[1500 TH] p2pool: Decentralized, DoS-resistant, Hop-Proof pool

[DeathAndTaxes]

The transition ~40 hours ago went better than expected. Thanks to all for upgrading.

Now that we're using the new implementation, miners can volunteer to raise their share difficulty by adding something like "/1300" to the end of their miners' usernames. The 1300 is the difficulty of your own shares, and can be changed but must be higher than P2Pool's difficulty (currently 650) to have any effect. I urge anyone whose variance is dominated by P2Pool's block finding to try this (which really means anyone who gets more than a few shares per hour). This has the effect of lowering P2Pool's difficulty for the benefit of small miners, which may let P2Pool grow further.

Last, a side note (mainly to DeathAndTaxes): I just pushed a commit that will add another option ("+1") that lets you choose your pseudoshare difficulty, so you can fix it to some value.

By "adding to the username" you mean the username specified in bitcoin.conf (rpcuser=)?

Dia

I think he means the username sent by the miner. i.e. in cgminer instead of a username "user" you would use a username of "user /1300" to request 1300 difficulty work from p2pool.

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[dub0matic]

damn the day of blocks we got going on.

[stevegee58]

damn the day of blocks we got going on.

I ain't complainin'

[kjj]

The transition ~40 hours ago went better than expected. Thanks to all for upgrading.

Now that we're using the new implementation, miners can volunteer to raise their share difficulty by adding something like "/1300" to the end of their miners' usernames. The 1300 is the difficulty of your own shares, and can be changed but must be higher than P2Pool's difficulty (currently 650) to have any effect. I urge anyone whose variance is dominated by P2Pool's block finding to try this (which really means anyone who gets more than a few shares per hour). This has the effect of lowering P2Pool's difficulty for the benefit of small miners, which may let P2Pool grow further.

Last, a side note (mainly to DeathAndTaxes): I just pushed a commit that will add another option ("+1") that lets you choose your pseudoshare difficulty, so you can fix it to some value.

Am I correct in thinking that p2pool now provides variable size shares?  Will shares found that are higher than the current (network) difficulty automatically scale, or does it need to be set in advance?

[DeathAndTaxes]

Am I correct in thinking that p2pool now provides variable size shares?  Will shares found that are higher than the current (network) difficulty automatically scale, or does it need to be set in advance?

Well p2pool has always supported variable difficulty shares.  This simple lets you set a higher than minimum diff.  You would need to set it ahead of time.  If you don't cheating is trivially easy.  Look I just found a diff 200,000 shares woot.  I get credit for 40,000 shares!

[kjj]

Am I correct in thinking that p2pool now provides variable size shares?  Will shares found that are higher than the current (network) difficulty automatically scale, or does it need to be set in advance?

Well p2pool has always supported variable difficulty shares.  This simple lets you set a higher than minimum diff.  You would need to set it ahead of time.  If you don't cheating is trivially easy.  Look I just found a diff 200,000 shares woot.  I get credit for 40,000 shares!

Yeah, that's what I was getting at.  I just didn't want to spell it all out in public until I heard from forrestv that it was taken care of. 

[DeathAndTaxes]

Am I correct in thinking that p2pool now provides variable size shares?  Will shares found that are higher than the current (network) difficulty automatically scale, or does it need to be set in advance?

Well p2pool has always supported variable difficulty shares.  This simple lets you set a higher than minimum diff.  You would need to set it ahead of time.  If you don't cheating is trivially easy.  Look I just found a diff 200,000 shares woot.  I get credit for 40,000 shares!

Yeah, that's what I was getting at.  I just didn't want to spell it all out in public until I heard from forrestv that it was taken care of.  

Ah I see.  Oops.  Well looking over the code I the share difficulty is part of the block header. Thus diff is defined before hashing and once you find a share it is only good for that difficulty as you submit share data long w/ hash to the share chain to allow other nodes to verify.

[kano]

Wasn't that one of the 2 new points of this post?
https://bitcointalk.org/index.php?topic=18313.msg785010#msg785010

[DeathAndTaxes]

Wasn't that one of the 2 new points of this post?
https://bitcointalk.org/index.php?topic=18313.msg785010#msg785010

Yes that is what we are talking about.

[kano]

Wasn't that one of the 2 new points of this post?
https://bitcointalk.org/index.php?topic=18313.msg785010#msg785010

Yes that is what we are talking about.

So ... you were both wondering if he got it right or screwed it up?

[DeathAndTaxes]

Wasn't that one of the 2 new points of this post?
https://bitcointalk.org/index.php?topic=18313.msg785010#msg785010

Yes that is what we are talking about.

So ... you were both wondering if he got it right or screwed it up?

No and no.

[kjj]

Am I correct in thinking that p2pool now provides variable size shares?  Will shares found that are higher than the current (network) difficulty automatically scale, or does it need to be set in advance?

Well p2pool has always supported variable difficulty shares.  This simple lets you set a higher than minimum diff.  You would need to set it ahead of time.  If you don't cheating is trivially easy.  Look I just found a diff 200,000 shares woot.  I get credit for 40,000 shares!

Yeah, that's what I was getting at.  I just didn't want to spell it all out in public until I heard from forrestv that it was taken care of.  

Ah I see.  Oops.  Well looking over the code I the share difficulty is part of the block header. Thus diff is defined before hashing and once you find a share it is only good for that difficulty as you submit share data long w/ hash to the share chain to allow other nodes to verify.

The bitcoin network target is in the block header.  This is not the same as the p2pool target.

[sharky112065]

Does p2pool backup the log file before it wipes it and starts over? I noticed that around 10 AM my time this morning, that p2pool wiped my log file and started fresh (first entries are after 10 AM). I cannot find anywhere that it got backed up. Can you add an option to do log file backups?

[DeathAndTaxes]

Am I correct in thinking that p2pool now provides variable size shares?  Will shares found that are higher than the current (network) difficulty automatically scale, or does it need to be set in advance?

Well p2pool has always supported variable difficulty shares.  This simple lets you set a higher than minimum diff.  You would need to set it ahead of time.  If you don't cheating is trivially easy.  Look I just found a diff 200,000 shares woot.  I get credit for 40,000 shares!

Yeah, that's what I was getting at.  I just didn't want to spell it all out in public until I heard from forrestv that it was taken care of.  

Ah I see.  Oops.  Well looking over the code I the share difficulty is part of the block header. Thus diff is defined before hashing and once you find a share it is only good for that difficulty as you submit share data long w/ hash to the share chain to allow other nodes to verify.

The bitcoin network target is in the block header.  This is not the same as the p2pool target.

I was refering to the p2pool target not bitcoin target.  Obviously bitcoin diff is in the bitcoin header but that has nothing to do w/ p2pool allowing variable diff shares.

p2pool puts various pieces of data into the coinbase otherwise creating fake shares of higher difficulty would be trivial.

say p2pool difficulty is 500 and thus all shares of diff 500 are worth 500 "points" not 1 share.  I say point because since share diff is always changing p2pool doesn't split reward by # of shares it splits them by weighted workshare = # of shares * share difficulty.   Remember diff is constantly changing thus p2pool can't count all shares as equal otherwise a share when target is 400 = share when target is 500. 


If there was nothing put into the block header one could easily (I mean about 15 seconds of code changing) cheat the entire network by massive proportions.  When you find a share simply modify the share chain data to reflect diff as found not diff as trying.  So if you find a 500 diff share submit it as a 500 diff share.  If you find a 50,000 dif share submit it as a 50,000 dif share (worth 100x as much).  It doesn't take a rocket scientist to realize one could get 99.9999999% of the reward on every single block by cheating.

p2pool prevents this by choosing a share diff BEFORE hashing and encoding this in the coinbase.  Thus if you are looking for a 500 dif share and find one you can't "spoof" the network by sumbitting it as a 50,000 dif share because when validating each node will be unable to recreate the proper block hash and the share will be found invalid.   A share w/ target of 500 not can never be worth more than 500. 

TL/DR version:
Via the coinbase value p2pool encodes the diff of the share being searched.
If you are looking for a share of x diff it is only worth x.

[kano]

Wasn't that one of the 2 new points of this post?
https://bitcointalk.org/index.php?topic=18313.msg785010#msg785010

Yes that is what we are talking about.

So ... you were both wondering if he got it right or screwed it up?

No and no.

So ... for him yes and yes for you no and no.

[kano]

...
TL/DR version:
Via the coinbase value p2pool encodes the diff of the share being searched.
If you are looking for a share of x diff it is only worth x.

So ... what it also means is you can choose a share difficulty of whatever you like whenever you like and matching shares will now always be valid in the share chain ... as long as they are above the currently defined share difficulty.

[DeathAndTaxes]

...
TL/DR version:
Via the coinbase value p2pool encodes the diff of the share being searched.
If you are looking for a share of x diff it is only worth x.

So ... what it also means is you can choose a share difficulty of whatever you like whenever you like and matching shares will now always be valid in the share chain.

Correction:
you can choose any share difficulty >= target difficulty and they will be valid in the share chain.

[kano]

heh yeah I just changed that as you posted

[ThiagoCMC]

Hi!

 Since day 27 feb 2012, the patron_sendmany stops working for me... Just now I take notice of it...

 Look:

$ wget -O- http://192.168.10.1:9332/patron_sendmany?total=2.0 | more
--2012-03-06 02:08:05--  http://192.168.1.235:9332/patron_sendmany?total=200
Connecting to 192.168.1.235:9332... connected.
HTTP request sent, awaiting response... 200 OK
Length: 50 [text/plain]
Saving to: `STDOUT'

100%[===============================================================================================================================>] 50          --.-K/s   in 0s     

2012-03-06 02:08:05 (4.23 MB/s) - written to stdout [50/50]

need total argument. go to patron_sendmany/<TOTAL>


 For both Bitcoin 9332 and Litecoin 9327 I got this...

 Any tip!?

Thanks!
Thiago

[Diapolo]

The transition ~40 hours ago went better than expected. Thanks to all for upgrading.

Now that we're using the new implementation, miners can volunteer to raise their share difficulty by adding something like "/1300" to the end of their miners' usernames. The 1300 is the difficulty of your own shares, and can be changed but must be higher than P2Pool's difficulty (currently 650) to have any effect. I urge anyone whose variance is dominated by P2Pool's block finding to try this (which really means anyone who gets more than a few shares per hour). This has the effect of lowering P2Pool's difficulty for the benefit of small miners, which may let P2Pool grow further.

Last, a side note (mainly to DeathAndTaxes): I just pushed a commit that will add another option ("+1") that lets you choose your pseudoshare difficulty, so you can fix it to some value.

By "adding to the username" you mean the username specified in bitcoin.conf (rpcuser=)?

Dia

I think he means the username sent by the miner. i.e. in cgminer instead of a username "user" you would use a username of "user /1300" to request 1300 difficulty work from p2pool.

I guess we need a clarification for this ^^ ...

Dia