无法在多个进程中运行:IOLoop实例已初始化.在调用start_processes()之前,不能调用IOLoop.instance()

Question

我正在尝试在Tornado中运行多个进程,我尝试了在这个线程上提出的建议:运行多个龙卷风进程

但错误并没有消失.这是服务器文件.

server.py

import os
import sys
import tornado
#import pymongo

from tornado import ioloop, web, httpserver, websocket
from tornado.options import options

#Loading default setting files
import settings


#Motorengine - ODM for mongodb
#from motorengine import connect

app = tornado.web.Application(handlers=[
  (r'/', MainHandler),
  (r'/ws', WSHandler),
  (r'/public/(.*)', tornado.web.StaticFileHandler, {'path': options.public_path})],
  template_path=os.path.join(os.path.dirname(__file__), "app/templates"),
  static_path= options.static_path,
  autoreload=True,
  #images=os.path.join(os.path.dirname(__file__), "images"),
  debug=False)

if __name__ == '__main__':
   #read settings from commandline
    options.parse_command_line()
    server = tornado.httpserver.HTTPServer(app, max_buffer_size=1024*1024*201)
    server.bind(options.port)
    # autodetect cpu cores and fork one process per core
    server.start(0)

    #app.listen(options.port,xheaders=True)
    try:
        ioloop = tornado.ioloop.IOLoop.instance()
        #connect("attmlplatform", host="localhost", port=27017, io_loop=ioloop)
        print("Connected to database..")
        ioloop.start()
        print ('Server running on http://localhost:{}'.format(options.port))

    except KeyboardInterrupt:
        tornado.ioloop.IOLoop.instance().stop()

我已根据预期可能触发实例注释掉'connect'导入,而我根本没有连接到数据库.这只是试图让服务器启动.

这是整个跟踪:

  File "server.py", line 52, in <module>
    server.start(0)
  File "/home/vagrant/anaconda3/envs/py34/lib/python3.4/site-packages/tornado/tcpserver.py", line 200, in start
    process.fork_processes(num_processes)
  File "/home/vagrant/anaconda3/envs/py34/lib/python3.4/site-packages/tornado/process.py", line 126, in fork_processes
    raise RuntimeError("Cannot run in multiple processes: IOLoop instance "
RuntimeError: Cannot run in multiple processes: IOLoop instance has already been initialized. You cannot call IOLoop.instance() before calling start_processes()

任何建议非常感谢!谢谢!

Answer 1

autoreload与多进程模式不兼容.当autoreload启用你必须只运行一个进程.