CacheLoaderShared was that attribute name - the forum didn't appreciate the markup.
You need to set up the cache in persistence.xml
Then you can define what should be cached using either annotations, or in persistence.xml. See table 2.1:
Read those, but they don't answer my question, though very informative.
My understanding from them is that you only cache things that don't change often, so not all the entities would actually pass through the cache. Can CacheLoaderShared be used in persistence.xml?
Sounds like I need sequoia to handle HA for persistence.