How to log the System memory and number of thread in SpringBoot?

You can use Spring-boot actuator dependency to gather information of your application metrics.

Not everything, but you will certainly be able to find out memory and related information

Read about actuator here

https://www.baeldung.com/spring-boot-actuators

https://springframework.guru/actuator-in-spring-boot/#:~:text=Spring%20Boot%20Actuator%20is%20a,metrics%20from%20production%2Dready%20applications.