How do I stop Tornado web server

import tornado.ioloop
import tornado.web

class MainHandler(tornado.web.RequestHandler):
    def get(self):
        self.write("Hello, world")

application = tornado.web.Application([
    (r"/", MainHandler),
])

if __name__ == "__main__":
    application.listen(8888)
    tornado.ioloop.IOLoop.instance().start()

To use asynchronous methods from otherwise-synchronous code (such as
unit tests), you can start and stop the event loop like this:
  ioloop = IOLoop()
  async_method(ioloop=ioloop, callback=ioloop.stop)
  ioloop.start()
ioloop.start() will return after async_method has run its callback,
whether that callback was invoked before or after ioloop.start.

class Server:
    def __init__(self, port=8888):
        self.application = tornado.web.Application([ (r"/", Handler) ])

        def server_thread(application, port):
            http_server = tornado.httpserver.HTTPServer(application)
            http_server.listen(port)
            tornado.ioloop.IOLoop.instance().start()

        self.process = Process(target=server_thread,
                               args=(self.application, port,))

    def start(self):
        self.process.start()

    def stop(self):
        ioloop = tornado.ioloop.IOLoop.instance()
        ioloop.add_callback(ioloop.stop)

def setup_method(self, _function):
    self.server = Server()
    self.server.start()
    time.sleep(0.5)  # Wait for web server to start

def teardown_method(self, _function):
    self.kstore.stop()
    time.sleep(0.5)

import tornado.ioloop, tornado.web

class Handler(tornado.web.RequestHandler):
    def get(self):
        self.write("Hello, world")

application = tornado.web.Application([ (r"/", Handler) ])

def startTornado():
    application.listen(8888)
    tornado.ioloop.IOLoop.instance().start()

def stopTornado():
    tornado.ioloop.IOLoop.instance().stop()

if __name__ == "__main__":
    import time, threading
    threading.Thread(target=startTornado).start()
    print "Your web server will self destruct in 2 minutes"
    time.sleep(120)
    stopTornado()