Bitcoin Forum

Bitcoin => Development & Technical Discussion => Topic started by: johnyh on January 16, 2011, 11:17:37 AM



Title: Overtaking the network - like tesnet
Post by: johnyh on January 16, 2011, 11:17:37 AM
Testnet is broken because too much power was puten there (thanks Xelister 1 and Artfortz 8 of 5970's ;)

It will take apparently months (with 1 5970) to reset diff to be usable by CPUs.

Is this design flaw? I think so.

Solution: lower diff also each say 72 hours passing with too few (or none!) blocks.

Also disallow overtaking network and forcing switch to own version of chain - with like totally other history for last 1 week, or 1 month, or even since the begining!
Solution: use more anchors (e.g. fixed points in chain on which everyone agrees).
Not only in source code but also distribute them. Say each 2 days?


Title: Re: Overtaking the network - like tesnet
Post by: FreeMoney on January 16, 2011, 12:12:31 PM
Testnet is broken because too much power was puten there (thanks Xelister 1 and Artfortz 8 of 5970's ;)

It will take apparently months (with 1 5970) to reset diff to be usable by CPUs.
 

Haha, is this why nanotube and others were offering to buy testnet coins on bitcoin-otc? I guess that would make the adjustment faster, but less severe?


Title: Re: Overtaking the network - like tesnet
Post by: Gavin Andresen on January 16, 2011, 03:23:17 PM
Adjusting the testnet difficulty every, oh, say 100 blocks (instead of 2016) seems like a good idea to me.

That's a trivial patch; I nominate ArtForz and Xelister to write it and submit a pull request.

Locking in the testnet block chain-- not so much.  I don't think it is worth the effort to either come up with a mechanism for distributing the lock-in points or manually put lock-in points in the source code.


Title: Re: Overtaking the network - like tesnet
Post by: theymos on January 16, 2011, 03:52:55 PM
Changing the testnet target time per block to 5 minutes and removing subsidy adjustments would also be nice.


Title: Re: Overtaking the network - like tesnet
Post by: Cdecker on January 16, 2011, 04:59:43 PM
Changing the testnet target time per block to 5 minutes and removing subsidy adjustments would also be nice.
Why do I feel that at some point we'll drop the main network and stick with the test network :D


Title: Re: Overtaking the network - like tesnet
Post by: Anonymous on January 17, 2011, 02:25:58 AM
Adjusting the testnet difficulty every, oh, say 100 blocks (instead of 2016) seems like a good idea to me.

That's a trivial patch; I nominate ArtForz and Xelister to write it and submit a pull request.

Locking in the testnet block chain-- not so much.  I don't think it is worth the effort to either come up with a mechanism for distributing the lock-in points or manually put lock-in points in the source code.


Seems fair....they caused the generation difficulty lol.

Is that akin to sending them to the naughty chair?


Title: Re: Overtaking the network - like tesnet
Post by: tcatm on January 17, 2011, 02:37:08 AM
Testnet can be reset within 2 days by overtaking the blockchain. This will reset all balances. I might actually do that this week. Final difficulty will be ~ 0.5 after reset.


Title: Re: Overtaking the network - like tesnet
Post by: j16sdiz on January 17, 2011, 03:50:13 AM
I think taking over testnet is a feature, not a bug. This allow you do some code testing on the whole network.


Title: Re: Overtaking the network - like tesnet
Post by: gigitrix on January 25, 2011, 07:20:48 PM
It's a bug in test net because no-one (comparatively) was using it.

It's impossible in live, because by the time governments care and devote their super-secret NSA SHA-256 bruteforce clusters, they still won't make that much of a dent :D


Title: Re: Overtaking the network - like tesnet
Post by: theymos on January 25, 2011, 08:26:12 PM
Sure the first 10-15,000 blocks will go fast even less than a day, but how would you overtake the testnet in just two days with those difficulty levels?

The new chain will consist of fewer blocks, but it will represent more work (difficulty per block), so Bitcoin will consider it "longer".

Was the 4x rule, considered, though? That might slow things down somewhat.


Title: Re: Overtaking the network - like tesnet
Post by: tcatm on January 26, 2011, 12:56:00 AM
4x rule was considered and actually makes overtaking easier. You can create 5 (iirc) blocks per second (implicit limit in AcceptBlock()). Without the 4x rule difficulty would rise to too high after the first 2016 blocks. With the rule, it will rise to 4 and we can still generate the next 2016 blocks in a short time.