How to disable output buffering with PHP and nginx

[Francis Daly]

On Mon, Oct 07, 2013 at 03:22:15PM -0400, Ben Johnson wrote:
> On 9/16/2013 1:19 PM, Ben Johnson wrote:

Hi there,

> > For whatever reason, nginx *always* buffers the output, even when I set

> > Is it possible to disable PHP output buffering completely in nginx?

Have you shown that the initial problem is on the nginx side?

I suspect it will be more interesting to people on this list if you
have a simple test case which demonstrates that it is nginx which is
buffering when you don't want it to.

Use a php script like this:

==
<?
echo "The first bit";
sleep(5);
echo "The second bit";
?>
==

Run the fastcgi server like this:

  env -i php-cgi -d cgi.fix_pathinfo=0 -q -b 9009

Use an nginx config which includes something like this:

==
  location = /php {
    fastcgi_param SCRIPT_FILENAME /usr/local/nginx/test.php;
    fastcgi_pass 127.0.0.1:9009;
  }
==

Then do something like

  tcpdump -nn -i any -A -s 0 port 9009

while also doing a

  curl -i http://127.0.0.1:8080/php

and look at the network traffic from the fastcgi server.

If you don't see a five-second gap between the two different response
packets, it is being buffered before it gets to nginx.

Now make whichever please-don't-buffer changes seem useful in the php code
and in the fastcgi server configuration. When you can see non-buffered
output getting to nginx, then you know the non-nginx side is doing what
you want. So now you can start testing nginx configuration changes;
and you can share the exact non-nginx configuration you use, so that
someone else can copy-paste it and see the same problem that you see.

(Change 127.0.0.1:9009 to be whatever remote server runs your fastcgi
server, if that makes it easier to run tcpdump.)

Good luck with it,

	f
-- 
Francis Daly        francis at daoine.org