# Profile Spring Boot with Visual VM

Today, I would like to give a quick overview of how to use  [Visual VM](https://visualvm.github.io/)  to diagnose memory leaks in a  [Spring Boot](https://spring.io/projects/spring-boot)  application. Debugging memory leaks is a critical skill to have when developing enterprise-level applications. These types of issues can take days or weeks to cause serious errors, but you will be happy to know how to isolate them when they do occur!

## Download Visual VM
First, go over to the [ Visual VM website ](https://visualvm.github.io/download.html) and download the application zip. It is a standalone application so you do not need to install it. Unzip the files someplace convenient. 

## Setup
In this step, I am going to assume that you can run your  [Spring Boot](https://spring.io/projects/spring-boot)  application from the command line. If you do not have your own application you can check out my  [spring boot memory leak project](https://github.com/fourgates/spring-boot-memory-leaks)  to follow along. If you <3 containers like me and have docker installed, simply run the following command:

```
docker-compose up profile
```

Else, you can run the Spring Boot app as you normally would. Once you are able to run your application from a terminal we need to pass some  [JVM arguments](https://stackoverflow.com/questions/30069643/remote-monitoring-with-visualvm-and-jmx)  to allow  [Visual VM](https://visualvm.github.io/)  to profile your application and help you detect memory leaks:

```
mvn spring-boot:run -Dspring-boot.run.jvmArguments="-Xdebug -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=9010 -Dcom.sun.management.jmxremote.rmi.port=9010 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.rmi.server.hostname=localhost"
```
NOTE: you can replace localhost with the IP address of a remote server if you are not profiling locally. 

## Profiling with Visual VM

Finally, navigate to the unzipped application folder and execute the`visualvm` file which is located in the binary folder (`bin`). Make sure your  [Spring Boot](https://spring.io/projects/spring-boot)  application is running and click the "Add JMX Connection"  in  [Visual VM](https://visualvm.github.io/). Next set the connection to `localhost:9010` (or whichever host you used) and click ok. There should now be a colored icon on the left-hand side which indicates you are connected to your app! If it is greyed out that means there is an issue with connecting  [Visual VM](https://visualvm.github.io/)  to your application. Double click the connection and we can now investigate memory leaks!

I will be posting some real-life examples of how to find and FIX memory leaks! Keep an eye out! Happy debugging!


![jmx-connection.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1598912495459/atX66jNuj.png)


![jmx-connected.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1598912526735/Q4FaaFZA2.png)

## Continue Reading
Take a look at my next blog post to learn more about  [profiling thread related memory leaks](https://pninan.hashnode.dev/thread-related-memory-leaks-in-spring-boot)  in a  [Spring Boot](https://spring.io/projects/spring-boot) application. 

## Shoutout
I was just like to thank [Runtik Wankhade](https://twitter.com/WankhadeRutik) for developing  [this super useful tool](https://github.com/rutikwankhade/CoverView) for creating blog cover photos. Give it a try!