if you have this error from nginx with php-fpm and output_buffers = On in your php.ini then try to increment the buffer size in nginx:
fastcgi_buffers 8 16k;
fastcgi_buffer_size 32k;

if you have this error from nginx with php-fpm and output_buffers = On in your php.ini then try to increment the buffer size in nginx:
fastcgi_buffers 8 16k;
fastcgi_buffer_size 32k;

[...] sent too big header while reading response header from upstream” error, which led me to this site. By adding the suggested lines into the http {} section of the nginx.conf file, then restarting [...]
Pingback by 502 Bad Gateway with phpMyAdmin and nginx « neverblog.net — September 25, 2010 @ 11:06 pm
[...] || links | google | antoniolorusso [...]
Pingback by upstream sent too big header – nginx error « :: blackonsole :: — April 13, 2011 @ 3:32 pm
Thanks ! very very usefull
Comment by anoman — January 21, 2011 @ 1:47 am