This module lets you log the time spent processing the request excluding the time required for receiving and sending data.

The module adds a new option to your log format string: '%F'.

This is an updated clone of https://code.google.com/archive/p/mod-log-firstbyte.

This version adds the format parameter to the %F (%{s}F - seconds, %{ms}F - miliseconds, %{us}F - microseconds), the default is in seconds.

The default format was changed from microseconds to seconds, to follow the format default for %T (https://httpd.apache.org/docs/current/mod/mod_log_config.html).

apxs2 -c mod_log_firstbyte.c
apxs2 -i -a mod_log_firstbyte.la

This will add a line to your configuration file to load the module:

LoadModule log_firstbyte_module /path/to/mod_log_firstbyte.so

Just add the %F into the LogFormat directive you happen to use on your apache2 server (by default vhost_combined or combined).

Create a new LogFormat and change the CustomLog directive as per below:

LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" %D %F" combined-with-firstbyte

Or using the format:

LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" %D %{ms}F" combined-with-firstbyte

Finally, change the CustomLog directive:

CustomLog /var/log/apache2/access.log combined-with-firstbyte

The module doesn't handle requests which send Expect: 100-continue header, it tracks the time taken to respond with HTTP/1.1 100 Continue header