Include JRuby processing time in Puppet Server access log entries

As a operator of Puppet infrastructure I would like to identify individual nodes or Puppet API calls that are particularly expensive in terms of JRuby processing time. This will allow me to eliminate expensive outliers and make efficient use of JRuby availability which is the primary bottleneck for Puppet Server.

Current Behavior

The Puppet Server access log currently follows the Apache common log format with the request duration in milliseconds appended to the end:

10.32.47.186 - - [26/Apr/2018:00:39:48 -0700] "POST /puppet/v3/catalog/pe-201810-master.puppetdebug.vlan?environment=production HTTP/1.1" 200 1655399 "-" "Puppet/5.5.1 Ruby/2.4.4-p296 (x86_64-linux)" 21014

Desired Behavior

The duration should be followed by the number of milliseconds that a JRuby was borrowed to service the request, or a "-" character if no JRuby was used:

10.32.47.186 - - [26/Apr/2018:00:39:48 -0700] "POST /puppet/v3/catalog/pe-201810-master.puppetdebug.vlan?environment=production HTTP/1.1" 200 1655399 "-" "Puppet/5.5.1 Ruby/2.4.4-p296 (x86_64-linux)" 21014 17490

10.32.47.186 - - [26/Apr/2018:16:00:07 -0700] "GET /puppet/v3/environment_classes?environment=production HTTP/1.1" 200 124935 "-" "Apache-HttpAsyncClient/4.1.2 (Java/1.8.0_171)" 6767 -