You can set NCA logging after NCA has been enabled. See How to Enable Caching of Web Pages for more information.
For more information, see Using Your Assigned Administrative Rights in Securing Users and Processes in Oracle Solaris 11.3.
To permanently disable logging, you need to change the status in /etc/nca/ncalogd.conf to disabled and reboot the system. See the ncalogd.conf(4) man page for more information.
# /etc/init.d/ncalogd stop
# /etc/init.d/ncalogd start