Simple Java program - profiling shows unexpected behavior

Question

Given an extremely simple java program, shown below, I start the program and profile with VisualVM.

public class test {

   public static void main(String args[]) throws InterruptedException{
      Thread.sleep(10000000L);
   }

}

As can be seen by the below metrics, something behind the scenes just keeps on ticking. What could possibly be going on behind the scenes here? I also included a screenshot of the "Sampler" memory and it looks as if a bunch of primitive arrays just keep getting created, why is this?

Answer 1

You are connected to the process with VisualVM. Obviously, it takes some work to present you with the fact that the JVM is doing some work :) In specific detail, data is being collected and sent over the JMX connection. Some garbage is created.