1. What can jvisualvm do
jvisualvm is equivalent to the upgraded version of jconsole
2. Startup method
Because it comes with jdk
cmd window enter jvisualvm
The opening interface is as follows, on the left is the running local process
After double-clicking a process on the left, the interface is as follows
The garbage collection cannot be monitored by default, and a plugin needs to be installed
3. Configure the plug-in center address
View jdk version
Open the following link
http://visualvm.github.io/pluginscenters.html
Find the link corresponding to the jdk version range and copy it
Update plug-in center address
Click again to check and update, no error is reported, indicating that the address is configured
4. Install the garbage collection monitoring plug-in
5. What we need to pay attention to
After restarting, you can see that Visual GC appears on the far right
At this point, we can observe the garbage collection process in real time
Through the following comparison, we can see that the time of full GC is much longer than that of YGC
In addition, the monitoring interface is also what we need to pay attention to during stress testing.
You can look at the CPU usage, heap memory usage, heap size and used number, number of classes and number of threads to determine where we need to tune, such as often stuck in cpu calculations, or memory is often easy Full, or the number of threads is not enough to run too slow
It can be seen here that the cpu is still very idle
Later, we will analyze it in detail through pressure testing.