Simple Module Chord

File: Overlay/Chord/Chord.ned

C++ definition: click here

The main module of the Chord implementation

Author: Ingmar Baumgart, Markus Mauch

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OverlayChord

Implementation of the Chord KBR overlay as described in "Chord: A Scalable Peer-to-Peer Lookup Protocol for Inetnet Applications" by I. Stoica et al. published in Transactions on Networking.

Parameters:

Name Type Description
localPort numeric

UDP port for Chord messages

debugOutput bool

enable debug output

keyLength numeric

overlay key length in bits

measureNetwInitPhase bool

gather statistics when bootstrapping

useCommonAPIforward bool

enable CommonAPI forward() calls

drawOverlayTopology bool

draw arrow to successor node?

hopCountMax numeric

maximum number of overlay hops

joinOnApplicationRequest bool

only join the overlay on application request

lookupRedundantNodes numeric

number of next hops in each step

lookupParallelPaths numeric

number of parallel paths

lookupParallelRpcs numeric

number of nodes to ask in parallel

lookupSecure bool

true, if all nodes should be identified with a ping

lookupMerge bool

true, if parallel Rpc results should be merged

lookupFailedNodeRpcs bool

communicate failed nodes

useBaseLookup bool

use the base lookup class

iterativeLookup bool

do iterative instead of recursive lookups

successorListSize numeric

max number of successors in the SuccessorList

joinRetry numeric

after joinRetry unsuccessful join requests, we fetch a need bootstrap node from the BootstrapOracle

stabilizeRetry numeric

retries before a successor is considered failed

joinDelay numeric

delay between join retries (sec)

stabilizeDelay numeric

stabilize interval (sec)

fixfingersDelay numeric

fix_fingers interval (sec)

aggressiveJoinMode bool

use modified (faster) JOIN protocol

extendedFingerTable bool
numFingerCandidates numeric
proximityRouting bool

use proximity routing

Gates:

Name Direction Description
from_udp [ ] input

gate from the UDP layer

to_udp [ ] output

gate to the UDP layer

from_app input

gate from the application

to_app output

gate to the application

Source code:

simple Chord

    parameters:
        localPort : numeric,         // UDP port for Chord messages
        debugOutput : bool,          // enable debug output
        keyLength : numeric,         // overlay key length in bits
        measureNetwInitPhase: bool,  // gather statistics when bootstrapping
	useCommonAPIforward : bool,  // enable CommonAPI forward() calls
        drawOverlayTopology : bool,  // draw arrow to successor node?
        hopCountMax : numeric,       // maximum number of overlay hops
	joinOnApplicationRequest : bool, // only join the overlay on application request

	lookupRedundantNodes : numeric, // number of next hops in each step
	lookupParallelPaths : numeric,  // number of parallel paths
	lookupParallelRpcs : numeric,   // number of nodes to ask in parallel
	lookupSecure : bool, // true, if all nodes should be identified with a ping
	lookupMerge : bool, // true, if parallel Rpc results should be merged
	lookupFailedNodeRpcs : bool, // communicate failed nodes


	useBaseLookup : bool,	  // use the base lookup class
        iterativeLookup : bool,   // do iterative instead of recursive lookups

	// max number of successors in the SuccessorList
        successorListSize : numeric,

        // after joinRetry unsuccessful join requests, we fetch
        // a need bootstrap node from the BootstrapOracle
        joinRetry : numeric,         

	// retries before a successor is considered failed
        stabilizeRetry : numeric, 
        
	joinDelay : numeric,            // delay between join retries (sec)
        stabilizeDelay : numeric,       // stabilize interval (sec)
        fixfingersDelay : numeric,      // fix_fingers interval (sec)
        aggressiveJoinMode : bool,      // use modified (faster) JOIN protocol
	extendedFingerTable : bool,
    	numFingerCandidates : numeric,
	proximityRouting : bool;	// use proximity routing

    gates:
        in: from_udp[];	// gate from the UDP layer
        out: to_udp[];    // gate to the UDP layer
        in: from_app;   // gate from the application
        out: to_app;	// gate to the application

endsimple