在 Tornado 中制作异步 xmlrpc（客户端调用）

Question

我需要对 Tornado 中的 Cobbler 服务器进行异步 XML-RPC（客户端调用），例如：

cobbler_connection = xmlrpclib.Server("http://my_cobbler_server")

...
profile = yield gen.Task(cobbler_connection.get_profile, profile_name)
...

现在我正在使用 xmlrpclib，它似乎不会进行异步客户端调用，因此它最终会阻止 Tornado（或者我听说）。一般来说，我是 Tornado 和异步编程的新手（但请不要给我任何指向某些说明或初学者指南的链接）。我试过谷歌搜索，但我无法清楚地了解我需要对 xmlrpclib 进行哪些更改，以便可以使这些调用异步。任何指针将不胜感激。提前致谢。

Answer 1

检查Twisted 是否支持各种操作通常是个好主意，因为它可以使用tornado.platform.twisted 与Tornado 结合使用。对于 XML-RPC 有如下代码：http://twistedmatrix.com/documents/13.0.0/web/howto/xmlrpc.html 一个简单的例子：

import tornado.httpserver
import tornado.ioloop
import tornado.web
import tornado.platform.twisted

tornado.platform.twisted.install()

from twisted.web.xmlrpc import Proxy
from twisted.internet import reactor

proxy = Proxy('http://advogato.org/XMLRPC')

from tornado.options import define, options
define("port", default=8000, help="run on the given port", type=int)

class IndexHandler(tornado.web.RequestHandler):
    def printValue(self, value):
        self.write(repr(value))
        self.finish()

    def printError(self, error):
        self.write('error: %s' % error) 
        self.finish()

    @tornado.web.asynchronous
    def get(self):
        proxy.callRemote('test.sumprod', 3, 5).addCallbacks(self.printValue, self.printError)

if __name__ == "__main__":
    tornado.options.parse_command_line()
    app = tornado.web.Application(handlers=[(r"/", IndexHandler)])
    http_server = tornado.httpserver.HTTPServer(app)
    http_server.listen(options.port)
    tornado.ioloop.IOLoop.instance().start()

基准测试：

$ ab -n 1000 -c 5 http://localhost:8000/
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking localhost (be patient)
Completed 100 requests
Completed 200 requests
Completed 300 requests
Completed 400 requests
Completed 500 requests
Completed 600 requests
Completed 700 requests
Completed 800 requests
Completed 900 requests
Completed 1000 requests
Finished 1000 requests


Server Software:        TornadoServer/3.0.1
Server Hostname:        localhost
Server Port:            8000

Document Path:          /
Document Length:        7 bytes

Concurrency Level:      5
Time taken for tests:   76.529 seconds
Complete requests:      1000
Failed requests:        0
Write errors:           0
Total transferred:      201000 bytes
HTML transferred:       7000 bytes
Requests per second:    13.07 [#/sec] (mean)
Time per request:       382.646 [ms] (mean)
Time per request:       76.529 [ms] (mean, across all concurrent requests)
Transfer rate:          2.56 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.0      0       0
Processing:   302  382 498.9    308    5318
Waiting:      302  382 498.9    308    5318
Total:        302  382 498.9    308    5318

Percentage of the requests served within a certain time (ms)
  50%    308
  66%    310
  75%    311
  80%    313
  90%    320
  95%    334
  98%   1310
  99%   3309
 100%   5318 (longest request)

直接使用xmlrpclib进行比较：

import tornado.httpserver
import tornado.ioloop
import tornado.web

import xmlrpclib    

server = xmlrpclib.ServerProxy('http://advogato.org/XMLRPC')

from tornado.options import define, options
define("port", default=8000, help="run on the given port", type=int)

class IndexHandler(tornado.web.RequestHandler):
    def get(self):
        self.write(repr(server.test.sumprod(3, 5)))

if __name__ == "__main__":
    tornado.options.parse_command_line()
    app = tornado.web.Application(handlers=[(r"/", IndexHandler)])
    http_server = tornado.httpserver.HTTPServer(app)
    http_server.listen(options.port)
    tornado.ioloop.IOLoop.instance().start()

基准测试：

$  ab -n 1000 -c 5 http://localhost:8000/
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking localhost (be patient)
Completed 100 requests
Completed 200 requests
Completed 300 requests
Completed 400 requests
Completed 500 requests
Completed 600 requests
Completed 700 requests
Completed 800 requests
Completed 900 requests
Completed 1000 requests
Finished 1000 requests


Server Software:        TornadoServer/3.0.1
Server Hostname:        localhost
Server Port:            8000

Document Path:          /
Document Length:        7 bytes

Concurrency Level:      5
Time taken for tests:   325.538 seconds
Complete requests:      1000
Failed requests:        0
Write errors:           0
Total transferred:      201000 bytes
HTML transferred:       7000 bytes
Requests per second:    3.07 [#/sec] (mean)
Time per request:       1627.690 [ms] (mean)
Time per request:       325.538 [ms] (mean, across all concurrent requests)
Transfer rate:          0.60 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.0      0       0
Processing:   305 1625 484.5   1532    4537
Waiting:      305 1624 484.5   1532    4537
Total:        305 1625 484.5   1532    4537

Percentage of the requests served within a certain time (ms)
  50%   1532
  66%   1535
  75%   1537
  80%   1539
  90%   1547
  95%   1984
  98%   4524
  99%   4533
 100%   4537 (longest request)

更糟糕。