Nginx Error "Upstream Sent Too Big Header While Reading Response Header" on CodeIgniter Application
![nginx-error-upstream-sent-too-big-header-while-reading-response-header-on-codeigniter-application](https://r00t4bl3.com/uploads/codeigniter-logo-de467c731614688424e1bc6961ed9caa.png)
Problem
I have a request from my client to update an old (~3 years) CodeIgniter application. Copied the code into nginx's root directory, configure it, and then this is the very first issue I found:
<omitted for brevity> upstream sent too big header while reading response header from upstream, client: <omitted for brevity>
Solution
On nginx's configuration file, add this php location block (location ~ .php$):
fastcgi_buffer_size 128k;
fastcgi_buffers 4 256k;
fastcgi_busy_buffers_size 256k;