Twisted XMLRPC proxy - twisted

Question

I'd like to make XMLRPC proxy with balancer using twisted.
[XMLRPC Server 1_1 8.8.8.8:8000] <--> [----------------------] <--- Client
[Proxy example.com:8000] <--- Client
[XMLRPC Server 1_2 9.9.9.9:8000] <--> [----------------------] <--- Client
So there are two XMLRPC instances which represents same methods. I need xmlrpc-proxy between this instances and clients. One more thing - this proxy should also accept JSON calls (kind of http://example.com:8000/RPC2, http://example.com:8000/JSON).
Right now I was trying to implement XMLRPC proxy calls. I can't receive answer back to client although sendLine() is calling.
import argparse
from twisted.internet import protocol, reactor, defer, threads
from twisted.web import xmlrpc
from twisted.internet.task import LoopingCall
from twisted.internet.defer import DeferredQueue, Deferred, inlineCallbacks
from twisted.protocols.basic import LineReceiver
import configfile
from bcsxmlrpc import xmlrpc_request_parser, xmlrpc_marshal
from customlogging import logging
logging.getLogger().setLevel(logging.DEBUG)
class ProxyClient(xmlrpc.Proxy):
def __init__(self, proxy_uri, user, timeout=30.0):
self.proxy_uri = proxy_uri
xmlrpc.Proxy.__init__(self, url=proxy_uri, user=user, connectTimeout=timeout)
#inlineCallbacks
def call_api(self, name, *args):
logging.debug(u"Calling API: %s" % name)
result = yield self.callRemote(name, *args)
proxy_pool.add(self.proxy_uri)
defer.returnValue(result)
class Request(object):
def __init__(self, method, params, deferred):
self.method = method
self.params = params
self.deferred = deferred
class ProxyServer(LineReceiver):
def dataReceived(self, data):
logging.pr(data)
params, method = xmlrpc_request_parser(data) # got method name and arguments
d = Deferred()
d.addCallbacks(self._send_reply, self._log_error)
logging.debug(u"%s%s added to queue" % (method, params))
queue.put(Request(method, params, d))
def _send_reply(self, result):
logging.ps(result)
self.sendLine(str(result))
def _log_error(self, error):
logging.error(error)
def connectionMade(self):
logging.info(u"New client connected")
def connectionLost(self, reason):
logging.info(u"Client connection lost: %s" % reason.getErrorMessage())
class ProxyServerFactory(protocol.Factory):
protocol = ProxyServer
def buildProtocol(self, addr):
return ProxyServer()
#inlineCallbacks
def _queue_execute_job():
if queue.pending and proxy_pool:
proxy = proxy_pool.pop()
request = yield queue.get()
result = yield ProxyClient(proxy, "").call_api(request.method, *list(request.params))
request.deferred.callback(result)
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Run configuration")
parser.add_argument('--config', help=u"Configuration file name/path")
config = configfile.ProxyConfig(parser.parse_args().config)
global proxy_pool
proxy_pool = set()
for proxy_server in config.servers:
proxy_pool.add(proxy_server)
global queue
queue = DeferredQueue()
lc2 = LoopingCall(_queue_execute_job)
lc2.start(1)
logging.info(u"Starting Proxy at port %s" % config.port)
reactor.listenTCP(config.port, ProxyServerFactory())
reactor.run()