Re: Distributed file system using routing inspired by Freenet

Michael Rogers wrote:

> Matthew Toseland wrote:
>> We then multiply that by two from splitfile redundancy, to get a total
>> redundancy of 6. Wuala works well with a factor of 5 redundancy... but
>> that's entirely due to FEC.
> 
> Two FEC blocks each replicated three times aren't really comparable to
> five FEC blocks, are they? You can't use any combination of them to
> recover the data.
> 
>> They simulated ordinary redundancy and needed a factor
>> of 24 to be reliable, but a factor of 5 for FEC.
> 
> I'm not convinced their churn model is realistic - they assume that the
> nodes' uptimes are independent, but studies of Gnutella and Skype show
> strong daily and weekly cycles - if each node is online 25% of the time
> it doesn't follow that 25% of the nodes are online at any given time.

I have observed this first hand in a crawler I implemented long ago for the
Shareaza network. See, for example, here:

http://crawler.trillinux.org/history.html

(I'm no longer maintaining these pages, BTW. Somebody took over circa 2005.)