config

Nginx 504 Gateway Timeout

504 Gateway Time-?out|upstream timed out.*reading response

Fixes

1.Increase proxy_read_timeout (default 60s): proxy_read_timeout 300s
2.Optimize the backend endpoint that's taking too long to respond
3.Add proxy_buffering off for streaming endpoints, or increase proxy_buffer_size for large headers

nginx504timeout

502 Bad Gateway|upstream prematurely closed connection

•Verify the upstream server is running and listening on the expected address/port
•Increase proxy_read_timeout and proxy_connect_timeout for slow backends

rewrite or internal redirection cycle|return 301.*too many redirects

•Check for conflicting rewrite rules that redirect back and forth (HTTP→HTTPS→HTTP)
•Use 'return 301' instead of 'rewrite' for simple redirects to avoid rule interaction

SSL_CTX_use_PrivateKey.*failed|cannot load certificate

•Verify the certificate file path and that nginx user has read permission
•Ensure the certificate file contains the full chain (server cert + intermediates) in PEM format