incentive mechanismas a solution of the free riding problem

Design Document of P2P simulator19971241 김종욱

content

design requirement simulator

initialization simulation simulation end peer protocol network

Design requirement

easy to change protocol

ex) Chord and others peer action model

ex) with free riding mechanism, or not network topology

Simulator

Peer

P2P Protocol

Network

Peer

P2P Protocol

Peer

P2P Protocol......

Topology

EventTimer

•global

Simulator

P2PSystem

Initialization

simulator

network peer factory

peer

protocol

job queue

1

2

3

4

5

topology

6

chord

Simulation

PeerProtocol

query

Networksend(src, trg, packet)

jobqueue

workerthread

dequeue

queue( job, delay )

simulator

start

receivereturn result

joinleave

topology

latency

Simulation end

condition all peers leave the system there's no shared thing in the system

Event Thread

Event Object attribute

who label to execute args time to execute

interface void doAction( label, args )

using time priorty queue simplely run who.doAction( label, args )

EventTimer EventQueue

EventThread

schedule( Event e, delay ) queue( Event e, delay )

schedule( Event e )

dequeue()

delay = 0

- time priority queue- time 이 같다면 먼저 들어온 event 가 우선순위를 가진다 .

getCurrentTime()

- simulation 의 현재 시간

Event Thread

dequeue

current <request time

update current time

yes

do job()

Peer

start

if enough

makeToBDownload List

increasewaitCntr

if waitCntr> Threshold

No

Leave the system

wait random times

choose a fileto download

download

wait for random times

SimplePeerModel without free riding control mechanism

SimplePeer( Detail )

Peer

Protocol

Global File List

Shared File List

Downloaded File List

To Be DownloadList

querydownload

WaitCntr and ETC

network

node(nid) node(nid) node(nid)......

protocol protocol protocol

peer peer peer

topology

eventtimer

p2psystem

initialization

simulator P2P system peerprotocolnetworktopology

initinit

init

init with peer info

joinjoin

start

peerfactory

init

create peers

init

SimplePeer(flow)

Peer P2PSystem Protocol

get global file list

return

make a list to be download

if not enoughWaitCntr++& retry

select a file

request download

location return

download complete

sleep for a while

query

get file location

return file location

Protocolon another

Network

send

generate receive event

send dummy datareceive data event

leave

leave

Peer Protocol Network

query( callee, what )

query_result : query, pid list

download( callee, filename, pid )

send( src nid, trg nid, download request )

receive( src nid, download complete )

Protocol

receive( src nid, download request )

senddummy( src nid, trg nid, size )

download complete event: filename

P2P system global variable

File

FID Size

peer

sharedFileList

sharingpeerlist

PID

USER P2P application

join

leave

query

download

P2P Protocol

Protocol

SimpleProtocol query

always successful searching

Chord

Network

SimpleNetwork the latency between peers is zero bandwidth : constant k

implement others on demand

network

topology

latency(src,trg) bandwidth

protocol

send(src,trg, packet)