SpringBoot and Cayenne

So I'm using the example that was posted here a while ago, and I've
modified it to read from a springboot yml file. I noticed that when the
application spins up, each time a new instance of the CayenneService gets
created, the code to spin up the cayenne runtime gets called.

I have a strong feeling that's not the right behavior.  So I've moved the
runtime to a class side property and then see if it's null before
spinning up the runtime. That seems to work.

My question is, in a well behaved Cayenne based application connected to
only one instance of a database, should there only be one instance of the
runtime, and one instance of the datasource?

Also the code has a shared context, which gets overridden each time the
init method is called.  That doesn't seem like a good idea either.