Troubleshoot 502 Bad Gateway
Problem
I'm using nginx and the error log is showing the following message:
[error] 6890#0: *15355 upstream sent too big header while reading response header from upstream,
client: 203.0.113.2, server: subdomain.example.com,
request: "POST /en/install/step4 HTTP/2.0",
upstream: "https://subdomain.example.com:7081/en/install/step4",
host: "subdomain.example.com",
referrer: "https://subdomain.example.com/en/install/step3"
Cause
A request cannot be processed by the proxy server because of insufficient buffer size.Resolution
Plesk
If using Plesk, see: https://support.plesk.com/hc/en-us/articles/214028909-Websites-are-unavailable-with-502-Bad-Gateway-upstream-sent-too-big-header-while-reading-response-header
If using Plesk, see: https://support.plesk.com/hc/en-us/articles/214028909-Websites-are-unavailable-with-502-Bad-Gateway-upstream-sent-too-big-header-while-reading-response-header
To increase the buffer size follow the steps below:
- Increase 'buffers" and 'buffer_size' in
/etc/nginx/nginx.conf
underhttp {
section. For example:proxy_buffers 8 16k;
proxy_buffer_size 32k;
fastcgi_buffers 8 16k;
fastcgi_buffer_size 32k; - Restart
nginx
service