Python prompts [Errno] broken pipe causes thread crash error

Source: Internet
Author: User
Tags curl flush http request readline socket unsupported in python

1 Error phenomena

The HTTP service implemented by Threadinghttpserver, if the client is actively disconnected before the server returns, the server side will report [Errno] broken pipe wrong and cause the processing thread to crash.

Let's take a look at an example, Python version: 2.7

Sample code

The code is as follows Copy Code

#!/usr/bin/env python
#!coding=utf-8

Import OS
Import time
Import socket
Import threading
From Basehttpserver import Httpserver, Basehttprequesthandler
From Socketserver import ThreadingMixIn

Class RequestHandler (Basehttprequesthandler):
def do_get (self):
"""
Handling GET Requests
"""
Query=self.path
Print "Query:%s thread=%s"% (query, str (threading.current_thread ())

#ret_str = "Ret_str= "
Time.sleep (5)

Try
Self.send_response (200)
Self.send_header (' Content-type ', ' text/html ')
Self.end_headers ()
Self.wfile.write (RET_STR)
Except Socket.error, E:
Print "Socket.error:Connection broke. Aborting "+ str (e)
Self.wfile._sock.close () # Close Socket
Self.wfile._sock=none
Return False

Print "Success PROD query:%s"% (query)
Return True


#多线程处理
Class Threadinghttpserver (Threadingmixin,httpserver):
Pass

if __name__ = = ' __main__ ':
Serveraddr = (', 9001)

Ser = Threadinghttpserver (Serveraddr,requesthandler)
Ser.serve_forever ()
Sys.exit (0)

Running Services
./thread_http_server_error.py

1th time Curl, waiting to return

The code is as follows Copy Code

[~] $curl-S ' http://10.232.41.142:9001/hello1′

At this point the server-side output log is as follows:

$./thread_http_server_error.py

Query:/hello1 thread=

search041142.sqa.cm4.tbsite.net–-[15/may/2014 15:02:27] "Get/hello1 http/1.1″200-

Success PROD query:/hello1

2nd time Curl, do not wait to return, CTRL +C to simulate client disconnect

The code is as follows Copy Code
[~] $curl-S ' http://10.232.41.142:9001/hello2′
[~]$ Ctrl + C

At this point the server-side output log is as follows:

Query:/hello2 thread=
search041142.sqa.cm4.tbsite.net–-[15/may/2014 15:33:10] "Get/hello2 http/1.1″200-

Socket.error:Connection broke. Aborting[errno] Broken Pipe

—————————————-

Exception happened during processing of request from (' 10.232.41.142′, 48769)

Traceback (most recent call last):

File "/home/wuzhu/tools/python_2_7_1/lib/python2.7/socketserver.py", line 582, in Process_request_thread

Self.finish_request (Request, client_address)

File "/home/wuzhu/tools/python_2_7_1/lib/python2.7/socketserver.py", line 323, in Finish_request

Self. Requesthandlerclass (Request, client_address, self)

File "/home/wuzhu/tools/python_2_7_1/lib/python2.7/socketserver.py", line 639, in __init__

Self.handle ()

File "/home/wuzhu/tools/python_2_7_1/lib/python2.7/basehttpserver.py", line 337, in handle

Self.handle_one_request ()

File "/home/wuzhu/tools/python_2_7_1/lib/python2.7/basehttpserver.py", line 326, in Handle_one_request

Self.wfile.flush () #actually Send the response if not already done.

File "/home/wuzhu/tools/python_2_7_1/lib/python2.7/socket.py", line 303, in flush

Self._sock.sendall (View[write_offset:write_offset+buffer_size])

Attributeerror: ' Nonetype ' object has no attribute ' Sendall '

—————————————-

2 Causal Analysis
"[Errno] broken pipe" The reason is relatively clear, because the client in the server before the return of the active disconnect, so the server on the return write socket received sigpipe error. Although exceptions are also processed in our programs, close the handler Wfile._sock object, but the member functions of the Basehttprequesthandler class in Python's library basehttpserver.py handle _one_request will still call Wfile.flush directly, without determining if wfile is close.

The code is as follows Copy Code

def handle_one_request (self):
"" "Handle a single HTTP request.

You are normally don ' t need to override this method; The class
__doc__ string for information on I to handle specific HTTP
Commands such as Get and POST.

"""
Try
Self.raw_requestline = Self.rfile.readline (65537)
If Len (self.raw_requestline) > 65536:
Self.requestline = ' '
self.request_version = ' '
Self.command = ' '
Self.send_error (414)
Return
If not self.raw_requestline:
Self.close_connection = 1
Return
If not self.parse_request ():
# An error code has been sent, just exit
Return
Mname = ' Do_ ' + self.command
If not hasattr (self, mname):
Self.send_error (501, "Unsupported Method (%r)"% Self.command)
Return
method = GetAttr (self, mname)
Method ()
#没有判断 Wfile is already close, call flush directly ()
Self.wfile.flush () #actually Send the response if not already done.
Except Socket.timeout, E:
#a Read or a write timed out. Discard this connection
Self.log_error ("Request timed out:%r", E)
Self.close_connection = 1
Return

3 Solutions
As long as you overload the member function Handle_one_reques () of its base class Basehttprequesthandler in RequestHandler, precede the call to Wfile.flush () plus whether the wfile is close.

The code is as follows Copy Code

#!/usr/bin/env python
#!coding=utf-8

Import OS
Import time
Import socket
Import threading
From Basehttpserver import Httpserver, Basehttprequesthandler
From Socketserver import ThreadingMixIn



Class RequestHandler (Basehttprequesthandler):

def handle_one_request (self):
"" "Handle a single HTTP request.

You are normally don ' t need to override this method; The class
__doc__ string for information on I to handle specific HTTP
Commands such as Get and POST.

"""
Try
Self.raw_requestline = Self.rfile.readline (65537)
If Len (self.raw_requestline) > 65536:
Self.requestline = ' '
self.request_version = ' '
Self.command = ' '
Self.send_error (414)
Return
If not self.raw_requestline:
Self.close_connection = 1
Return
If not self.parse_request ():
# An error code has been sent, just exit
Return
Mname = ' Do_ ' + self.command
If not hasattr (self, mname):
Self.send_error (501, "Unsupported Method (%r)"% Self.command)
Return
method = GetAttr (self, mname)
Print "Before Call Do_get"
Method ()
#增加 Debug Info and Wfile to determine if close
Print "After call Do_get"
If not self.wfile.closed:
Self.wfile.flush () #actually Send the response if not already done.
Print "After Wfile.flush ()"
Except Socket.timeout, E:
#a Read or a write timed out. Discard this connection
Self.log_error ("Request timed out:%r", E)
Self.close_connection = 1
Return

def do_get (self):
"""
Handling GET Requests
"""
Query=self.path
Print "Query:%s thread=%s"% (query, str (threading.current_thread ())

Ret_str= "
Time.sleep (5)

Try
Self.send_response (200)
Self.send_header (' Content-type ', ' text/html ')
Self.end_headers ()
Self.wfile.write (RET_STR)
Except Socket.error, E:
Print "Socket.error:Connection broke. Aborting "+ str (e)
Self.wfile._sock.close ()
Self.wfile._sock=none
Return False

Print "Success PROD query:%s"% (query)
Return True

#多线程处理
Class Threadinghttpserver (Threadingmixin,httpserver):
Pass

if __name__ = = ' __main__ ':
Serveraddr = (', 9001)

Ser = Threadinghttpserver (Serveraddr,requesthandler)
Ser.serve_forever ()
Sys.exit (0)

Running Services
./thread_http_server.py
Curl, do not wait to return, CTRL +C to simulate client disconnect
[~] $curl-S ' Http://10.232.41.142:9001/hello2 '
[~]$ Ctrl + C

At this point the server-side output log is as follows:

The code is as follows Copy Code

$./thread_http_server.pybefore Call Do_get

Query:/hello2 thread=<thread (Thread-1, started 1103210816) >

Search041142.sqa.cm4.tbsite.net--[15/may/2014 15:54:09] "Get/hello2 http/1.1" 200-

Socket.error:Connection broke. Aborting[errno] Broken Pipe

After the call Do_get

After Wfile.flush ()

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.