2009/3/6 Brian Sutherland <[email protected]>:
>
> Hi,
>
> I've managed to make a minimal wsgi application that shows off a
> problem we encountered in production. It looks like mod_wsgi is
> leaking the temporary files we give to it. Perhaps we are doing
> something wrong, but I couldn't find any docs against passing
> tempfile.mkstemp files to mod_wsgi. Curiously, creating the file with
> tempfile.TemporaryFile rather than tempfile.mkstemp has allowed us to
> work around the issue.
>
> Basically running ab against this application:
>
> #!/usr/bin/python
> import tempfile
> import os
>
> def application(environ, start_response):
> status = '200 OK'
> output = 'Hello World!'
>
> response_headers = [('Content-type', 'text/plain'),
> ('Content-Length', str(len(output)))]
>
> start_response(status, response_headers)
>
> # Make a temporary file and write data to it
> _, filename = tempfile.mkstemp()
This returns a file descriptor which you are assigning to '_' variable
but you aren't closing it. This means that when it is closed is at the
mercy of the Python garbage collector. They thus aren't being closed
promptly and you are running out of file descriptors.
> f = open(filename, 'wb')
> f.write(output)
> f.close()
>
> # Make a deleted read-only file to pass to mod_wsgi
> readf = open(filename, 'rb')
> os.remove(filename)
You probably want to use something like:
f, filename = tempfile.mkstemp()
f.write(output)
f.flush()
f.seek(0)
Then use 'f' as argument to file wrapper.
So, my questions about MPM and mode aren't relevant.
Graham
> wrapper = environ.get('wsgi.file_wrapper')
> return wrapper(readf)
>
> Causes these errors:
>
> [Fri Mar 06 09:50:16 2009] [error] [client 62.57.1.12] mod_wsgi
> (pid=18665): Exception occurred processing WSGI script '/etc/apache2/
> wsgi/wsgitest.wsgi'.
> [Fri Mar 06 09:50:16 2009] [error] Traceback (most recent call last):
> [Fri Mar 06 09:50:16 2009] [error] File "/etc/apache2/wsgi/
> wsgitest.wsgi", line 15, in application
> [Fri Mar 06 09:50:16 2009] [error] File "tempfile.py", line 302, in
> mkstemp
> [Fri Mar 06 09:50:16 2009] [error] File "tempfile.py", line 236, in
> _mkstemp_inner
> [Fri Mar 06 09:50:16 2009] [error] OSError: [Errno 24] Too many open
> files: '/tmp/tmp3zONgs'
>
> Because you very quickly get to the per-process file limit:
>
> load:/etc/apache2/wsgi# ls /proc/18665/fd | wc -l
> 1023
>
> We're running python 2.4.4, apache 2.2.3-4+etch6 on Debian Etch and
> have seen this with mod_wsgi 2.1 and 2.3.
>
> Many Thanks,
> Brian
>
> >
>
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"modwsgi" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/modwsgi?hl=en
-~----------~----~----~----~------~----~------~--~---
