I have this in config:
---
error_page 404 =400;
error_page 500 502 503 504 =500 @close_conns;

location @close_conns {
internal;
keepalive_timeout 0;
}
----

I still see 502's behind returned in '$status' - Why would this happen? I was expecting to see a 500, based on my config.
I also see 404's - which should have been transformed to 400.