[Twisted-Python] XML-RPC server

[Kelly Vincent]

I am quite new to Twisted and I'm having some trouble
getting my XML-RPC server to do exactly what I want. 

We have a relatively simple goal: create an XML-RPC
server that will accept a request for a score, call a
function that computes that score, and then return the
score. The two catches are that 1. the client is
actually a .NET web server rather than a Twisted
client, and 2. we could have thousands of requests
come in relatively simultaneously (though more likely
not greater than a few hundred), likely with lots of
downtime between these periods of high activity. We
are planning to create a look-up table to deal with
some of the more common calculations, but I still need
to be able to run the other calculations
non-sequentially. I know that using a Deferred object
is the normal solution, but I'm not entirely sure if
it could work here without threads. I read somewhere 
that when the function call is not from another 
Twisted application, it's not possible to use the 
Deferred object. Is this actually the case? Or would 
it work in my situation since all of the "deferring" 
would be occurring within the server itself? My 
current solution involves using threads and a Deferred

object. Is this the best way to do this? Can it be 
done without threads? If so, how and is that a better
solution than the one with threads?

Here is my sample code, which does a simple 
calculation rather than the real one I will be using. 
Both my Twisted testing client and the .NET web 
server are able to talk to this server and get the 
correct results back. 


from twisted.web import resource, server, xmlrpc
from twisted.internet import defer, threads
from twisted.python import threadable
threadable.init()

class ScoreServer(xmlrpc.XMLRPC):
    def xmlrpc_calculateScore(self,params):
        t = params[0]
        d = threads.deferToThread(self.calc,t)
        val = d.addCallback(self.handleSuccess)
        d.addErrback(self.handleFailure)
        print t, d
        return val
    def calc(self,t):
        import time
        time.sleep(t)
        result = [t,t*10]
        return result
    def handleSuccess(self,t):
        print 'succeeded', t
        return t
    def handleFailure(self):
        print 'failed miserably'
        return ['Error']
        
if __name__ == "__main__":
    from twisted.internet import reactor
    root = resource.Resource()
    root.putChild('RPC2', ScoreServer())
    reactor.listenTCP(8082, server.Site(root))
    reactor.run()