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Scalable Resource Information Service for Computational Grids Nian-Feng Tzeng Center for Advanced Computer Studies University of Louisiana at Lafayette December 7, 2007

December 7, 2007

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Scalable Resource Information Service for Computational Grids Nian-Feng Tzeng Center for Advanced Computer Studies University of Louisiana at Lafayette. December 7, 2007. Computational Grids. Comp. Grid. Grid Resource Information Service. Computational Grid. Grid Resource Information Service. - PowerPoint PPT Presentation

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Page 1: December 7, 2007

Scalable Resource Information Servicefor Computational Grids

Nian-Feng TzengCenter for Advanced Computer Studies

University of Louisiana at Lafayette

December 7, 2007

Page 2: December 7, 2007

Computational Grids

Com

p.

Grid

Page 3: December 7, 2007

Grid Resource Information Service

Computational Grid

Page 4: December 7, 2007

Core GIIS

Core Grid

Grid Resource Information Service

Page 5: December 7, 2007

Under GRAM reporter of GT: – at least, one system-wide GIIS – each resource provider (e.g., cluster header) runs GRIS

to provide queuing information and others

Grid Resource Information Service

Page 6: December 7, 2007

Typical MDS-4 deployment

Page 7: December 7, 2007
Page 8: December 7, 2007

What is P2P?

• A distributed system architecture:• No centralized control• Nodes are symmetric in function

• Typically many nodes, but unreliable and heterogeneous

Client

Client

Client Client

Client

Internet

Page 9: December 7, 2007

Example P2P problem: lookup

Internet

N1

N2 N3

N6N5

N4

Publisher

Key=“title”Value=file data… Client

Lookup(“title”)

?

• publish/lookup at the heart of all P2P systems

Page 10: December 7, 2007

Another approach: distributed hash tables

(DHTs)

• Nodes are the hash buckets• Key identifies data uniquely• DHT balances keys and data across nodes• DHT replicates, caches, routes lookups, etc.

Distributed hash tables

Distributed applications

Lookup (key) data

node node node….

Insert(key, data)

Page 11: December 7, 2007

Chord lookups

• Map keys to nodes in a load-balanced way• Hash a node IP addr. into a long string of digit

(node ID)• Hash a key to the same string length (key ID)• Assign hashed key to “closest” node (i.e., its

successor)• Refer hashed node ID & key ID, as ID & key,

respectively

K20K5

K80

CircularID space N32

N90

N105

N60

• Forward key lookup to a closer node• Insert: lookup + store

• Join: insert node in ring

Page 12: December 7, 2007

Chord’s routing table: fingers

N80

½¼

1/8

1/161/321/641/128

Page 13: December 7, 2007

Lookups take O(log(N)) hops

N32

N10

N5

N20

N110

N99

N80

N60

Lookup(K19)

K19

• Lookup: route to closest predecessor

Page 14: December 7, 2007

Figure. Finger tables at existing nodes 0, 1, 3, to specifysubsequent intervals and their corresponding successors.

Steps for Node 3 to find successor of key = 1: a. key = 1 belongs to 3.finger[3].interval b. Node 3 checks its 3rd finger entry, succ. = 0 c. Node 0 checks its 1st finger entry, gets its succ. = 1 (key is within the smallest possible interval, 1st entry answer = succ.)

3 keys existing, 1, 2, 6,held in different nodes

held

held

held

Page 15: December 7, 2007

Prefix Hash Trees (PHTs)

• Easy deployment using OpenDHT• 3 APIs – put, delete, get• Application – Place Lab

• Range queries• Multiple attributes – combined using

linearization• Hash on prefixes

• Beacon ID hashed to SHA-1

Page 16: December 7, 2007
Page 17: December 7, 2007

PHT search takes O(log(log(N))) hops

Page 18: December 7, 2007

Fast and Scalable Resource Discovery

Our Work by Denvil Smith

well IDnamebore

pressuretemp

user

attribute/querytranslation

DHT(Chord)

user notification

Well data

querywell ID = 2701

get hash

searchPHT until

findingleaf node

checknode

capacity

createleaf nodes

updatePHT

updateDHT

get hash

searchPHTover DHT

validateselection

internalnodes

findsuccessorsuntil getting

leaf nodeWell ID = 2701Name = geiserBore = 89.99

Pressure = 28.8Temp = 512

query lookupsresource publishing

Page 19: December 7, 2007

Our Work by Denvil Smith

Page 20: December 7, 2007

Our Work by Denvil Smith

Page 21: December 7, 2007

Questions?

Please Ask!