[p2p-hackers] Sloppy Chord

Kevin Atkinson kevin at atkinson.dhs.org
Mon Mar 31 07:18:01 UTC 2003


On Mon, 31 Mar 2003, Zooko wrote:

>  Kevin Atkinson <kevin at atkinson.dhs.org> writes:
> >
> > What advantages does Chord[1] offer over Pastry[2]?  I chose Pastry over
> > chord because of it simplicity, and the because of the so called "free
> > choice" property.
> 
> Heh heh.  Simplicity is funny.  I believe that Brandon Wiley prefers
> Chord over Pastry because of its simplicity.  ;-)

Well I guess it is how you look at it.  I thought Pastry was simpler
than Chord, at least the idea.  My implementation of Pastry makes several 
simplifications:
  1) No Neighborhood set.
  2) No "real" leaf set.  Instead any row which does not have at least one
     node in each entry is a leaf row.
  3) Distance is strictly bitwise not numerical.  (bitwise meaning the 
     number of common bits.  Ie 1101 and 1111 would have a distance of 2)

2 and 3 mean that all nodes in the "leaf set" have identical leaf sets.  
which simplifies the implementation.

> I prefer Pastry-or-Kademlia over Chord because of the free choice and, to a 
> lesser extent, because of the symmetric metric.
> 
> I prefer Kademlia over Pastry because of the simplicity of exposition and 
> argument in the original Kademlia paper.  Also Kademlia has a simplification 
> over Pastry (no "leaf sets"), but I suspect that this simplification might come 
> with a cost in reduced robustness.

I will have to look at Kademlia.  It may be very similar to what I did 
with Pastry.

> > In fact my network DistribNet[3], is essentially implementing the ideas of
> > Coral[4] but on top of Pastry rather than chord.
> 
> Wow!  I need to read about Coral now.  I haven't read the iptps03 proceedings 
> yet, so I am obviously behind the times now.

Well I have not herd of Kademlia or Coral until yesterday :-|.

--- 
http://kevin.atkinson.dhs.org





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