check_servers.py

#!/usr/bin/python
# author slush, public domain
from twisted.internet import reactor
from twisted.internet import defer

from stratum import settings
settings.LOGLEVEL = 'INFO'

from stratum.socket_transport import SocketTransportClientFactory
from stratum.services import GenericService, ServiceEventHandler
from stratum.connection_registry import ConnectionRegistry

import time

debug = False
reg = {}

class BlockchainNumblocks(GenericService):
    service_type = 'blockchain.numblocks'
    service_vendor = 'custom'
    is_default = True

    def subscribe(self, blocks):
        session = ConnectionRegistry.get_session(self)
        session['blocks'] = blocks

        print session['hostname'], "Received notification for the numblocks event !!!", blocks

'''
class ServerPeers(GenericService):
    service_type = 'server.peers'
    service_vendor = 'custom'
    is_default = True

    @defer.inlineCallbacks
    def subscribe(self, peers):
        print "New peers", peers
	yield add_peers(peers)
'''

@defer.inlineCallbacks
def connect(hostname):
    # Try to connect to remote server
    f = SocketTransportClientFactory(hostname, 50001,
                allow_trusted=True,
                allow_untrusted=False,
                debug=debug,
                signing_key=None,
                signing_id=None,
                event_handler=ServiceEventHandler)
    try:
        yield f.on_connect # Wait to on_connect event
    except:
        print "Failed to connect to", hostname
        return

    reg[hostname] = f

    r1 = f.rpc('blockchain.numblocks.subscribe', [])
    r2 = f.rpc('server.peers.subscribe', [])

    blocks = (yield r1)
    print hostname, 'numblocks', blocks

    session = ConnectionRegistry.get_session(f.client)
    session['hostname'] = hostname
    session['blocks'] = blocks

    peers = [ server[1] for server in (yield r2) ]
    yield add_peers(peers)

@defer.inlineCallbacks
def add_peers(peers):
    for peer in peers:
        if peer not in reg:
            print "Adding peer", peer
            yield connect(peer)

def check_blocks():
    #print "Checking if all servers have up-to-date blockchain"
    max_blocks = 0
    for f in reg.values():
        session = ConnectionRegistry.get_session(f.client)
        max_blocks = max(max_blocks, session.get('blocks', 0))

    for f in reg.values():
        session = ConnectionRegistry.get_session(f.client)
	if session['blocks'] < max_blocks - 1:
            print '!!!', session['hostname'], '(%d) is behind other servers (%d)!' % (session['blocks'], max_blocks)

    reactor.callLater(10, check_blocks)

if __name__ == '__main__':
    connect('california.stratum.bitcoin.cz')
    connect('ecdsa.org')
    check_blocks()
    reactor.run()