 98

β: attack prob δ: heal prob

Α: depends on connectivity (avg degree? Max degree? variance? Something else?

Page 99: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Vertica'11 C. Faloutsos (CMU) 99

Epidemic threshold τ

What should τ depend on? •  avg. degree? and/or highest degree? •  and/or variance of degree? •  and/or third moment of degree? •  and/or diameter?

Page 100: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Vertica'11 C. Faloutsos (CMU) 100

Epidemic threshold

•  [Theorem] We have no epidemic, if

β/δ <τ = 1/ λ1,A

Page 101: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Vertica'11 C. Faloutsos (CMU) 101

Epidemic threshold

•  [Theorem] We have no epidemic, if

β/δ <τ = 1/ λ1,A

largest eigenvalue of adj. matrix A

attack prob.

recovery prob. epidemic threshold

Proof: [Wang+03] (for SIS=flu only)

Page 102: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

A2: will a virus take over? •  For all typical virus propagation models (flu,

mumps, pertussis, HIV, etc) •  The only connectivity measure that matters, is

1/λ1 the first eigenvalue of the adj. matrix [Prakash+, ‘10, arxiv]

Vertica'11 C. Faloutsos (CMU) 102

Page 103: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

A2: will a virus take over?

Vertica'11 C. Faloutsos (CMU) 103

Fraction of infected

Time ticks

Below: exp. extinction

Above: take-over

Graph: Portland, OR 31M links 1.5M nodes

Page 104: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 104

Outline

•  Introduction – Motivation •  Problem#1: Patterns in graphs •  Problem#2: Tools

– OddBall (anomaly detection) – Belief propagation –  Immunization

•  Problem#3: Scalability -PEGASUS •  Conclusions

Vertica'11

Page 105: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Vertica'11 C. Faloutsos (CMU) 105

Scalability •  Google: > 450,000 processors in clusters of ~2000

processors each [Barroso, Dean, Hölzle, “Web Search for a Planet: The Google Cluster Architecture” IEEE Micro 2003]

•  Yahoo: 5Pb of data [Fayyad, KDD’07] •  Problem: machine failures, on a daily basis •  How to parallelize data mining tasks, then? •  A: map/reduce – hadoop (open-source clone)

http://hadoop.apache.org/

Page 106: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 106

Centralized Hadoop/PEGASUS

Degree Distr. old old

Pagerank old old

Diameter/ANF old HERE

Conn. Comp old HERE

Triangles done HERE

Visualization started

Outline – Algorithms & results

Vertica'11

Page 107: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

HADI for diameter estimation •  Radius Plots for Mining Tera-byte Scale

Graphs U Kang, Charalampos Tsourakakis, Ana Paula Appel, Christos Faloutsos, Jure Leskovec, SDM’10

•  Naively: diameter needs O(N**2) space and up to O(N**3) time – prohibitive (N~1B)

•  Our HADI: linear on E (~10B) – Near-linear scalability wrt # machines – Several optimizations -> 5x faster

C. Faloutsos (CMU) 107 Vertica'11

Page 108: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

????

19+ [Barabasi+]

108 C. Faloutsos (CMU)

Radius

Count

Vertica'11

~1999, ~1M nodes

Page 109: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

YahooWeb graph (120Gb, 1.4B nodes, 6.6 B edges) •  Largest publicly available graph ever studied.

????

19+ [Barabasi+]

109 C. Faloutsos (CMU)

Radius

Count

Vertica'11

??

~1999, ~1M nodes

Page 110: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

YahooWeb graph (120Gb, 1.4B nodes, 6.6 B edges) •  Largest publicly available graph ever studied.

????

19+? [Barabasi+]

110 C. Faloutsos (CMU)

Radius

Count

Vertica'11

14 (dir.) ~7 (undir.)

Page 111: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

YahooWeb graph (120Gb, 1.4B nodes, 6.6 B edges) • 7 degrees of separation (!) • Diameter: shrunk

????

19+? [Barabasi+]

111 C. Faloutsos (CMU)

Radius

Count

Vertica'11

14 (dir.) ~7 (undir.)

Page 112: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

YahooWeb graph (120Gb, 1.4B nodes, 6.6 B edges) Q: Shape?

????

112 C. Faloutsos (CMU)

Radius

Count

Vertica'11

~7 (undir.)

Page 113: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

113 C. Faloutsos (CMU)

YahooWeb graph (120Gb, 1.4B nodes, 6.6 B edges) •  effective diameter: surprisingly small. •  Multi-modality (?!)

Vertica'11

Page 114: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Radius Plot of GCC of YahooWeb.

114 C. Faloutsos (CMU) Vertica'11

Page 115: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

115 C. Faloutsos (CMU)

YahooWeb graph (120Gb, 1.4B nodes, 6.6 B edges) •  effective diameter: surprisingly small. •  Multi-modality: probably mixture of cores .

Vertica'11

Page 116: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

116 C. Faloutsos (CMU)

YahooWeb graph (120Gb, 1.4B nodes, 6.6 B edges) •  effective diameter: surprisingly small. •  Multi-modality: probably mixture of cores .

Vertica'11

EN

~7

Conjecture: DE

BR

Page 117: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

117 C. Faloutsos (CMU)

YahooWeb graph (120Gb, 1.4B nodes, 6.6 B edges) •  effective diameter: surprisingly small. •  Multi-modality: probably mixture of cores .

Vertica'11

~7

Conjecture:

Page 118: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

Running time - Kronecker and Erdos-Renyi Graphs with billions edges.

details

Page 119: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 119

Centralized Hadoop/PEGASUS

Degree Distr. old old

Pagerank old old

Diameter/ANF old HERE

Conn. Comp old HERE

Triangles HERE

Visualization started

Outline – Algorithms & results

Vertica'11

Page 120: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS Generalized Iterated Matrix

Vector Multiplication (GIMV)

C. Faloutsos (CMU) 120

PEGASUS: A Peta-Scale Graph Mining System - Implementation and Observations. U Kang, Charalampos E. Tsourakakis, and Christos Faloutsos. (ICDM) 2009, Miami, Florida, USA. Best Application Paper (runner-up).

Vertica'11

Page 121: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS Generalized Iterated Matrix

Vector Multiplication (GIMV)

C. Faloutsos (CMU) 121

•  PageRank •  proximity (RWR) •  Diameter •  Connected components •  (eigenvectors, •  Belief Prop. •  … )

Matrix – vector Multiplication

(iterated)

Vertica'11

details

Page 122: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

122

Example: GIM-V At Work •  Connected Components – 4 observations:

Size

Count

C. Faloutsos (CMU) Vertica'11

Page 123: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

123

Example: GIM-V At Work •  Connected Components

Size

Count

C. Faloutsos (CMU) Vertica'11

1) 10K x larger than next

Page 124: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

124

Example: GIM-V At Work •  Connected Components

Size

Count

C. Faloutsos (CMU) Vertica'11

2) ~0.7B singleton nodes

Page 125: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

125

Example: GIM-V At Work •  Connected Components

Size

Count

C. Faloutsos (CMU) Vertica'11

3) SLOPE!

Page 126: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

126

Example: GIM-V At Work •  Connected Components

Size

Count 300-size

cmpt X 500. Why? 1100-size cmpt

X 65. Why?

C. Faloutsos (CMU) Vertica'11

4) Spikes!

Page 127: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

127

Example: GIM-V At Work •  Connected Components

Size

Count

suspicious financial-advice sites

(not existing now)

C. Faloutsos (CMU) Vertica'11

Page 128: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

128

GIM-V At Work •  Connected Components over Time •  LinkedIn: 7.5M nodes and 58M edges

Stable tail slope after the gelling point

C. Faloutsos (CMU) Vertica'11

Page 129: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 129

Outline

•  Introduction – Motivation •  Problem#1: Patterns in graphs •  Problem#2: Tools •  Problem#3: Scalability •  Conclusions

Vertica'11

Page 130: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 130

OVERALL CONCLUSIONS – low level:

•  Several new patterns (fortification, triangle-laws, conn. components, etc)

•  New tools: –  anomaly detection (OddBall), belief

propagation, immunization

•  Scalability: PEGASUS / hadoop

Vertica'11

Page 131: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 131

OVERALL CONCLUSIONS – high level

•  BIG DATA: Large datasets reveal patterns/outliers that are invisible otherwise

Vertica'11

Page 132: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 132

References •  Leman Akoglu, Christos Faloutsos: RTG: A Recursive

Realistic Graph Generator Using Random Typing. ECML/PKDD (1) 2009: 13-28

•  Deepayan Chakrabarti, Christos Faloutsos: Graph mining: Laws, generators, and algorithms. ACM Comput. Surv. 38(1): (2006)

Vertica'11

Page 133: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 133

References •  Deepayan Chakrabarti, Yang Wang, Chenxi Wang,

Jure Leskovec, Christos Faloutsos: Epidemic thresholds in real networks. ACM Trans. Inf. Syst. Secur. 10(4): (2008)

•  Deepayan Chakrabarti, Jure Leskovec, Christos Faloutsos, Samuel Madden, Carlos Guestrin, Michalis Faloutsos: Information Survival Threshold in Sensor and P2P Networks. INFOCOM 2007: 1316-1324

Vertica'11

Page 134: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 134

References •  Christos Faloutsos, Tamara G. Kolda, Jimeng Sun:

Mining large graphs and streams using matrix and tensor tools. Tutorial, SIGMOD Conference 2007: 1174

Vertica'11

Page 135: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 135

References •  T. G. Kolda and J. Sun. Scalable Tensor

Decompositions for Multi-aspect Data Mining. In: ICDM 2008, pp. 363-372, December 2008.

Vertica'11

Page 136: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 136

References •  Jure Leskovec, Jon Kleinberg and Christos Faloutsos

Graphs over Time: Densification Laws, Shrinking Diameters and Possible Explanations, KDD 2005 (Best Research paper award).

•  Jure Leskovec, Deepayan Chakrabarti, Jon M. Kleinberg, Christos Faloutsos: Realistic, Mathematically Tractable Graph Generation and Evolution, Using Kronecker Multiplication. PKDD 2005: 133-145

Vertica'11

Page 137: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 137

References •  Jimeng Sun, Yinglian Xie, Hui Zhang, Christos

Faloutsos. Less is More: Compact Matrix Decomposition for Large Sparse Graphs, SDM, Minneapolis, Minnesota, Apr 2007.

•  Jimeng Sun, Spiros Papadimitriou, Philip S. Yu, and Christos Faloutsos, GraphScope: Parameter-free Mining of Large Time-evolving Graphs ACM SIGKDD Conference, San Jose, CA, August 2007

Vertica'11

Page 138: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

References •  Jimeng Sun, Dacheng Tao, Christos

Faloutsos: Beyond streams and graphs: dynamic tensor analysis. KDD 2006: 374-383

Vertica'11 C. Faloutsos (CMU) 138

Page 139: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 139

References •  Hanghang Tong, Christos Faloutsos, and

Jia-Yu Pan, Fast Random Walk with Restart and Its Applications, ICDM 2006, Hong Kong.

•  Hanghang Tong, Christos Faloutsos, Center-Piece Subgraphs: Problem Definition and Fast Solutions, KDD 2006, Philadelphia, PA

Vertica'11

Page 140: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 140

References •  Hanghang Tong, Christos Faloutsos, Brian

Gallagher, Tina Eliassi-Rad: Fast best-effort pattern matching in large attributed graphs. KDD 2007: 737-746

Vertica'11

Page 141: Large Graph Miningchristos/TALKS/11-Vertica/FOILS/... · 2011. 8. 7. · CMU SCS Large Graph Mining Christos Faloutsos CMU . CMU SCS Thank you! • Stephen Walkauskas Vertica'11 C

CMU SCS

C. Faloutsos (CMU) 141

Project info

Akoglu, Leman

Chau, Polo

Kang, U McGlohon, Mary

Tong, Hanghang

Prakash, Aditya

Vertica'11

Thanks to: NSF IIS-0705359, IIS-0534205, CTA-INARC; Yahoo (M45), LLNL, IBM, SPRINT, Google, INTEL, HP, iLab

www.cs.cmu.edu/~pegasus

Out, next year

Koutra, Danae