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Bitcoin => Bitcoin Discussion => Topic started by: Wilikon on May 07, 2013, 03:52:14 AM



Title: BitTorrent Sync - An inspiration for the blockchain?
Post by: Wilikon on May 07, 2013, 03:52:14 AM
I did not say "a solution" but an inspiration for the blockchain distribution speed?


http://labs.bittorrent.com/experiments/sync.html?utm_source=BitTorrentBlog&utm_medium=Post&utm_campaign=Sync_050613

http://youtu.be/KGnh7Ep18do

Those with the technical know-how could maybe check this out. Or maybe it is nothing.


Title: Re: BitTorrent Sync - An inspiration for the blockchain?
Post by: wumpus on May 07, 2013, 05:46:04 AM
My impression was that it's closed source and they don't document the protocol, so I lost my interest.


Title: Re: BitTorrent Sync - An inspiration for the blockchain?
Post by: Sukrim on May 07, 2013, 07:15:33 AM
Also the initial block chain bootstrap process is usually NOT limited by download speed but by CPU speed to verify the transactions. There's also already a well seeded torrent file with all block up to a certain height (the latest checkpoint that's compiled in anyways) to speed up downloading even more.


Title: Re: BitTorrent Sync - An inspiration for the blockchain?
Post by: mc_lovin on May 07, 2013, 07:20:57 AM
The solution is going to be in distributed blockchain storage, not distribution.  Somehow where we can have maxcopies=10000 and have everyone store a tiny bit of the chain, sort of like a big RAID-5 with tons of copies out there, but it doesn't become an epidemic where there are 1 million people with 1TB hdds full of transactions.. if we all had a tiny part of it, then it could grow to the petabytes.


Title: Re: BitTorrent Sync - An inspiration for the blockchain?
Post by: Sukrim on May 07, 2013, 12:59:44 PM
No, if I have to trust others to keep data for me, there are easier solutions again.
Also, it will take a long time still to reach 1 terabyte. Just pruning alone makes the utxo set shrink to below 1gb AFAIK.


Title: Re: BitTorrent Sync - An inspiration for the blockchain?
Post by: dave111223 on May 07, 2013, 01:26:50 PM
The solution is going to be in distributed blockchain storage, not distribution.  Somehow where we can have maxcopies=10000 and have everyone store a tiny bit of the chain, sort of like a big RAID-5 with tons of copies out there, but it doesn't become an epidemic where there are 1 million people with 1TB hdds full of transactions.. if we all had a tiny part of it, then it could grow to the petabytes.

I like the idea, but it would be difficult to know who is supposed to download which part of the chain.

For example with bittorrent you might have 1000s of people each with a little piece of the file, which as a whole add up to the entire file.  However each person in the swamp has a clean goal; download 100% of the file.  Everyone is working all the way to 100% (they may never get there but that's what they are working towards).

So if you weren't working towards 100%..then what percent would you be working towards?  Say you decide on 15%, how would you decide which 15% to download?  What if everyone decided to download the first 15%


Title: Re: BitTorrent Sync - An inspiration for the blockchain?
Post by: khal on May 07, 2013, 03:12:09 PM
The solution is going to be in distributed blockchain storage, not distribution.  Somehow where we can have maxcopies=10000 and have everyone store a tiny bit of the chain, sort of like a big RAID-5 with tons of copies out there, but it doesn't become an epidemic where there are 1 million people with 1TB hdds full of transactions.. if we all had a tiny part of it, then it could grow to the petabytes.

I like the idea, but it would be difficult to know who is supposed to download which part of the chain.

For example with bittorrent you might have 1000s of people each with a little piece of the file, which as a whole add up to the entire file.  However each person in the swamp has a clean goal; download 100% of the file.  Everyone is working all the way to 100% (they may never get there but that's what they are working towards).

So if you weren't working towards 100%..then what percent would you be working towards?  Say you decide on 15%, how would you decide which 15% to download?  What if everyone decided to download the first 15%
This problem is trivial : randomly select 15 blocks among 100.
Each user starting the blockchain from 0 will have different blocks.
Random selection ensure you an equal distribution of blocks among all users.

The percent of blocks you must download should be related to the number of connections you have, to avoid asking blocks to your peers and nobody have it, so they must ask to their peers, etc.


Title: Re: BitTorrent Sync - An inspiration for the blockchain?
Post by: Wilikon on May 07, 2013, 04:48:10 PM
My impression was that it's closed source and they don't document the protocol, so I lost my interest.


Yes it is. I was not promoting the company and the code but more like a way to define the problems ahead with technical ideas around us now.


Title: Re: BitTorrent Sync - An inspiration for the blockchain?
Post by: TheKoziTwo on May 07, 2013, 05:05:41 PM
I've been running bittorrent sync for about a week and I love it! I doubt bittorrent sync would work out of the box though, it would require a centralized entity to push new blockchains for people to sync.