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Tornado“错误：[Errno 24] 文件打开过多”问题

5 投票
1 回答
9106 浏览
提问于 2025-04-17 06:43

我之前用过Tornado很多次，但这是我第一次遇到这种错误。我正在做一个非常简单的URL缩短器。URL是由另一个应用程序放入数据库的，这个应用程序只是从MongoDB数据库中读取URL并进行重定向。在我写完基本代码后，我对它进行了一个简单的“Siege”测试，运行了大约30秒（使用命令siege -c 64 -t 5m -r 1 http://example.com/MKy，同时有4个应用线程），结果开始收到500错误响应。查看错误日志时，我发现了这个信息：

ERROR:root:500 GET /MKy (127.0.0.1) 2.05ms
ERROR:root:Exception in I/O handler for fd 4
Traceback (most recent call last):
  File "/opt/python2.7/lib/python2.7/site-packages/tornado-2.1-py2.7.egg/tornado/ioloop.py", line 309, in start
  File "/opt/python2.7/lib/python2.7/site-packages/tornado-2.1-py2.7.egg/tornado/netutil.py", line 314, in accept_handler
  File "/opt/python2.7/lib/python2.7/socket.py", line 200, in accept
error: [Errno 24] Too many open files
ERROR:root:Uncaught exception GET /MKy (127.0.0.1)
HTTPRequest(protocol='http', host='shortener', method='GET', uri='/MKy', version='HTTP/1.0', remote_ip='127.0.0.1', body='', headers={'Host': 'shortener', 'Accept-Encoding': 'gzip', 'X-Real-Ip': '94.23.155.32', 'X-Forwarded-For': '94.23.155.32', 'Connection': 'close', 'Accept': '*/*', 'User-Agent': 'JoeDog/1.00 [en] (X11; I; Siege 2.66)'})
Traceback (most recent call last):
  File "/opt/python2.7/lib/python2.7/site-packages/tornado-2.1-py2.7.egg/tornado/web.py", line 1040, in wrapper
  File "main.py", line 58, in get
  File "main.py", line 21, in dbmongo
  File "/opt/python2.7/lib/python2.7/site-packages/apymongo-0.0.1-py2.7-linux-x86_64.egg/apymongo/connection.py", line 349, in __init__
  File "/opt/python2.7/lib/python2.7/site-packages/apymongo-0.0.1-py2.7-linux-x86_64.egg/apymongo/connection.py", line 510, in __find_master
  File "/opt/python2.7/lib/python2.7/site-packages/apymongo-0.0.1-py2.7-linux-x86_64.egg/apymongo/connection.py", line 516, in __try_node
  File "/opt/python2.7/lib/python2.7/site-packages/apymongo-0.0.1-py2.7-linux-x86_64.egg/apymongo/database.py", line 301, in command
  File "/opt/python2.7/lib/python2.7/site-packages/apymongo-0.0.1-py2.7-linux-x86_64.egg/apymongo/collection.py", line 441, in find_one
  File "/opt/python2.7/lib/python2.7/site-packages/apymongo-0.0.1-py2.7-linux-x86_64.egg/apymongo/cursor.py", line 539, in loop
  File "/opt/python2.7/lib/python2.7/site-packages/apymongo-0.0.1-py2.7-linux-x86_64.egg/apymongo/cursor.py", line 560, in _refresh
  File "/opt/python2.7/lib/python2.7/site-packages/apymongo-0.0.1-py2.7-linux-x86_64.egg/apymongo/cursor.py", line 620, in __send_message
  File "/opt/python2.7/lib/python2.7/site-packages/apymongo-0.0.1-py2.7-linux-x86_64.egg/apymongo/connection.py", line 735, in _send_message_with_response
  File "/opt/python2.7/lib/python2.7/site-packages/apymongo-0.0.1-py2.7-linux-x86_64.egg/apymongo/connection.py", line 591, in __stream
  File "/opt/python2.7/lib/python2.7/site-packages/apymongo-0.0.1-py2.7-linux-x86_64.egg/apymongo/connection.py", line 200, in get_stream
  File "/opt/python2.7/lib/python2.7/site-packages/apymongo-0.0.1-py2.7-linux-x86_64.egg/apymongo/connection.py", line 559, in __connect
AutoReconnect: could not connect to [('127.0.0.1', 27017)]

重要提示（我想这很重要）；

错误：[Errno 24] 打开的文件太多了

代码；（非常简单）

import tornado.ioloop
import tornado.web
import tornado.escape
import apymongo
import time
import sys

#Useful stuff (Connect to Mongo)
class setup(tornado.web.RequestHandler):
    def dbmongo(self):
        if not hasattr(self, '_dbmongo'):
            self._dbmongo = apymongo.Connection("127.0.0.1", 27017)
        return self._dbmongo
        

#Basic method to lookup URLs from Mongo and redirect accordingly
class expand(setup):
    @tornado.web.asynchronous
    def get(self, url):
        self.mongo = self.dbmongo()
        
        #Lookup the URL
        cursor = self.mongo.rmgshortlinks.links.find_one({'short':url}, self.direct)
    
    def direct(self, response):
        if response == None:
            self.send_error(404)
            self.finish()
            return
        
        link = tornado.escape.url_unescape(response['long'])
        
        #Bounce the client
        self.write("<!DOCTYPE html><html><head><meta charset=\"UTF-8\" /><meta http-equiv=\"refresh\" content=\"0;URL="+link+"\"</head><body><a href=\""+link+"\">Click Here</a></body></html>")
        self.finish();


#Define the URL routes
application = tornado.web.Application([
    (r"/([a-zA-Z0-9]+)", expand)
])

#Start the server
if __name__ == "__main__":
    listening_port = int(sys.argv[1])
    
    if listening_port > 0:
        application.listen(listening_port)
        tornado.ioloop.IOLoop.instance().start()
    else:
        sys.stderr.write("No port specified!")

我使用的开发服务器有8个核心和64GB内存，运行的是RedHat Enterprise Linux 5和Python 2.6。我以前从未在Tornado/Async Mongo应用程序中遇到过这些问题。

可能有用的信息；

[root@puma ~]# ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 31374
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 31374
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

（打开的文件限制设置为1024，但我觉得这应该足够了）

Tornado/Apymongo是不是没有正确关闭连接？这些应用程序在NGINX后面，但是通过HTTP连接的，Apymongo应该是通过TCP连接，但可能使用的是套接字。即便如此，它应该是共享/池化连接的，对吧？

编辑

按照建议，我把应用程序移到了我们的一个测试服务器上，那个服务器的最大打开文件限制是61440，但在运行Siege大约30秒后还是出现了同样的错误。

mongodb 错误处理 http请求 异步编程 连接池 服务器性能 tornado 文件打开限制

1 个回答

4

很简单，每次请求都会创建一个新的RequestHandler对象。这意味着你保存的缓存对象是在RequestHandler（比如expand）对象上。

如果你在dbmongo(...)函数里加一句简单的“print 'CREATED!'”，你会发现每次GET请求都会创建一个新的对象。

你需要做的是把处理器附加到类对象上，或者根据需要使用一个“全局”变量，但最好的方法是把它放在Tornado应用对象上。

简单来说：

class setup(tornado.web.RequestHandler):
    @classmethod
    def dbmongo(cls):
        if not hasattr(cls, '_dbmongo'):
            cls._dbmongo = apymongo.Connection("127.0.0.1", 27017)
        return cls._dbmongo

第二种方法就是在你的文件里把它设为全局变量：

dbmongo_connection = None
def dbmongo():
    if not dbmongo_connection:
        dbmongo_connection = apymongo.Connection("127.0.0.1", 27017)
    return dbmongo_connection

这两种方法都有一个共同的问题，就是如果你有很多类想要使用数据库连接，分享起来会比较困难。因为数据库是一个共享的资源，你可能希望在整个应用中只用一个。

class MongoMixin(object):
    def mongodb(self):
        if not hasattr(self.application, 'mongodb'):
            self.application.mongodb = apymongo.Connection(self.application.settings.get("mongohost", "127.0.0.1"), 27017)
        return self.application.mongodb

class expand(tornado.web.RequestHandler, MongoMixin):
    def get(self):
       db = self.mongodb()
回答于 2025-04-17 由 Python大师
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