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dcrpool

Overview

dcrpool is a stratum Decred mining pool. It supports BLAKE3 mining as required by DCP0011.

The default port all supported miners connect to the pool via is :5550. The pool can be configured to mine in solo pool mode or as a publicly available mining pool. Solo pool mode represents a private mining pool operation where all connected miners to the pool are owned by the pool administrator. For this reason, mining rewards are left to accumulate at the specified address for the mining node. There isn't a need for payment processing in solo pool mining mode, it is disabled as a result.

In solo pool mining mode, miners only need to identify themselves when connecting to the pool. The miner's username, specifically the username sent in a mining.authorize message, should be a unique name identifying the client.

The pool supports Pay Per Share (PPS) and Pay Per Last N Shares (PPLNS) payment schemes when configured for pool mining. With pool mining, mining clients connect to the pool, contribute work towards solving a block and claim shares for participation. When a block is found by the pool, portions of the mining reward due participating accounts are calculated based on claimed shares and the payment scheme used. The pool pays out the mining reward portions due each participating account when it matures.

In addition to identifying itself to the pool, each connecting miner has to specify the address its portion of the mining reward should be sent to when a block is found. For this reason, the mining client's username is a combination of the address mining rewards are paid to and its name, formatted as: address.name. This username format for pool mining is required. The pool uses the address provided in the username to create an account, all other connected miners with the same address set will contribute work to that account.

The user interface of the pool provides public access to statistics and pool account data. Users of the pool can access all payments, mined blocks by the account and also work contributed by clients of the account via the interface. The interface is only accessible via HTTPS and by default uses a self-signed certificate, served on port :8080. In production, particularly for pool mining, a certificate from an authority (CA) like letsencrypt is recommended.

Build and installation

• Install Go 1.21 or higher

  Installation instructions can be found here: https://golang.org/doc/install. Ensure Go was installed properly and is a supported version:

  $ go version
  $ go env GOROOT GOPATH
  

  NOTE: if GOROOT and GOPATH are initialized they must not be at the same path. It is recommended to add $GOPATH/bin to your PATH according to the Golang.org instructions.

• Build and Install or Update dcrpool

  The latest release of dcrpool may be built and installed with a single command without cloning this repository:

  $ go install github.com/decred/dcrpool@release-v2.0.0
  

  Using @master instead will perform a build using the latest code from the master branch. This may be useful to use newer features or bug fixes not yet found in the latest release:

  $ go install github.com/decred/dcrpool@master
  

  Alternatively, a development build can be performed by running go install in a locally checked-out repository.

  In all cases, the dcrpool executable will be installed to the bin directory rooted at the path reported by go env GOPATH.

  Therefore, if you want to easily access dcrpool from the command-line without having to type the full path to the binary every time, ensure the aforementioned directory is added to your system path:

  • macOS: how to add binary to your PATH
  • Windows: how to add binary to your PATH
  • Linux and other Unix: how to add binary to your PATH

Database

dcrpool can run with either a Bolt database or a Postgres database. Bolt is used by default. postgres.md has more details about running with Postgres.

When running in Bolt mode, the pool maintains a backup of the database (backup.kv), created on shutdown in the same directory as the database itself. The user interface also provides functionality for pool administrators to backup Bolt database when necessary.

Configuration

dcrpool requires dcrd and dcrwallet when configured as a mining pool, it only requires dcrd when configured as a solo pool. Deploying the user interface requires copying the dcrpool/internal/gui/assets folder from source to a reachable location and updating the gui directory (--guidir) of the configuration. Currently only single instance deployments are supported, support for distributed deployments will be implemented in the future.

Example of a solo pool configuration

rpcuser=user
rpcpass=pass
dcrdrpchost=127.0.0.1:9109
dcrdrpccert=/home/.dcrd/rpc.cert
solopool=true
activenet=mainnet
adminpass=adminpass
guidir=/home/gui

The configuration above uses a Bolt database. To switch to a Postgres database additional config options will be needed, refer to postgres.md.

Example output of a solo pool startup

dcrpool --configfile=pool.conf --appdata=/tmp/dcrpool-harness/pool
2023-09-19 20:10:31.149 [INF] MP: Version: 1.3.0-pre+88afbe8d1 (Go version go1.21.1 linux/amd64)
2023-09-19 20:10:31.149 [INF] MP: Home dir: /tmp/dcrpool-harness/pool
2023-09-19 20:10:31.120 [INF] POOL: Maximum work submission generation time at pool difficulty is 28s.
2023-09-19 20:10:31.149 [INF] MP: Creating profiling server listening on 127.0.0.1:6060
2023-09-19 20:10:31.129 [INF] POOL: Solo pool mode active.
2023-09-19 20:10:31.150 [INF] POOL: listening on 0.0.0.0:5550
2023-09-19 20:10:31.149 [INF] GUI: Starting GUI server on [::]:8080

Example of a mining pool configuration

rpcuser=user
rpcpass=pass
dcrdrpchost=127.0.0.1:9109
dcrdrpccert=/home/.dcrd/rpc.cert
walletgrpchost=127.0.0.1:9111
walletrpccert=/home/.dcrwallet/rpc.cert
maxgentime=20s
solopool=false
activenet=mainnet
walletpass=walletpass
poolfeeaddrs=SsVPfV8yoMu7AvF5fGjxTGmQ57pGkaY6n8z
paymentmethod=pplns
lastnperiod=5m
adminpass=adminpass
guidir=/home/gui

The configuration above uses a Bolt database. To switch to a Postgres database additional config options will be needed, refer to postgres.md.

Example output of a mining pool startup

dcrpool --configfile=pool.conf --appdata=/tmp/dcrpool-harness/pool
2023-09-19 19:57:45.916 [INF] MP: Version: 1.3.0-pre+88afbe8d1 (Go version go1.21.1 linux/amd64)
2023-09-19 19:57:45.916 [INF] MP: Home dir: /tmp/dcrpool-harness/pool
2023-09-19 19:57:45.795 [INF] POOL: Maximum work submission generation time at pool difficulty is 20s.
2023-09-19 19:57:45.916 [INF] MP: Creating profiling server listening on 127.0.0.1:6060
2023-09-19 19:57:45.816 [INF] POOL: Payment method is PPLNS.
2023-09-19 19:57:45.917 [INF] GUI: Starting GUI server on [::]:8080
2023-09-19 19:57:45.932 [INF] POOL: listening on 0.0.0.0:5550

Refer to config descriptions for more detail.

Wallet accounts

In mining pool mode the ideal wallet setup is to have two wallet accounts, the pool account and the fee account, for the mining pool. This account structure separates revenue earned from pool operations from mining rewards received on behalf of participating clients. The pool account's purpose is to receive mining rewards of the pool. The addresses generated from it should be the mining addresses (--miningaddr) set for the mining node. It is important to set multiple mining addresses for the mining node in production to make it difficult for third-parties wanting to track coinbases mined by the pool and ultimately determine the cumulative value of coinbases mined.

The fee account's purpose is to receive pool fees of the mining pool. It is important to set multiple pool fee addresses to the mining pool in production to make it difficult for third-parties wanting to track pool fees collected by the pool and ultimately determine the cumulative value accrued by pool operators. With multiple pool fee addresses set, the mining pool picks one at random for every payout made. The addresses generated from the fee account should be set as the pool fee addresses (--poolfeeaddrs) of the mining pool.

Wallet Client Authentication

dcrwallet v1.6 and greater requires client authentication certificates to be provided on startup via the client CA file config option (--clientcafile). Since dcrpool is expected to maintain a grpc connection to the wallet it needs to generate the needed certificate before the wallet is started. A config option (--gencertsonly) which allows the generation of all key pairs without starting the pool has been added for this purpose. Pool operators running a publicly available mining pool will be required to first run their pools with --gencertsonly to generate required key pairs before configuring their pool wallets and starting them. The test harness, harness.sh, provides a detailed example for reference.

Pool Fees

In mining pool mode pool fees collected by the pool operator are for maintaining a connection to the decred network, the delivery of work to mining clients, the submission of solved work by mining clients to the network, and processing of block rewards based on work contributed by participting accounts.

Transaction fees

Every mature group of payments plus the pool fees collected completely exhaust the referenced coinbases being sourced from by payments. For this reason payout transactions by the pool create no change. It is implicit that the transaction fees of the payout transaction are paid for by the accounts receiving payouts, since transaction fees are not collected as part of pool fees. Each account receiving a payout from the transaction pays a portion of the transaction fee based on value of the payout in comparison to the overall value of payouts being made by the transaction.

Dust payments

Dust payments generated by participating accounts of the pool are forfeited to the pool fees paid per each block mined. The reason for this is two-fold. Dust payments render payout transactions non-standard causing it to fail, also making participating accounts forfeit dust payments serves as a good deterrent to accounts that contribute intermittent, sporadic work. Participating accounts become compelled to commit and contribute enough resources to the pool worth more than dust outputs to guarantee receiving dividends whenever the pool mines a block.

Testing

The project has a configurable tmux mining harness and a CPU miner for testing on simnet. Further documentation can be found in harness.sh.

Should I be running dcrpool?

dcrpool is ideal for miners running medium-to-large mining operations. The revenue generated from mining blocks as well as not paying pool fees to a publicly available mining pool in the process should be enough to offset the cost of running a pool. It will most likely not be cost effective to run dcrpool for a small mining operation, the better option here would be using a public mining pool instead.

For people looking to setup a publicly available mining pool, dcrpool's well-documented configuration and simple setup process also make it a great option.

Contact

If you have any further questions you can find us at https://decred.org/community/.

Issue Tracker

The integrated github issue tracker is used for this project.

License

dcrpool is licensed under the copyfree ISC License.