STALE responses taking as much as MISS responses

[joao.pereira]

Just to add more information, I also have:

proxy_cache_use_stale   error
                                timeout
                                invalid_header
                                updating
                                http_500
                                http_502
                                http_503
                                http_504
                                http_404;
proxy_cache_background_update   on;

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,282984,282985#msg-282985