timer_resolution / $request_time

[Xavier Martin]

Hello,

I've been using this settings for a while:
timer_resolution 100ms;
log_format combined_time '$remote_addr - $remote_user [$time_local]  '
                   '"$request" $status $body_bytes_sent '
                   '"$http_referer" "$http_user_agent"'
                   ' $request_time';
access_log /var/log/access.log combined_time;

Right now i'm needing more precise timestamp in logs
=> finding requests that took less than 50ms to complete.

I would like to know what are the drawbacks of using a lower number
(i.e 10ms, 0ms or not setting at all timer_resolution) and overhead that would cause (if any).

thanks

-xavier