Memory of Master and Techniques of Tunis Realised by : Nesrine - - PowerPoint PPT Presentation

Higher School of Sciences and Techniques of Tunis

Nesrine KHOUZAMI Realised by :

Memory of Master

Introduction Implementations BonjourGrid Proposed approach Experimentations Conclusion and perspectives Problematic Existing approaches

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Introduction Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives

Desktop grids Goal

Collect many computers when they are inactive. Address scientific problems that require intensive computing capacity.

Examples

SETI@Home, ClimatePrediction@Home, XtremWeb, etc.

Architectures

Centralized, hybrid, decentralized.

Specifications

Volatility Dynamic environment Unreliability Failure of resources Heterogeneity Scalability Voluntary participation

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The problem of selfishness Definition

Exploit resources disposed by other peers without contributing its

• wn to the system.

Selfish Contributor Two types of peers:

Causes

Additional cost. No differentiation between selfish and contributor peers. Lack of incentives.

Impacts

Move towards the use of client/server paradigm etc. Affect the quality of service.

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

Introduction Implementations BonjourGrid Proposed approach Experimentations Conclusion and perspectives Problematic Existing approaches

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Use of resources by peers to the detriment of others Absence of mechanism for resource reservation in BonjourGrid Permanent occupation of resources notebly by selfish peers

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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Scenario 1

A B C D

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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A B C

Scenario 2

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

Implementations BonjourGrid Proposed approach Experimentations Conclusion and perspectives Problematic Existing approaches

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Introduction

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Micropayment approaches Definition

The exchange of resources requires a monetary transaction managed by a central authority. Online Offline Two modes of exchange :

Exemples

PPay, FairPeers, Karma, etc.

Disadvantages

Centralization. Persistent identifiers. etc.

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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Reciprocity approaches Definition

Prioritizing peers according to their quality of service provided based on historical behavior. Direct. Indirect. Two types of reciprocity:

Examples

BitTorrent, PSH.

Disadvantages

Sustainability of peers connections. Cost of peers searching.

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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Reputation appraoches Definition

The level of confidence in such a peer is proportional to its reputation score as a result of its previous interactions. Local. Global. Two types of reputation :

Properties and challenges

Calculation model

Examples

PeerTrust, EigenTrust, Gupta & al, NICE, H-Trust, XRep. Metric of reputation Type of reputation Fiability Local control Cost of communication Cost of storage Scalability

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

Implementations BonjourGrid Proposed approach Experimentations Conclusion and perspectives Problematic Existing approaches

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Introduction

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Goal

Reduce the factor of centralization. Benefit from the existing decentralized tools of resources discovery Build an execution environment in a decentralized, dynamic and autonomous manner. Create a computing element composed of a coordinator and participating machines.

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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Levels of BonjourGrid

User Level 1 Level 0

A B A B A B

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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Construction of computing element

A 1 2 N

Idle Idle Idle Coordinator

CPU frequency Type of processor Size of the volatile memory etc. IdleMachineDict MyWorkersDict Nbre N required

IdleService Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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A 1 2 N

Idle Idle Idle Coordinator

workerService

workerRequest

workerService workerService

worker worker worker MyConfirmation Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

Construction of computing element

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A 1 2 N

Coordinator

coordinatorService

worker worker worker

coordinatorService coordinatorService CE

A

Idle

1

Idle

2

Idle

N

Idle Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

Construction of computing element

Implementations BonjourGrid Proposed approach Experimentations Conclusion and perspectives Problematic Existing approaches

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Introduction

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Contribution

Privilege the most deserving peer and curb any selfish behavior Integration of a decentralized mechanism for resource reservation in BonjourGrid based

• n scores of peers

The score of a peer is related to its consumption and provision of resources

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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Adopted context

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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General overview

Evaluation

Provision of resources Resources reservation from the grid Consumption of resources

A

Resources reservation for the grid Score computing

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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The evaluation of a reservation

A B

Coordinator worker

texec = dateEndAlloc - dateStartAlloc Cost = texec * freqB Evaluation of cost

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The evaluation of a reservation

<?xml version="1.0" ?> <root> <value num = "1"> <cost> <costmin>0</costmin> <costmax>1000</costmax> </cost> <valueCP>5</valueCP> </value> <value num = "2"> <cost> <costmin>1000</costmin> <costmax>1500</costmax> </cost> <valueCP>10</valueCP> </value> <value num = "3"> <cost> <costmin>1500</costmin> <costmax>2000</costmax> </cost> <valueCP>15</valueCP> </value> </root> Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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Phase of score computing

A 1

ValueC1

n 2 1 2 n

ValueC2 ValueCn ValueP1 ValueP2 ValuePn scoreG = scoreP-scoreC

VectorC Providers VectorP Consumers

Allocate Allocate

scoreP scoreC

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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Phase of score computing

<?xml version="1.0" ?> <root> <hostname>graphene-1 </hostname> <reputationscore>250</reputationscore> <providers> <provider> <hostnamep>graphene-2</hostnamep> <ValueC>100</ValueC> </provider> <provider> <hostnamep>graphene-3</hostnamep> <ValueC>150</ValueC> </provider> </providers> <consumers> <consumer> <hostnamec>graphene-4</hostnamec> <ValueP>200</ValueP> </consumer> <consumer> <hostnamec>graphene-5</hostnamec> <ValueP>300</ValueP> </consumer> </consumers> </root> Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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The model of reservation

A B

scoreGA scoreGB scoreGB > scoreGA

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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The model of reservation

<?xml version="1.0" ?> <root> <value num = "1"> <score> <scoremin>-10</scoremin> <scoremax>0</scoremax> </score> <nbreMachineSure>3</nbreMachineSure> </value> <value num = "2"> <score> <scoremin>10</scoremin> <scoremax>20</scoremax> </score> <nbreMachineSure>4</nbreMachineSure> </value> <value num = "3"> <score> <scoremin>20</scoremin> <scoremax>30</scoremax> </score> <nbreMachineSure>5</nbreMachineSure> </value> </root> Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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The model of reservation

Connect to the system Submit application Reservation phase Start coordinator Search N idle machines

Machines found

Selection of machines Request for participation Search N machines working as workerBE

Machines found

Selection of machines Request for participation

Nbr confirmations == N initial

Launch the application Choose the coordinator with the lowest score Search for existing coordinators Ask the chosen coordinator to free resources

State coordinator

no yes N=N-Nbr found machines no yes N=N-Nbr found machines yes

N = N initial-Nbr confirmations

no

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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The model of reservation

Be declared as visible to all coordinators Reservation completed Stay tuned to a request to release resources Terminate execution with N machines initially reserved request discovered Terminate execution with N sure machines

yes yes no yes M=N reserved – N sure no no

N reserved machines > N sure machines scoreG < scoreNewCoord Inform M workers to change their status Machines withdrawn Terminate execution with N = N reserved – N withdrawn = M < M Ignore the request

yes no

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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The model of reservation

Start BonjourGrid Be declared as idle machine Discovery new coordinators requests

Coord x found

Treat the discovered request Stay tuned to the request

• f the coordinator to

change state

Request discovered

Change the state Attach to the new coordinator Discovery of new coordinators requests State Idle

non

• ui

State workerBE Start the worker State worker Keep the score of the coord causing the change of state Remain attached to the initial coord

NewCoord x found scoreNewC

• ord

> scoreToler- ated

Leave the initial coordinator scoreTolerated

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

Implementations BonjourGrid Proposed approach Experimentations Conclusion and perspectives Problematic Existing approaches

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Introduction

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master : published by any coordinator whose number of reserved machines exceeds the sure machines. nameCoord-masterBE : published by a coordinator who wants to withdraw resources of nameCoord having the lowest score. nameCoord-masterBE-nameWorker : notify the worker nameWorker to change his status to workerBE. workerBE : published by a worker who changed his status to workerBE. nameCoord-Quit : published by a worker when he left his initial coordinator.

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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A B C D

scoreGA Nbr of sure machines CE CE CE Idle Idle Idle Idle Coordinator N machines _idle._tcp Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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A B C D

CE CE CE _workerBE._tcp Coordinator N machines = Nbre initial

• Nbre reserved

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A B D

_master._tcp N machines = Nbr initial

• Nbr reserved

scoreGA scoreGB scoreGD _B-masterBE._tcp NbrToLiberate = NbrReserved

• NbrSure

_master._tcp _master._tcp Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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A B

Coordinator _B-masterBE._tcp

E F G

_B-masterBE-F._tcp _B-masterBE-G._tcp

_B-masterBE-E._tcp _B-masterBE-F._tcp _B-masterBE-G._tcp

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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A B

Coordinator _B-masterBE._tcp

E F G

_workerBE._tcp _workerBE._tcp

scoreTolerated = scoreGA

H

scoreTolerated % scoreGH scoreGH scoreGA _master._tcp Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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A B

Coordinator _B-masterBE._tcp

E F G

_F._tcp _G._tcp _F._tcp _G._tcp _B-Quit._tcp _B-Quit._tcp

_B-Quit._tcp Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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A

Coordinator N requested = N reserved

F G

CE

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

Implementations BonjourGrid Proposed approach Experimentations Conclusion and perspectives Problematic Existing approaches

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Introduction

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Scenario 1

Arrival time = 0s Reservation duration = 3600 Available Nbr= 47 Requested Nbr = 24 Reserved Nbr = 24

Graphene-21

Arrival time = 0s Reservation duration = 3600 Available Nbr = 47 Requested Nbr = 23 Reserved Nbr = 23

Graphene-22

Arrival time = 60s Reservation duration = 2500 Available Nbr = 0 Requested Nbr = 15 Reserved Nbr = 0

Graphene-23

Resources reservation is random, it does not undergo any constraint of time or number.

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Scenario 2

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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Scenario 2

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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Scenario 3

The score is the only factor determining the number

• f machines

that a node can keep.

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Scenario 4

Even the arrival of a node that has the highest score and demands a number of machines greater than the available

• ne, it can

not remove the other sure machines.

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

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Scenario 5

If a node has a higher score, it is always safe and terminates its execution without any disturbance coming from less deserving nodes.

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

Implementations BonjourGrid Proposed approach Experimentations Conclusion and perspectives Problematic Existing approaches

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Introduction

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Conclusion

Study of selfishness problem and incentive approaches dealing with it. Proposal of a decentralized approach for resources reservation in BonjourGrid based on the score metric. Evaluation of the proposed solution through experiments showing that the resources reservation is more codified.

Perspectives

Evolution of the formula of score calculation. Realization of more advanced experiments. Integration of the security aspect.

Problematic Existing approaches BonjourGrid Proposed approach Implementations Experimentations Conclusion and perspectives Introduction

Thank you

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