Python – Apache2 Modpython : IOError: Write failed, client closed connection

apache-2.2djangopython

This is the error :

[Mon Mar 01 12:19:50 2010] [error] [client XXX.XXX.248.60] mod_python (pid=9528, interpreter='realpage.com', phase='PythonHandler', handler='django.core.handlers.modpython'): Application error
[Mon Mar 01 12:19:50 2010] [error] [client XXX.XXX.248.60] ServerName: 'realpage.dom'
[Mon Mar 01 12:19:50 2010] [error] [client XXX.XXX.248.60] DocumentRoot: '/htdocs'
[Mon Mar 01 12:19:50 2010] [error] [client XXX.XXX.248.60] URI: '/'
[Mon Mar 01 12:19:50 2010] [error] [client XXX.XXX.248.60] Location: '/'
[Mon Mar 01 12:19:50 2010] [error] [client XXX.XX.248.60] Directory: None
[Mon Mar 01 12:19:50 2010] [error] [client XXX.XXX.248.60] Filename: '/htdocs'
[Mon Mar 01 12:19:50 2010] [error] [client XXX.XXX.248.60] PathInfo: '/'
[Mon Mar 01 12:19:50 2010] [error] [client XXX.XXX.248.60] Traceback (most recent call last):
[Mon Mar 01 12:19:50 2010] [error] [client XXX.XXX.248.60]   File "/usr/lib/python2.5/site-packages/mod_python/importer.py", line 1537, in HandlerDispatch\n    default=default_handler, arg=req, silent=hlist.silent)
[Mon Mar 01 12:19:50 2010] [error] [client XXX.XXX.248.60]   File "/usr/lib/python2.5/site-packages/mod_python/importer.py", line 1229, in _process_target\n    result = _execute_target(config, req, object, arg)
[Mon Mar 01 12:19:50 2010] [error] [client XXX.XXX.248.60]   File "/usr/lib/python2.5/site-packages/mod_python/importer.py", line 1128, in _execute_target\n    result = object(arg)
[Mon Mar 01 12:19:50 2010] [error] [client XXX.XXX.248.60]   File "/usr/lib/python2.5/site-packages/django/core/handlers/modpython.py", line 228, in handler\n    return ModPythonHandler()(req)
[Mon Mar 01 12:19:50 2010] [error] [client XXX.XXX.248.60]   File "/usr/lib/python2.5/site-packages/django/core/handlers/modpython.py", line 220, in __call__\n    req.write(chunk)
[Mon Mar 01 12:19:50 2010] [error] [client XXX.XX.248.60] IOError: Write failed, client closed connection.

Please! I am sure you need more information in order to find the bug, please tell me what and how to get it.

The error is throwing every time!

Best Answer

As the message explains, this occurs where the handler attempts to write data back to the client after the client has closed the connection. This could occur where client user of the client pressed reload before waiting for a response. It might also occur where the handler tries to write back significantly more data than was specified by the response content length.

Related Solutions

Linux – Apache server keeps crashing regularly

I'm not saying this is what's happening but based on my own experience as a CentOS admin, it's most likely runaway apache/php processes taking down the server. I've seen this numerous times on CentOS 5. It's frustrating because there's usually not a trace of what happened in the log files. The machine just grinds to a halt due to physical memory and swap being sucked up by apache/php processes. You would think linux memory management or some daemon would jump in and say "hey stop" but it doesn't. It'll let apache grind your system to a halt.

Having said that, to see what's happening you'll need something that can monitor and log resource usage. I like to use a program called atop. Atop is a lot like the top program but it also takes a snapshot of resource usage at defined intervals. It's pretty simple to install.

wget http://www.atcomputing.nl/Tools/atop/packages/atop-1.23.tar.gz 
tar -zxvf atop-1.23.tar.gz
cd atop-1.23 && make install

Open /etc/atop/atop.daily with a text editor and change INTERVAL=600 to INTERVAL=60

Run the command /etc/atop/atop.daily from a command prompt to start it. Wait a few minutes and run atop -r /var/log/atop/atop_20091118 with the correct date of course.

Hit the t key to go forward in time and T to go back. Next time your server crashes do this and check the MEM free and SWP free lines. If you have memory problems these will be in red. Also look for numerous httpd lines under CMD. If apache/php is your problem there'll be a bunch of them.

If this is the case, I recommend looking at you're MaxClients setting in httpd.conf. If set too high, apache will gladly eat all of your memory causing your machine to crash. Apache/php can easily eat 40-50MB/process. If you multiply 40mb x MaxClients you'll get a rough idea of how much memory apache can potentially use. MaxClients usually defaults to 150 on CentOS so apache can potentially use 6GB of memory by default. This doesn't include memory your system needs for itself and other processes to run. Try setting it to a more realistic value based on the amount of memory you have like 40 if you have 2G of memory and see if that helps. Also if you have KeepAlive On, set KeepAliveTimeout to a low number like 2 or 3.

In my opinion CentOS's apache/php compilation is a real pos that should never have seen the light of day. It's buggy and crash prone. If you run a serious site, I highly recommend compiling your own version of apache/php or even using one of the newer high performance webservers like lighttpd or nginx with fgci php.

Php – Apache HTTPD: “client denied by server configuration: .htaccess” Even When .htaccess is Blank

Apparently the .htaccess wasn't being read because I didn't allow configuration overrides; if I added "AllowOverride All" to my Virtual Hosts Directory, it worked—except for mod_rewrite, due to the following error:

Options FollowSymLinks or SymLinksIfOwnerMatch is off which implies that RewriteRule directive is forbidden

After I added in Options FollowSymLinks everything worked.

Final code:

<Directory "D:/Path/To/Sites">
  Options Indexes FollowSymLinks
  AllowOverride All
  Order Deny,Allow
  Allow from all
</Directory>

Best Answer

Related Solutions

Linux – Apache server keeps crashing regularly

Php – Apache HTTPD: “client denied by server configuration: .htaccess” Even When .htaccess is Blank

Related Topic