Every so often I see a handful of errors in my error log, such as:

connect() failed (113: No route to host)
upstream timed out (110: Connection timed out)
upstream sent too big header while reading response header from upstream

etc.

in each case, when I log the $status variable in nginx, each just shows as a 502 error. Is there any way to retrieve what the actual error is (via variable?) without having to check the error log or is that the only source for this information?

Thanks!