Prometheus exporter for monitoring statistics of Bitcoin daemon

bitcoin-monitor.md

bitcoind-monitor.py

This is a script written in Python intended to run alongside a Bitcoin node and export statistics for monitoring purposes. It assumes the existence of bitcoin-cli in the PATH and access to the RPC interface over localhost.

It tracks stuff like: block height, difficulty, number of peers, network hash rate, errors, uptime in seconds, mempool size, size of recent blocks, number of transactions within blocks, chaintips, total bytes received and sent, and transaction inputs and outputs. These Bitcoin metrics are refreshed once every 5 minutes.

How it works

Prometheus is a monitoring system and time-series database.

It works by pulling or scraping numerical metrics from an HTTP endpoint (or "exporter"), and then ingesting and keeping track of them over time.

You can then build queries and alerting rules from this data. This code is targeted to users of both Prometheus and Bitcoin.

An exporter setup as a scrape target may be local or remote. Prometheus is a great backend for a visualization and analytics software such as Grafana.

Testing and requirements

To see it in action, run bitcoind-monitor.py and navigate to http://127.0.0.1:8334 in your browser.

Ensure that prometheus_client is installed via pip. If you're using Python 2, then the whichcraft module is another requirement.

Running as a service

I'd also recommend running this persistently as a systemd service. For example:

[Unit]
Description=bitcoind-monitor
After=network.target bitcoind.service

[Service]
ExecStart=/usr/bin/python /usr/local/bin/bitcoind-monitor.py
KillMode=process
User=bitcoin
Group=bitcoin
Restart=on-failure

[Install]
WantedBy=multi-user.target

bitcoind-monitor.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

import json
import time
import subprocess
import sys
from prometheus_client import start_http_server, Gauge, Counter

# Create Prometheus metrics to track bitcoind stats.
BITCOIN_BLOCKS = Gauge('bitcoin_blocks', 'Block height')
BITCOIN_DIFFICULTY = Gauge('bitcoin_difficulty', 'Difficulty')
BITCOIN_PEERS = Gauge('bitcoin_peers', 'Number of peers')
BITCOIN_HASHPS = Gauge('bitcoin_hashps', 'Estimated network hash rate per second')

BITCOIN_ERRORS = Counter('bitcoin_errors', 'Number of errors detected')
BITCOIN_UPTIME = Gauge('bitcoin_uptime', 'Number of seconds the Bitcoin daemon has been running')

BITCOIN_MEMPOOL_BYTES = Gauge('bitcoin_mempool_bytes', 'Size of mempool in bytes')
BITCOIN_MEMPOOL_SIZE = Gauge('bitcoin_mempool_size', 'Number of unconfirmed transactions in mempool')

BITCOIN_LATEST_BLOCK_SIZE = Gauge('bitcoin_latest_block_size', 'Size of latest block in bytes')
BITCOIN_LATEST_BLOCK_TXS = Gauge('bitcoin_latest_block_txs', 'Number of transactions in latest block')

BITCOIN_NUM_CHAINTIPS = Gauge('bitcoin_num_chaintips', 'Number of known blockchain branches')

BITCOIN_TOTAL_BYTES_RECV = Gauge('bitcoin_total_bytes_recv', 'Total bytes received')
BITCOIN_TOTAL_BYTES_SENT = Gauge('bitcoin_total_bytes_sent', 'Total bytes sent')

BITCOIN_LATEST_BLOCK_INPUTS = Gauge('bitcoin_latest_block_inputs', 'Number of inputs in transactions of latest block')
BITCOIN_LATEST_BLOCK_OUTPUTS = Gauge('bitcoin_latest_block_outputs', 'Number of outputs in transactions of latest block')

def find_bitcoin_cli():
    if sys.version_info[0] < 3:
        from whichcraft import which
    if sys.version_info[0] >= 3:
        from shutil import which
    return which('bitcoin-cli')

BITCOIN_CLI_PATH = str(find_bitcoin_cli())

def bitcoin(cmd):
    bitcoin = subprocess.Popen([BITCOIN_CLI_PATH, cmd], stdout=subprocess.PIPE, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
    output = bitcoin.communicate()[0]
    return json.loads(output.decode('utf-8'))


def bitcoincli(cmd):
    bitcoin = subprocess.Popen([BITCOIN_CLI_PATH, cmd], stdout=subprocess.PIPE, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
    output = bitcoin.communicate()[0]
    return output.decode('utf-8')


def get_block(block_height):
    try:
        block = subprocess.check_output([BITCOIN_CLI_PATH, 'getblock', block_height])
    except Exception as e:
        print(e)
        print('Error: Can\'t retrieve block number ' + block_height + ' from bitcoind.')
        return None
    return json.loads(block.decode('utf-8'))


def get_raw_tx(txid):
    try:
        rawtx = subprocess.check_output([BITCOIN_CLI_PATH, 'getrawtransaction', txid, '1'])
    except Exception as e:
        print(e)
        print('Error: Can\'t retrieve raw transaction ' + txid + ' from bitcoind.')
        return None
    return json.loads(rawtx.decode('utf-8'))


def main():
    # Start up the server to expose the metrics.
    start_http_server(8334)
    while True:
        info = bitcoin('getinfo')
        chaintips = len(bitcoin('getchaintips'))
        mempool = bitcoin('getmempoolinfo')
        nettotals = bitcoin('getnettotals')
        latest_block = get_block(str(info['blocks']))
        hashps = float(bitcoincli('getnetworkhashps'))

        BITCOIN_BLOCKS.set(info['blocks'])
        BITCOIN_PEERS.set(info['connections'])
        BITCOIN_DIFFICULTY.set(info['difficulty'])
        BITCOIN_HASHPS.set(hashps)

        if info['errors']:
            BITCOIN_ERRORS.inc()

        BITCOIN_NUM_CHAINTIPS.set(chaintips)

        BITCOIN_MEMPOOL_BYTES.set(mempool['bytes'])
        BITCOIN_MEMPOOL_SIZE.set(mempool['size'])

        BITCOIN_TOTAL_BYTES_RECV.set(nettotals['totalbytesrecv'])
        BITCOIN_TOTAL_BYTES_SENT.set(nettotals['totalbytessent'])

        if latest_block is not None:
            BITCOIN_LATEST_BLOCK_SIZE.set(latest_block['size'])
            BITCOIN_LATEST_BLOCK_TXS.set(len(latest_block['tx']))
            inputs, outputs = 0, 0
            # counting transaction inputs and outputs requires txindex=1
            # to be enabled, which may also necessitate reindex=1 in bitcoin.conf
            for tx in latest_block['tx']:

                if get_raw_tx(tx) is not None:
                    rawtx = get_raw_tx(tx)
                    i = len(rawtx['vin'])
                    inputs += i
                    o = len(rawtx['vout'])
                    outputs += o

            BITCOIN_LATEST_BLOCK_INPUTS.set(inputs)
            BITCOIN_LATEST_BLOCK_OUTPUTS.set(outputs)

        time.sleep(300)

if __name__ == '__main__':
    main()