Only 64k sent when the first upstream failed in fastcgi_pass

[Valentin V. Bartenev]

On Tuesday 17 June 2014 23:50:19 Jing Ye wrote:
> Hello all,
> 
> I have encountered the following possible bug in Nginx when using the
> fastcgi_pass directive to put a file larger than 64k. I’m not sure if this
> is a bug or I missed something in the config file.
> 
> My nginx version is 1.5.12, and the problem remains when i switched to the
> newest 1.7.2.
> 
> 
> Here is my nginx.conf file,
> 
>     upstream *api.php.com <http://api.php.com>* {
>             server 127.0.0.1:9902 max_fails=3 fail_timeout=30s;
>             server 127.0.0.1:9901 max_fails=3 fail_timeout=30s;
>     }
>     server {
>         listen       8080;
>         server_name  localhost;
>         location ~ \.php$ {
>             root           html;
>             fastcgi_pass   *api.php.com <http://api.php.com>*;
>             fastcgi_param  SCRIPT_FILENAME
> /usr/local/nginx/html/$fastcgi_script_name;
>             fastcgi_index  index.php;
>             include        fastcgi_params;
>         }
> 
> 
> 
> And the index.php file,
> 
> <?php
> /* simplify get the request body and print its length. */
> $raw_post_data = file_get_contents('php://input', 'r');
> print(strlen($raw_post_data));
> sleep(3);               /* waiting for the server to be reset after 1
> second  */
> ?>
> 
> 
[..]
> 
> The response status is 200 OK, but only 65536 bytes(64k) received.
> Is this a bug or have i made something wrong in the config file?
> I’m really confusing and hope if someone could help me figure it out.
> 

In the FastCGI protocol the data is transferred using "records".  The maximum
size of one record is 64k.  So you're probably getting only the first record 
by calling file_get_contents() once.

  wbr, Valentin V. Bartenev