Topic: [1500 TH] p2pool: Decentralized, DoS-resistant, Hop-Proof pool - page 45. (Read 2591916 times)

This is based on the fact that LukeJr is a crappy coder and came up with the idea that a block change with transactions is slow, so do not put transaction in the first work.

This is of course bullshit.

It's more an issue of processing and propagation latency than mempool size. P2pool (along with most other pools) has code in it to generate empty blocks when the pool has heard of a new block header on the network, but has not yet gotten a block template from bitcoind. bitcoind can't generate a new block template until after it has fully downloaded and verified the previous block, since otherwise it might include transactions twice or include double-spends. Since downloading a block header is faster than downloading and verifying a full block, there can sometimes be a substantial amount of time in between where the best you can do is mine an empty block. The idea is that if you have a miner hashing on something, it's better to hash on an empty block at the right height than a full block at the wrong height (which would result in an orphan race). This condition should only last for a few seconds, though. The 23 actual seconds that elapsed seems excessive. It's possible that I need to do something to improve block propagation latency on that node. It's also possible that p2pool didn't poll getblocktemplate frequently enough or something.

If this happens when blocks are found in the first 30 15 seconds of mining, that would correspond to a 5% 2.5% reduction in average transactions included. That seems undesirable, but not excessive. The alternative -- mining on the wrong block height for up to 15 seconds -- sounds worse. I wish I had time to look into this more and improve performance, but at the moment I don't.

Edit: It appears that the timestamps on the blocks are wrong. This is pretty common, as generally timestamps are set when the stratum job is issued to the miner, not when the miner actually finds the block. Here's what shows up in my bitcoind logs:


Then, in my p2pool logs:


It's worth noting that this was a DOA share that happened to be a block. P2pool learned of the block at height 468172 at 3m20s, bitcoind learned of it 12 seconds later at 3m32s and had work for p2pool around that time, but p2pool didn't have it bundled into a stratum job until 3m34.7s. While p2pool was bundling the stratum job, a miner returned the block from the previous stratum job, and p2pool didn't process it until after it finished assigning the new work because p2pool is single-threaded. This means that the block was found at some point between 3m32s and 3m34.7s.

This node was running CPython, not pypy, because that server is running low on RAM. This may have contributed to the slow (2.7s) processing of new work, and increases the likelihood of a DOA share.

So in this case, we're talking about a 15 second time window, not 30 or 24. Of those 15 seconds, 12 seconds were due to bitcoind being a bit slow, and 3 seconds were due to p2pool being slow. Overall, I think finding an empty block in this scenario is a reasonable outcome, and do not consider this to be a priority for optimization right now.

With 110 MB of transactions waiting in the Bitcoin mempool during that time. jtoomimnet should've been able to fill its transaction cache back up to capacity with the share that found block 468173, but apparently did not.

Well, there was only 24 seconds between block 468172 and 468173.

Empty block by jtoomimnet.

Queue the block dance guy ......

use a preformated NTP list : http://www.prunoqi.com/~probruno/WORD/Liste%20des%20serveurs%20de%20temps%20SNTP%20disponibles%20sur%20Internet.htm

LTC now requires SegWit, which requires veqtrus's PR. It would take some more work to get LTC working with both my code and veqtrus's. It would need to be a different alt for testing.

At the moment, I'm more interested in the memory issues and the share size issues than in doing testing and merging. I'd also like to add some code that checks the system clock against NTP (when reachable) at startup in order to reduce the clock offset issues that people have been having, and I think that might be good to do before merging into p2pool master.

That's good.
And what about the p2pool ltc node testing and then the
merge into only one p2pool powerfull bitcoin sharechain?

Quick reminder: the jtoomimnet 1mb_hardforked branch of p2pool uses about 2x as much RAM, since the share chain contains around 2x as many transactions. If you are using pypy, this means that your memory consumption may get up to 6 GB. If you're using CPython, it's a little under 1 GB. Please make sure that you have enough RAM in your nodes. If you don't have enough RAM, you will get massive swapping, and you might notice that bitcoind is unable to keep up with blocks and may fall behind, causing p2pool to stop working.

Lowering RAM usage is my next goal for p2pool.

This P2Pool guide should be able to help. It's a lot more beginner-friendly than the Bitcoin wiki's article.
And here is an up-to-date list of public P2Pool nodes that you can connect your miners to, if you decide to not run your own P2Pool node.


Yes, in a sense. There are multiple P2Pool nodes, and all of them make up the P2Pool network. It is very similar to how the Bitcoin network works, where multiple Bitcoin full nodes make up the Bitcoin network.


P2Pool is a decentralized pool, similar to how Bitcoin is a decentralized network. There is therefore no main or central server, nor nodes that make up a main or central server. There is only the network of P2Pool nodes.

In other words, try to look at it according to what in2tactics said: each P2Pool node is its own pool. The P2Pool network connects these nodes together through the P2Pool sharechain, similar to how the Bitcoin network connects every Bitcoin full node together through the Bitcoin blockchain. P2Pool can therefore also be described as a collection of solo miners that pool block payouts and distribute them accordingly, since each P2Pool node is essentially doing its own thing. Contrast this to a traditional pool, where the central pool server dictates what its miners do.

Each node is its own pool. p2pool is a collection of pools. You can either make your own node or use another.

Hello,

I'm still trying to understand how P2Pool works. How do I find a list of P2Pool servers? The idea is that I make a node and connect to a server, right? I can't quite visualize how all of this works, despite looking on Google for information visualizations. The image I saw on the Bitcoin wiki didn't make much sense, seemed too technical.

There are multiple servers, right?

Is there like one main server? Or do a bunch of nodes together make the server?

I read and read but it doesn't stick/make-sense. So, hopefully, I can talk to people about this.

so that it need waiting around 13 days to payout huh?(◕‿◕)

Technically, the guy/gal/dog who submits the winning share DOES get the larger percentage of the proverbial pie, or at least used to, in the form of a 0.5% incentive. I don't know if that's still coded in or not though.

From the P2Pool Wiki: A subsidy of 0.5% is sent to the node that solved the block in order to discourage not sharing solutions that qualify as a block. (A miner with the aim to harm others could withhold the block, thereby preventing anybody from getting paid. He can NOT redirect the payout to himself.) The remaining 99.5% is distributed evenly to miners based on work done recently.

Ok that mean fair on share wahaha. nice p2pool you are great. i see last time friday is 4 Ph/s now why become 2 Ph/s wahaha....(◕‿◕)


is that mean p2pool adresss or something?when i used another address can't run when p2pool adress from generated tools. only that workingo(≧▽≦)o

No, I thought it was the former, but it had me questioning a bit. Technically the scenario of paying more for bigger shares would not be logical as the guy/gal/dog who submits the winning share would get a larger percentage of the proverbial pie.

I don't understand every nuance, my specialty is hacking and fixing the mining hardware. That I'm good at :-)

Rentals are only sustainable if they're hitting blocks on a regular basis. The price of rentals also rises with demand. Most likely scenario is the rented hash that was contributing to P2Pool ran out and the cost vs. profit was too great a ratio to justify another week of 'maybe a block'

Can someone explain the drop in hashing power pointed to p2pool?  I saw someone else mention it was up to 12PH and now it's hovering between 2-3PH.  Did I miss something? 

Everyone go back to a centralized pool?  What the hay??

To whomever is mining on ml.toom.im:9332 with address 3GU89xZmzJfCBXFzbB3mC2dsxDyKqrD7nz:

P2pool does not support multisig or P2SH addresses. Any worker name that is not a regular P2PKH address (starting with a 1) ends up contributing to the default address for that node. In other words, you're mining into my wallet, not your own.

I'll send you the 0.125 btc you made in the last block soon-ish (few days? I don't currently have access to that wallet), but I think everyone would be happier if you mined directly into your own address. Edit: sent.