Why do we need a random/dynamic port?

Sometimes we want to run multiple instances of a single app on the same server. And if you want to do this then we need to assign different ports in the run time only. And for this reason, we need to allocate random/dynamic ports at app startup. So we can do the change port in the application.properties file.

Unlike the Spring MVC project where we have to manually add and install the Tomcat server, Spring Boot comes with an embedded Tomcat server, so that the applications can be hosted on it. And this Tomcat server runs on a port number and the default port number is 8080. And in the Spring Boot application, we can change the default port number in the application.properties file. Please refer to this article Spring Boot – Change Port. But what if we need a Random/Dynamic Port number? Before that let’s see why we need a random/dynamic port.