I guess your ACC instance is On Premise hosting, because you were asking for the log path.
So probably you are able to start a process with verbose mode. But the web.log file will be full of verbose details, and with the automatic logrotate you will have short time to keep production logs and loose important other messages. So I recommend to use it for a very short delay (let say 1 hour) or best solution, do it on a dev/tests instance server.
The command to use is:
nlserver web -verbose -tracefilter:soap
it will display the messages on the server console directly.
Otherwise, better to launch it normally as background process: nlserver web -noconsole -tracefile:web@default -instance:default -detach -verbose -tracefilter:soap (the standard command has also -tomcat -autorepair) (replace -instance:default by your specific instance name if you have several instances and needs to debug only for one).
If you prefer doing it permanently (on a test/dev server only , not production, as I recommend), please change the serverConf.xml for all instances or if needed only for a specific instance, the specific config-yourinstance.xml file, the <web args=""> attribute.
Then you edit the web.log directly on the server, or more convenient, use the ACC client user interface for displaying web.log file content with filter on specific events (Home>Monitoring page, Process list section, web@default or web@<yourinstance> link).
Well, I didn't try yet the tracefilter:soap parameter, I used to use mainly the tracefilter:wdbc (sql queries) for debugging matters. So please add a post in the ticket for your results.
Thanks, Kapil. web.log is helpful, but it doesn't contain full content of the SOAP call. Regarding Fiddler I don't need to capture AC console traffic. SOAP calls I would like to capture come from external server. So, my question is still open. Do you have any other ideas?