title: Nginx response 414 URI Too Long even with very large large_client_header_buffers setting
body: <p>I am using <code>nginx version: nginx/1.10.1</code> and proxy to Rails app. I need to accept a very long URL and I update it with </p>
  
  <pre><code>client_header_buffer_size 512k;
  large_client_header_buffers 4 512k;
  </code></pre>
  
  <p>But this only works for URL length around 8'000 characters. URL with more than that will not work.</p>
  
  <p>I tried to put these header settings into <code>http {}</code> and <code>server {}</code> block, but does not work.</p>
  
  <p>Did I miss anything? It should work according to Nginx's doc <a href="http://nginx.org/en/docs/http/ngx_http_core_module.html#client_header_buffer_size" rel="nofollow">http://nginx.org/en/docs/http/ngx_http_core_module.html#client_header_buffer_size</a></p>