Nginx Zero Size Buffer Alerts !!

[Valentin V. Bartenev]

On Friday 26 February 2016 16:05:28 shahzaib shahzaib wrote:
> Hi,
> 
> We've many zero size buff alerts related to file_uploader.php file in nginx
> logs :
> 
> 
> 2016/02/26 12:56:02 [alert] 71067#0: *12457068 zero size buf in output t:0
> r:0 f:1 0000000000000000 0000000000000000-0000000000000000 0000000803E29F08
> 0-0 while sending request to upstream, client: 182.178.58.123, server:
> domain.com request: "OPTIONS /actions/file_uploader.php HTTP/1.1",
> upstream: "fastcgi://unix:/var/run/www.socket:", host: "domain.com"
> 
> ---------------------------------------------
> 
> Here is our Nginx Version :
> 
> [root at cw001 /usr/local/etc]# nginx -V
> nginx version: nginx/1.8.0
> built with OpenSSL 1.0.1j-freebsd 15 Oct 2014 (running with OpenSSL
> 1.0.1l-freebsd 15 Jan 2015)
> TLS SNI support enabled
> configure arguments: --prefix=/usr/local/etc/nginx --with-cc-opt='-I
> /usr/local/include' --with-ld-opt='-L /usr/local/lib'
> --conf-path=/usr/local/etc/nginx/nginx.conf
> --sbin-path=/usr/local/sbin/nginx --pid-path=/var/run/nginx.pid
> --error-log-path=/var/log/nginx-error.log --user=www --group=www
> --with-file-aio --with-ipv6
> --http-client-body-temp-path=/var/tmp/nginx/client_body_temp
> --http-fastcgi-temp-path=/var/tmp/nginx/fastcgi_temp
> --http-proxy-temp-path=/var/tmp/nginx/proxy_temp
> --http-scgi-temp-path=/var/tmp/nginx/scgi_temp
> --http-uwsgi-temp-path=/var/tmp/nginx/uwsgi_temp
> --http-log-path=/var/log/nginx-access.log --with-http_flv_module
> --with-http_geoip_module --with-http_mp4_module --with-http_realip_module
> --with-http_secure_link_module --with-http_stub_status_module --with-pcre
> --with-http_spdy_module --with-http_ssl_module
> 
> ---------------------------------------------------
> 
> We don't have 3rd party module installed with nginx. Please let me know if
> i am missing something important here which could be cause of these errors ?
> 
> Thanks in advance !!
> 
[..]

If you're using spdy, then that is known issue.  You can ignore this alert.

  wbr, Valentin V. Bartenev