Sometimes Nginx $upstream_response_time returns 2 values.
xxx.xxx.xxx.xxx - - [08/Nov/2017:23:43:25 +0900] "GET /xxxxxxxxxxxx HTTP/2.0" 200 284 "https://xxxxxxxxxxx" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36" "-" "0.015" "0.001, 0.014"
"0.001, 0.014" this is a $upstream_response_time. Why does this has two values?
Log format:
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for" '
'"$request_time" "$upstream_response_time"';