Python龙卷风打开文件太多Ssl

Question

If i have many connection on my tornado server, i se error on log

Exception in callback (<socket._socketobject object at 0x7f0b9053e3d0>, <function null_wrapper at 0x7f0b9054c140>)
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/tornado/ioloop.py", line 888, in start
    handler_func(fd_obj, events)
  File "/usr/local/lib/python2.7/dist-packages/tornado/stack_context.py", line 277, in null_wrapper
    return fn(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/tornado/netutil.py", line 276, in accept_handler
    callback(connection, address)
  File "/usr/local/lib/python2.7/dist-packages/tornado/tcpserver.py", line 264, in _handle_connection
  File "/usr/local/lib/python2.7/dist-packages/tornado/netutil.py", line 517, in ssl_wrap_socket
    context = ssl_options_to_context(ssl_options)
  File "/usr/local/lib/python2.7/dist-packages/tornado/netutil.py", line 494, in ssl_options_to_context
    context.load_cert_chain(ssl_options['certfile'], ssl_options.get('keyfile', None))
IOError: [Errno 24] Too many open files

and disconnect my client. Tornado open ssl certificate file on ewery connect?

Tornado app

class VastWebSocket(tornado.websocket.WebSocketHandler):
connections = set()
current_connect = 0
current_user = 0
status_play_vast = False

def open(self):
    c = Connection()
    c.connection = self

VastWebSocket.connections.add(c)
self.current_connect = c

def on_message(self, msg):

data = json.loads(msg)

app_log.info("on message = " + msg)

if not 'status' in data:
  return

if data["status"] == "start_vast":
  VastWebSocket.status_play_vast = True

if data["status"] == "end_vast":
  VastWebSocket.status_play_vast = False

app_log.info("status_play_vast = " + str(VastWebSocket.status_play_vast))

if data["status"] == "get_status_vast":
  self.current_connect.connection.write_message({"status": VastWebSocket.status_play_vast})
  return

for conn in self.connections:
        conn.connection.write_message(msg)


def on_close(self):
if self.current_connect <> 0:
  VastWebSocket.connections.remove(self.current_connect)


def check_origin(self, origin):
return True

Start tornado server from django command

class Command(BaseCommand):
    help = 'Starts the Tornado application for message handling.'

def add_arguments(self, parser):
    parser.add_argument('port_number', nargs='+', type=int)

def sig_handler(self, sig, frame):
    """Catch signal and init callback"""
    tornado.ioloop.IOLoop.instance().add_callback(self.shutdown)

def shutdown(self):
    """Stop server and add callback to stop i/o loop"""
    self.http_server.stop()

    io_loop = tornado.ioloop.IOLoop.instance()
    io_loop.add_timeout(time.time() + 2, io_loop.stop)

def handle(self, *args, **options):
    if "port_number" in options:
        try:
            port = int(options["port_number"][0])
        except ValueError:
            raise CommandError('Invalid port number specified')
    else:
        port = 8030

    ssl_ctx = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH)
    ssl_ctx.load_cert_chain(os.path.join("/www/cert/", "rumma.crt"),
            os.path.join("/www/cert/", "rumma.key"))

    self.http_server = tornado.httpserver.HTTPServer(application, ssl_options = ssl_ctx)


    self.http_server.bind(port, address="0.0.0.0")
    self.http_server.start(1)
    # Init signals handler
    signal.signal(signal.SIGTERM, self.sig_handler)

    # This will also catch KeyboardInterrupt exception
    signal.signal(signal.SIGINT, self.sig_handler)

    tornado.ioloop.IOLoop.instance().start()

Why his open many file, in my mind need open ssl in start server and all. Stackoverflow asks more info, but in top, all info all need.

Answer 1

Your code seems to run multiple process or thread that all accessing to the ssl keyfile directly. Linux default ulimit is quick low and this error then occurs.

You can check the current setting with:

$ ulimit -a

The quick and dirty solution is to increase this value:

$ ulimit -n <new_value>

Even unlimited is accepted with the -n option.

Note: You can permanently set the value the app user .bashrc file.

In both case you'll need to log out then log in for the change to take effect.

But modifying this value is a bit dirty because it's a global value for a given user environment.

The harder but cleaner solution is to find a way to load the content of the file in memory when your app load and make the loaded value/variable accessible for all processes.