Django, apache, mod_wsgi - Error: Premature end of script headers

Question

Apache logs in mode debug:

[Tue Dec 21 11:36:33 2010] [info] [client 1.53.149.114] mod_wsgi (pid=24831, process=\'mysite\', application=\'mysite.com|\'): Loading         


        

Answer 1

Finally, I found the solution. It's a problem of Multiple Python Versions: http://code.google.com/p/modwsgi/wiki/InstallationIssues#Multiple_Python_Versions.

Thanks all! :P

Answer 2

I had a similar problem on django,apache2,mod_wsgi,python2.6 installed on a virtual machine. I solved the problem incerasing the ram assigned to the virtual machine.

I hope this will help.

Answer 3

Try to delete this

WSGISocketPrefix /tmp/wsgi

And this

WSGIDaemonProcess mysite processes=5 threads=25
WSGIProcessGroup mysite

On my server it works.

Answer 4

The daemon process crashed. See comments in the mod_wsgi FAQ about what causes crashes:

http://code.google.com/p/modwsgi/wiki/FrequentlyAskedQuestions

and follow links there.

Ultimately the cause can be many things, including loading incompatible mod_python at same time, using Python C extension module that doesn't work with sub interpreters, incompatible shared library versions used by Apache and/or extension modules in PHP etc.

Answer 5

my same issue was resolved like this: remove cgi configure that was added by me someday:

AddHandler cgi-script .py

Answer 6

I am getting this same error, and while the underlying cause may be the multiple python versions, I have found that it is happening because of hung queries from Django to my MySQL server. If I run a

show processlist;

at the MySQL prompt, I see that queries are backing up in the queue. If I kill the query at the top, all other open processes immediately complete and my site comes back to life.

Hope this helps someone else. You can also run

show full processlist;

to see the exact query. In my case, it was a django select_related query that created tons of INNER JOIN clauses in the query.

See: http://dev.mysql.com/doc/refman/5.1/en/show-processlist.html