1. Add new log sink for traffic log
<Please see attached file for image>
<Please see attached file for image>

2. Add
trafficlogger.detail cluster wide property to specify the output of traffic log
<Please see attached file for image>

NOTE1: If the ${response.mainpart} is not set due to exception in the service policy, the response body will be empty. ie. the traffic log may not be able to save default/custom error response.
NOTE2: The new log file can be found under folder /opt/SecureSpan/Gateway/node/default/var/logs
NOTE3: The traffic log output can be customized in cluster wide property
trafficlogger.detail, the above is just an example, the format can be changed, or add more context variables.
The output of above setting may look like,
2018-09-12T14:45:46.785+1000 INFO 19912 com.l7tech.traffic: traffic log -- start
request url --
http://markgw93:8080/testonly
request body --
here is request body
response body --
ok, this is response
traffic log -- end