Just enable WebService SOAP Message logging for a certain application and process model in your log4jconfig.xml configuration file in the configuration folder of your Axon.ivy engine/server.
Replace {application} and {process_model} in the logger name below with the name of the application and process model you want to enable the logging.
Best solution is also to add an own appender which must also have at least the threshold "DEBUG". Set also the additivity=false, so it is only logged to the WebserviceFileLog appender and not to all the appenders configured for the root logger.
<category name="runtimelog.{applicaton}.{process_model}.web_service" class="ch.ivyteam.log.Logger" additivity="false">
<priority value="DEBUG"/>
<appender-ref ref="WebserviceFileLog" />
</category>
<appender name="WebserviceFileLog" class="org.apache.log4j.DailyRollingFileAppender">
<param name="Threshold" value="DEBUG"/>
<param name="File" value="${user.dir}/logs/web_service.log"/>
<param name="DatePattern" value="'.'yyyy-MM-dd"/>
<layout class="org.apache.log4j.IvyLog4jLayout">
<param name="DateFormat" value="HH:mm:ss.SSS"/>
</layout>
</appender>
