We are having an online examination system already developed in Spring MVC along with live webcam image capturing and uploading for offline proctoring, now clients are demanding for online or live proctoring solution where an online proctor will see the live images of an online candidate and based on that (if any malpractice he/she feels) can send warning messages to the online candidate.
To send warning messages from online proctor to candidate we are thinking to use Apache kafka, so message from online proctoring server (Spring Boot) will go to kakfa server and each exam server (Spring MVC) will consume the message. We are clear till this point but after receiving the message at exam server how to show that message to a particular candidate without refreshing or doing REST call from browser to exam server? or is there any other elegant way to do this?

