the UI for JVM monitoring

the UI for JVM monitoring

– the UI for JVM

The jcmd  is a great -line tool but is a bit raw. , the JVM to yield to and,inthe UI for JVM monitoring, the CPU and . and are two such tools with the JDK (not the JRE). Since both are , we will only deal with in this ,but most of the and tools can be used with as well.

Tothe UI for JVM monitoring, you just have to a of the same name:

$ $JAVA_HOME/bin/jvisualvm

Once ,you will see the of :

To start using, you will need to a JVM. This is done the tree on the left-hand side of the . The two are Local and . In this case,we’ll run the on our localjava command not, so it is by (just to start it from the same JDK as the one the is using). In the , you can see three :

Once you have your in the list, you need to -click on it and you will get the high-level about the :

Once you have a JVM on the left, the right pane will show about the JVM. It is in tabs:

The is in the -right and uses to help this view to be : green for , for , for wait, red for fork, and for .

What is are the green . This is when a does . If you take the http-(x) for , you can see that they are and green. The part is when the are for and the green part is when they are . This view must be with the dumps (or stack view) to that the are for (such as for some I/O), which the does not .

This view is close to the GC of jcmd; you’ll find the class name,the size in bytesjava command not, and the of . You can the at the using any to your ; in this , we by Quote.

If you some CPU , the view is on the and their time:

The first is the and the other show the time for the . Self Time is the time of the . Self Time (CPU) is the same but time (locks and so on). Same goes for the Total Time . What is the main the Self Time and the Total Time ? The Total Time calls, which the Self Time don’t.

While on the CPU view,you can click on Dump to get a dumpjava command not, the same as for  jcmd but it is in .