What impact will this have if any?
We noticed it is not included out of the box for the localhost_access_log.
Release : 21.2
This parameter can be added without causing any issues to Tomcat or Spectrum.
To add hostname to the localhost_access_logs:
Edit the $SPECROOT/tomcat/conf/server.xml file.
Modify the element(s) nested within the element(s).
Change the AccessLogValve setting to include %h in the pattern= statement.
pattern="%h %l %t %u "%r" %s %b" />
Save the file and restart Spectrum Tomcat.