where does the MBEAN server store all the metrics?

Question

I am new to JMX. I heard that MBEAN's write to MBEAN server locally. And I am wondering where does the MBEAN server store all the metrics? what happens when the MBEAN server crashes? all the metrics are lost?

Answer 1

The MBean server is just a component of your application. A regular Java object implementing the MBeanServer interface.

Most metrics MBeans are probably just storing their data in memory, like most Java objects.

Yes, the data will be lost if the server/application/JVM crashes, just like all other in-memory data, unless you have something else reading it out and storing it somewhere else.