Serving large files ( with high loads ) in Django

Your opening of the image loads it in memory and this is what causes the increase in load under heavy use. As posted by Martin the real solution is to serve the file directly.

Here is another approach, which will stream your file in chunks without loading it in memory.

import osimport mimetypesfrom django.http import StreamingHttpResponsefrom django.core.servers.basehttp import FileWrapperdef download_file(request):   the_file = '/some/file/name.png'   filename = os.path.basename(the_file)   chunk_size = 8192   response = StreamingHttpResponse(FileWrapper(open(the_file, 'rb'), chunk_size),                           content_type=mimetypes.guess_type(the_file)[0])   response['Content-Length'] = os.path.getsize(the_file)       response['Content-Disposition'] = "attachment; filename=%s" % filename   return response

You can use the 'sendfile' method as described in this answer.

Practically you need this (c&p):

response = HttpResponse(mimetype='application/force-download')response['Content-Disposition'] = 'attachment; filename=%s' % smart_str(file_name)response['X-Sendfile'] = smart_str(path_to_file)# It's usually a good idea to set the 'Content-Length' header too.# You can also set any other required headers: Cache-Control, etc.return response

This requires mod_xsendfile (which is also supported by nginx or lighty)

FileWrapper won't work when GZipMiddleware is installed (Django 1.4 and below):https://code.djangoproject.com/ticket/6027

If using GZipMiddleware, a practical solution is to write a subclass of FileWrapper like so:

from wsgiref.util import FileWrapperclass FixedFileWrapper(FileWrapper):    def __iter__(self):        self.filelike.seek(0)        return selfimport mimetypes, osmy_file = '/some/path/xy.ext'response = HttpResponse(FixedFileWrapper(open(my_file, 'rb')), content_type=mimetypes.guess_type(my_file)[0])response['Content-Length'] = os.path.getsize(my_file)response['Content-Disposition'] = "attachment; filename=%s" % os.path.basename(my_file)return response

As of Python 2.5, there's no need to import FileWrapper from Django.