Not sure if you're asking about restarting the O/S or restarting ThingWorx, but either way, ThingWorx runs under Apache Tomcat, so restarting the system/service, restarts Tomcat.
Not sure if you're asking about restarting the O/S or restarting ThingWorx, but either way, ThingWorx runs under Apache Tomcat, so restarting the system/service, restarts Tomcat.