Nginx - upstream sent too big header while reading response header from upstream

Nginx - upstream sent too big header while reading response header from upstream

Ошибка вида

2017/12/29 19:18:40 [error] 13716#0: *196507826 upstream sent too big header while reading response header from upstream,
client: 176.227.13.165, server: site.org, request: "GET / HTTP/1.1", upstream: "http://ip:81/", host: "site.org"

Проблема может возникнуть из-за использования CSP (content security policy). Решение - это увеличить буферы в конфиге для nginx:

http {
 proxy_buffer_size   64k;
 proxy_buffers   4 64k;
 proxy_busy_buffers_size   64k;
}