Nginx proxy truncates large file downloads to 1.1G

[Duane Mulder]

Hello All:

So nginx so far has been running great. Today however I discovered that
when downloading a file larger than 1G (ie 1.5G)  it will always fail
leaving the client with a file of 1.1G and an incomplete download. If I
point directly to the webserver the download completes properly. 
Downloading over a slow or local or fast link does not change the
problem. Its the file size that appears to be causing the issue. Any
size of file download which is under 1G works and downloads with no issues.

I suspect its some issue with proxy buffering however I have not been
able to come up with the secret sauce to make it work.  Below is the
last iteration of my config which still truncates large file downloads.
The boxes that nginx is running on are a dedicated dual core dual Xeon
3Ghz with 8G of ram.

Also there does not seem to be anything in the error logs when this occurs.

Regards,
Duane

The files
user  nginx;
worker_processes  4;
events {
    worker_connections  1024;
    use epoll;
    multi_accept on;
}

http { #http
       include       mime.types;
       default_type  application/octet-stream;
        gzip            on;
        gzip_http_version 1.0;
        gzip_comp_level 2;
        gzip_proxied any;
        gzip_types      text/plain text/css application/x-javascript
text/xml application/xml application/xml+rss text/javascript;
        gzip_buffers 16 8k;
        #disable for IE 6
        gzip_disable "MSIE [1-6]\.(?!.*SV1)";
# POST size limit
    # Set File upload limit at 2G
    client_max_body_size 2000M;
    sendfile        on;
    keepalive_timeout  65;


server { #server80
  listen  192.168.1.231:80 ;
  server_name  x.x.com;

  ##Blocked IP address message
  error_page 403 = http://x.y.com/monitor/x_403.html;

     ### Add SSL specific settings here ###
        keepalive_timeout    240;
        access_log  /nginx/cust-SSL/logs/access.log;
        error_log /nginx/cust-SSL/logs/error.log;

    location /nginx_status {
          stub_status on;
          access_log   off;
          allow 1.1.1.0.0/24;

          deny all;
        }


 ##FILE DOWNLOAD OPTIONS  --this is the bit that is not working.
 location /path_for_testing {
            ##hosts to allow
            proxy_buffering   on;
            #proxy_buffer_size    16k;
            proxy_buffer_size    64k;
            proxy_buffers        64   64k;
            proxy_set_header X-Forwarded-Host $host;
            proxy_set_header X-Forwarded-Server $host;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_pass  http://x.y.com:80/path_for_testing;
            proxy_redirect off;
  }

##FIX CONTENT

  location /different_path {
            subs_filter_types text/html text/css text/xml;
            #subs_filter http://x.x.com/sf/ http://x.x.com/sf/ i;
            subs_filter http://x.x.com/svn/ http://x.x.com/svn/ i;
            proxy_set_header X-Forwarded-Host $host;
            proxy_set_header X-Forwarded-Server $host;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_pass   http://x.x.com:80/different_path/;
            proxy_redirect off;
  }

## Proxy the rest of the site, temporarily commented out as I am
debugging the in the path for testing section.

  location / {
            #proxy_buffering   on;
            #proxy_buffer_size    16k;
            #proxy_buffers        32   16k;
            #client_body_buffer_size 128k;
            #proxy_busy_buffers_size 64k;
            proxy_set_header X-Forwarded-Host $host;
            proxy_set_header X-Forwarded-Server $host;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_pass   http://x.x.com:80/;
            proxy_redirect off;
  }