monero-pool

A Monero mining pool server written in C.

Design decisions are focused on performance and efficiency, hence the use of libevent and LMDB. Currently it uses only two threads under normal operation (one for the stratum clients and one for the web UI clients). It gets away with this thanks to the efficiency of both LMDB and libevent (for the stratum clients) and some sensible proxying/caching being placed in front of the web UI.

Configuration is extremely flexible, now allowing for the pool to run in a variety of setups, such as highly available and redundant configurations. Discussed further below in: Interconnected pools.

This pool was the first pool to support RandomX and is currently the only pool which supports the RandomX fast/full-memory mode.

The single payout mechanism is PPLNS, which favors loyal pool miners, and there are no plans to add any other payout mechanisms or other coins. Work should stay focussed on performance, efficiency and stability.

The pool also supports an optional method of mining whereby miners select their own block template to mine on. Further information can be found in the document: Stratum mode self-select.

For testing, a reference mainnet pool can be found at monerop.com.

Compiling from source

Dependencies

The build system requires the Monero source tree to be cloned and compiled. Follow the instructions for compiling Monero, then export the following variable:

export MONERO_ROOT=/path/to/cloned/monero

Replacing the path appropriately.

Beyond the Monero dependencies, the following extra libraries are also required to build the pool:

• liblmdb
• libevent
• json-c
• uuid

As an example, on Ubuntu, these dependencies can be installed with the following command:

sudo apt-get install liblmdb-dev libevent-dev libjson-c-dev uuid-dev

Compile

After installing all the dependencies as described above, to compile the pool as a release build, run:

make release

The application will be built in build/release/.

Optionally you can compile a debug build by simply running:

make

Debug builds are output in build/debug/.

Configuration

During compilation, a copy of pool.conf is placed in the output build directory. Edit this file as you see fit. When running the pool, if a custom location is not set via the command-line parameter --config-file <file>, the pool will first look for this file in the same directory as the pool binary, then in the current users home directory. The configuration options should all be self explanatory.

There are also some command-line parameters which can be used to override some of these settings.

Block notification

The pool can optionally be started with the flag --block-notified (or set in the config file: block-notified = 1). This will prevent the pool from polling for new blocks (using a timer), and instead fetch a new block template when it receives a signal (specifically, SIGUSR1). The Monero daemon, monerod, has a feature whereby it can execute a command whenever a block as added to the chain, which can thus be used to generate the required signal.

E.g.

monerod ... --block-notify '/usr/bin/pkill -USR1 monero-pool'

Launching monerod like this instructs it to send the required signal, SIGUSR1, to the pool whenever a new block is added to the chain.

Using this mechanism has a significant benefit - your pool immediately knows when to fetch a new block template to send to your miners. You're essentially giving your miners a head-start over miners in pools which use polling (which is what currently all the other pool implementations do).

Interconnected pools

In some situations it's desirable to run multiple pool instances that behave as one. Some examples being:

• When running a global public pool, it's desirable to offer extremely low-latency pool connections to geographically dispersed miners.
• When running a private pool across multiple data centers, it's desirable to make use of the internal site-to-site network makeup.
• Where there are multiple hosts available, it's desirable to offer extra redundancy.

To meet these needs, multiple instances of the pool can be run with each behaving either as an edge pool, an upstream pool, both (i.e. bridged) or a normal single pool.

Any pool that has an upstream pool configured does almost everything a normal pool does, with the exception that it offloads payout processing to its upstream pool, thus it relays validated shares and blocks to the upstream pool. In return, the upstream pool sends the combined pools stats, balance updates and handles the payout processing. Should an upstream become unreachable, the downstream pools continue as normal, then upon reconnection to the upstream, sends over the backlog of shares and blocks accumulated whilst the upstream was unreachable.

Configuration is fairly trivial. A pool that will allow downstream pools to connect to it, does so via the config file parameters trusted-listen, trusted-port and trusted-allowed. E.g.

trusted-listen = 10.0.0.1
trusted-port = 4244
trusted-allowed = 10.0.0.2,10.0.0.3

As share validation is performed on the edge pools, it's vitally important this trusted listener is secured. Ideally it's only bound to an internal / local network / private interface and specifying the IP addresses of the downstream pools allowed to connect to it (as in the example above). If the interface being bound to is already secured, the parameter trusted-allowed can be omitted.

Then the downstream pools (10.0.0.2 and 10.0.0.3 in the above example), need to include in their config files the parameters upstream-host and upstream-port. E.g.

upstream-host = 10.0.0.1
upstream-port = 4244

To create a bridged pool, use all five parameters discussed above. For example:

trusted-listen = 10.0.0.4
trusted-port = 4244
trusted-allowed = 10.0.0.5,10.0.0.6
upstream-host = 10.0.0.1
upstream-port = 4244

An example where bridging can be useful is for spanning network providers, e.g. using a global provider for the main pool hubs (the bridges) and local providers for edge pools within a territory.

Every pool, however configured, still needs RPC access to a Monero daemon. They can of course all be configured to use the same daemon, or for extra redundancy, make use of separate daemons. Downstream pools do not need RPC access to the pool's wallet, only the final upstream needs wallet access. If Stratum mode self-select is being offered, the pool wallet view key can be set in the downstream pool config files via the pool-view-key parameter, or by running a local view-only wallet RPC.

Running

Ensure you have your Monero daemon (monerod) and wallet RPC (monero-wallet-rpc) up and running with the correct host and port settings as defined in your pool config file.

It is highly recommended to run these on the same host as the pool server to avoid any network latency when their RPC methods are called.

Then simply cd build/[debug|release] and run ./monero-pool.

Command-line parameters

A few of the configuration options can be overridden via the following command-line parameters:

-c, --config-file <file>
-l, --log-file <file>
-b, --block-notified [0|1]
-d, --data-dir <dir>
-p, --pid-file <file>
-f, --forked [0|1]

Web UI

This project is not designed to be a one-stop solution for running a public pool; it is an highly efficient mining pool implementation. For a public pool, which typically entails having a fancy web UI, that part is down to you. There is howeveer a minimal web UI that gets served on the port specified in the config file. If you plan on running a public pool via this UI (or any other for that matter), it's advisable to use either Apache or Nginx as a proxy in front of this with some appropriate caching configured. The goal is to offload browser based traffic to something built for the task and allow the pool to focus on its primary function - serving miners.

If you intend to make changes to this minimal web UI, note that the HTML gets compiled into the pool binary. The single web page that gets served simply makes use of a JSON endpoint to populate the stats. Thus, a sensible option for your own web UI is to simply make use of that endpoint (for stats and balances), and keep your website completely separate, served by Apache or Nginx for example.

SSL

The pool has been tested behind both HAProxy and stunnel, so if you wish to provide SSL access to the pool, these are both good options and simple to setup. The reference pool makes use of HAProxy and port 4343 for SSL traffic.

The web UI, as mentioned above, should ideally be placed behind a caching proxy. Therefore SSL termination should be be configured there (i.e. in Apache/Nginx).

Help / Contact

If you need help setting up your own pool, you can find me (jtgrassie) on IRC in #monero-pool and many of the other Monero channels.

Supporting the project

This mining pool has no built-in developer donation (like other mining pool software has), so if you use it and want to donate, XMR donations to:

451ytzQg1vUVkuAW73VsQ72G96FUjASi4WNQse3v8ALfjiR5vLzGQ2hMUdYhG38Fi15eJ5FJ1ZL4EV1SFVi228muGX4f3SV

would be very much appreciated.

License

Please see the LICENSE file.