P2Pool

Each share contains a generation transaction that pays to the previous n shares, where n is the number of shares whose total work is equal to 3 times the average work required to solve a block, or 8640 (= 72 hours of shares), whichever is smaller. Payouts are weighted based on the amount of work each share took to solve, which is proportional to the p2pool difficulty at that time.

The block reward (currently 6.25 BTC) and the transaction fees are combined and apportioned according to these rules:

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.

In the event that a share qualifies as a block, this generation transaction is exposed to the Bitcoin network and takes effect, transferring each node its payout.

On P2Pool stales refer to shares which can't make it into the sharechain. Because the sharechain is 20 times faster than the Bitcoin chain many stales are common and expected. However, because the payout is PPLNS only your stale rate relative to other nodes is relevant; the absolute rate is not.

There are two reported kinds of stales in P2Pool: "DEAD ON ARRIVAL" shares and orphan shares. Dead shares were too old by the time they arrived at your local P2Pool. Very high dead rates can indicate miner misconfiguration. Orphan shares are shares which were not extended by the rest of the P2Pool network, because some other miner's share was accepted first. Very high orphan rates may indicate network connectivity problems.

The P2Pool console output shows your relative stale rate compared to other P2Pool miners in the 'Own efficiency' column:

2012-01-07 20:57:51.797420 Pool stales: 13% Own: 13±2% Own efficiency: 100±2%

When you first start P2Pool claimed efficiency will be low and the error bounds on this estimate will be large, but as it runs the numbers will converge to their correct values.

If your efficiency is unusually low, make sure your network connection isn't overloaded, that your miners support long polling and are not set to work for excessive amounts of time, and that your bitcoind has multiple connections.

Q: "Why does my miner report so many longpoll events when mining on p2pool? - P4Man"
A: "Once every ~30 seconds is normal. That is how often p2pool shares are generated (as opposed to ~10 min for bitcoin blocks) - cabin"

Q: "Do the 'orphan' and 'dead' shares in P2Pool's status display hurt me?"
A: They shouldn't - It's normal for some fraction of everyone's shares to end up orphaned or dead. Because payouts are calculated by counting how many shares you have relative to others, everyone with normal configurations is equally "hurt" by this. However, if you have a large proportion of stales, your payout will be hurt. You can see how well you're doing by looking at P2Pool's "Efficiency" (ex: Efficiency: ~110.6% (40-111%)). If 100% doesn't lie within the confidence interval at the end, something is probably wrong (with 95% confidence).

Q: "What do I do if my efficiency is low?"
A: Make sure the computers you're running P2Pool and the miner on have enough memory and CPU time. If you have a lot of dead shares or the "Local dead on arrival" number is higher than a few percent, that means that something is wrong with your miner. Check to make sure that it is one of the working versions in the Miners section on this page. Lower the intensity or raise the FPS of your miner. If you have a lot of orphan shares, something is wrong with P2Pool's P2P connection. Decrease the load on your internet connection or enable QoS (Quality of Service) on your router.

Q: What is PPLNS?
A: Pay-Per-Last-N-Shares is a payout method that is completely resistant to pool hoppers.

Q: Why am I not getting very many shares?!
A: The P2Pool difficulty is hundreds of times higher than on other pools. It can take time to get a share. P2Pool displays an estimate of how long you have to wait in the console output.

Q: Why does my miner say it has found a lot of shares but p2pool say I have only found a few?!
A: The real P2Pool difficulty is hundreds of times higher than on normal pools, but p2pool essentially lies to your miner and tells it to work on relatively easy shares so that it submits shares every few seconds instead of every few hours. P2Pool then ignores any submitted shares that don't match the real share difficulty. By doing this, P2Pool can more accurately report your local hash rate and you can see if you are having problems with too many stale shares quickly

Q: Why am I getting so many rejects?
A: You're using an incompatible miner. See the miners section here, increase your FPS on the miner, decrease the intensity, upgrade your miner, or try a different miner.

Q: What stops the pool operator or the block finder from stealing a block?
A: A block solution is only worth anything because its hash matches Bitcoin's target. Altering anything within the block will change its hash and make it worthless. If you are concerned about the pool operator stealing a block, you should try to inspect the source code of each new version.

Q: Why does it say "Generated?" I want to spend my coins now!
A: P2Pool includes payouts in generation transactions, which must mature (taking 120 blocks or 20 hours) before they can be spent. The reason for this is that a block could be orphaned, which would make its payout invalid and could reverse transactions.

Q: Do I get paid transaction fees?
A: Yes. They are split among P2Pool miners.

Q: What are these payments I'm getting that aren't generated?
A: These are subsidies that people who support the idea of P2Pool send to miners.

Q: Cool Subsidies sound like an awesome idea! How do I send some BTC to these awesome miners?
A: See end of this page.

Q: Do I really need the WHOLE blockchain?
A: Yes. Your node needs to be able to independently make decisions about what transactions to mine.

Q: How do merged mining payments work?
A: Merged mining is handled entirely by namecoind, so you're solo mining and payouts will go into namecoind's wallet.

This is all for the latest p2pool version, as it includes several new workarounds.

With all miners, using a HIGH FPS target (100?) or a LOW intensity (8 for bfgminer?) helps a lot with reducing stales.

• bfgminer, cgminer, and ufasoft work perfectly without any extra options.
• DiabloMiner works fine after commit 3b731b9.
• Phoenix works fine after commit a658ef2.
• Poclbm works fine after commit 5e994e7.

P2Pool uses higher difficulty shares than most centralized pools, so you'll see fewer shares reported. This is normal and doesn't reduce your payments. It's also normal to see longpoll messages once per every ten seconds on average.

• "gpu-threads" : "1", (2 by default)
• "queue" : "0", (1 by default)

Because of fast longpooling in p2pool it is better not NOT fetch work ahead.

On non-dedicated machines intensity=3 allows normal usage of PC, set it to 7 or more to get full hashrate.

On most cards best is diablo and phatk kernel, looks like poclbm kernel have unstable rate.

• If upgrading P2Pool or changing its configuration, you can start another instance of P2Pool in parallel with the first. It will start normally, but realize that the worker and P2P listening ports are busy and keep trying to bind to them in the background. Thus, you can do almost-completely-seamless upgrades of P2Pool.
• If you run multiple P2Pool nodes or have trusted friends that run P2Pool, you can use -n to establish a constant extra P2P connection to them.
• You can make P2Pool use a configuration file by running run_p2pool.py @FILENAME, with FILENAME being the path to a file containing the command-line arguments (newlines are ignored) Example:

--net bitcoin
-n 1.2.3.4

• Setting the username of your miner connecting to P2Pool to a Bitcoin address will make it mine to that address instead of the one requested from bitcoind or set by -a
• Appending "/1000" to a miner's username will increase the difficulty of producing a P2Pool share to at most 1000. This is useful to large miners because doing this can make it easier for small miners while minimally impacting the large miners themselves. See recommended values.
  • Appending "+1" (for example) after that will make P2Pool always give your miners work with a difficulty of 1

Lots of data and useful tools are available at http://127.0.0.1:9332/something:

• /static/ - Lots of information from shares to graphs to payouts.
• /rate
• /users
• /fee
• /current_payouts
• /patron_sendmany - Gives sendmany outputs for fair donations to P2Pool
• /global_stats
• /local_stats
• /peer_addresses
• /payout_addr
• /recent_blocks
• /uptime
• /web/log - Some different stats collected over the last day

usage: run_p2pool.py [-h] [--version] [--net {bitcoin,litecoin}] [--testnet]
                     [--debug] [-a ADDRESS] [--datadir DATADIR]
                     [--logfile LOGFILE] [--merged MERGED_URLS]
                     [--give-author DONATION_PERCENTAGE] [--iocp]
                     [--irc-announce] [--no-bugreport] [--p2pool-port PORT]
                     [-n ADDR[:PORT]] [--disable-upnp] [--max-conns CONNS]
                     [-w PORT or ADDR:PORT] [-f FEE_PERCENTAGE]
                     [--bitcoind-address BITCOIND_ADDRESS]
                     [--bitcoind-rpc-port BITCOIND_RPC_PORT]
                     [--bitcoind-p2p-port BITCOIND_P2P_PORT]
                     [BITCOIND_RPCUSERPASS [BITCOIND_RPCUSERPASS ...]]

p2pool (version 0.11.1-8-ged9359d)

optional arguments:
  -h, --help            show this help message and exit
  --version             show program's version number and exit
  --net {bitcoin,litecoin}
                        use specified network (default: bitcoin)
  --testnet             use the network's testnet
  --debug               enable debugging mode
  -a ADDRESS, --address ADDRESS
                        generate payouts to this address (default: <address
                        requested from bitcoind>)
  --datadir DATADIR     store data in this directory (default: <directory
                        run_p2pool.py is in>/data)
  --logfile LOGFILE     log to this file (default: data/<NET>/log)
  --merged MERGED_URLS  call getauxblock on this url to get work for merged
                        mining (example:
                        http://ncuser:ncpass@127.0.0.1:10332/)
  --give-author DONATION_PERCENTAGE
                        donate this percentage of work towards the development
                        of p2pool (default: 0.5)
  --iocp                use Windows IOCP API in order to avoid errors due to
                        large number of sockets being open
  --irc-announce        announce any blocks found on
                        irc://irc.freenode.net/#p2pool
  --no-bugreport        disable submitting caught exceptions to the author
  --disable-upnp        don't attempt to use UPnP to forward p2pool's P2P port
                        from the Internet to this computer

p2pool interface:
  --p2pool-port PORT    use port PORT to listen for connections (forward this
                        port from your router!) (default: bitcoin:9333,
                        litecoin:9338)
  -n ADDR[:PORT], --p2pool-node ADDR[:PORT]
                        connect to existing p2pool node at ADDR listening on
                        port PORT (defaults to default p2pool P2P port) in
                        addition to builtin addresses
  --max-conns CONNS     maximum incoming connections (default: 40)

worker interface:
  -w PORT or ADDR:PORT, --worker-port PORT or ADDR:PORT
                        listen on PORT on interface with ADDR for RPC
                        connections from miners (default: all interfaces,
                        bitcoin:9332, litecoin:9327)
  -f FEE_PERCENTAGE, --fee FEE_PERCENTAGE
                        charge workers mining to their own bitcoin address (by
                        setting their miner's username to a bitcoin address)
                        this percentage fee to mine on your p2pool instance.
                        Amount displayed at http://127.0.0.1:WORKER_PORT/fee
                        (default: 0)

bitcoind interface:
  --bitcoind-address BITCOIND_ADDRESS
                        connect to this address (default: 127.0.0.1)
  --bitcoind-rpc-port BITCOIND_RPC_PORT
                        connect to JSON-RPC interface at this port (default:
                        bitcoin:8332, litecoin:9332 <read from bitcoin.conf if
                        password not provided>)
  --bitcoind-p2p-port BITCOIND_P2P_PORT
                        connect to P2P interface at this port (default:
                        bitcoin:8333, litecoin:9333 <read from bitcoin.conf if
                        password not provided>)
  BITCOIND_RPCUSERPASS  bitcoind RPC interface username, then password, space-
                        separated (only one being provided will cause the
                        username to default to being empty, and none will
                        cause P2Pool to read them from bitcoin.conf)