status 0 on proxy MISS

[Andreas Martin]

Hello.

I'm using nginx as proxy for an apache.
Somtimes, on a MISS, the logged status is 0, instead of 200 (or anything
else). The log format is configured like this:

log_format cache '[$time_local] $remote_addr - $request_time - '
		'$upstream_cache_status '
		'Cache-Control: $upstream_http_cache_control '
		'Expires: $upstream_http_expires '
		'"$request" ($status) '
		'"$http_user_agent" ';

The value 0 occurs for the variable $status

Has anyone any idea, what the status 0 means or why it occurs?

Kind regards


Andreas