Nginx connection reset, response from uWsgi lost

Question

I have a django app hosted via Nginx and uWsgi. In a certain very simple request, I get different behaviour for GET and POST, which should not be the case.

The uWsgi daemon log:

[pid: 32454|app: 0|req: 5/17] 127.0.0.1 () {36 vars in 636 bytes} [Tue Oct 19 11:18:36 2010] POST /buy/76d4f520ae82e1dfd35564aed64a885b/a_2/10/ => generated 80 bytes in 3 msecs (HTTP/1.0 440) 1 headers in 76 bytes (0 async switches on async core 0)
[pid: 32455|app: 0|req: 5/18] 127.0.0.1 () {32 vars in 521 bytes} [Tue Oct 19 11:18:50 2010] GET /buy/76d4f520ae82e1dfd35564aed64a885b/a_2/10/ => generated 80 bytes in 3 msecs (HTTP/1.0 440) 1 headers in 76 bytes (0 async switches on async core 0)

The Nginx accesslog:

127.0.0.1 - - [19/Oct/2010:18:18:36 +0200] "POST /buy/76d4f520ae82e1dfd35564aed64a885b/a_2/10/ HTTP/1.0" 440 0 "-" "curl/7.19.5 (i486-pc-linux-gnu) libcurl/7.19.5 OpenSSL/0.9.8g zlib/1.2.3.3 libidn/1.15"
127.0.0.1 - - [19/Oct/2010:18:18:50 +0200] "GET /buy/76d4f520ae82e1dfd35564aed64a885b/a_2/10/ HTTP/1.0" 440 80 "-" "curl/7.19.5 (i486-pc-linux-gnu) libcurl/7.19.5 OpenSSL/0.9.8g zlib/1.2.3.3 libidn/1.15"

The Nginx errorlog:

2010/10/19 18:18:36 [error] 4615#0: *5 readv() failed (104: Connection reset by peer) while reading upstream, client: 127.0.0.1, server: localhost, request: "POST /buy/76d4f520ae82e1dfd35564aed64a885b/a_2/10/ HTTP/1.0", upstream: "uwsgi://unix:sock/uwsgi.sock:", host: "localhost:9201"

In essence, Nginx somewhere loses the response if I use POST, not so if I use GET.

Anybody knows something about that?

Answer 1

After a lucky find in further research (http://answerpot.com/showthread.php?577619-Several%20Bugs/Page2) I found something that helped...

Supplying the uwsgi_pass_request_body off; parameter in the Nginx conf resolves this problem...

Answer 2

Pass --post-buffering 1 to uwsgi

This will automatically buffer all the http body > 1 byte

The problem is raised by the way nginx manages upstream disconnections

Answer 3

I am facing the same issues. I tried all solutions above, but they were not working. Ignoring the response body in my case is simply not an option.

Apparently it is a bug with nginx and uwsgi when dealing with POST requests whose response is smaller than 4052 bytes

What solved it for me was adding "--pep3333-input" to the parameter list of uwsgi. After that all POSTs are returned correctly.

Versions of nginx/uwsgi I'm using:

$ nginx -V
nginx: nginx version: nginx/0.9.6

$ uwsgi --version
uWSGI 0.9.7

Answer 4

I hit the same issue, but on my case I can't disable "uwsgi_pass_request_body" as most times (but not always) my app do need the POST data.

This is the workaround I found, while this issue is not fixed in uwsgi: http://permalink.gmane.org/gmane.comp.python.wsgi.uwsgi.general/813

import django.core.handlers.wsgi
class ForcePostHandler(django.core.handlers.wsgi.WSGIHandler):
    """Workaround for: http://lists.unbit.it/pipermail/uwsgi/2011-February/001395.html
    """
    def get_response(self, request):
        request.POST # force reading of POST data
        return super(ForcePostHandler, self).get_response(request)

application = ForcePostHandler()