There are only a few vague mentions of the invalidation-interval

The best reference is in the JBoss A-MQ 7.0-beta documentation

https://access.redhat.com/node/2755451/persistence#security

The same paragraph is in the upstream docs

http://activemq.apache.org/components/artemis/documentation/

The customer wants to understand what it actually does. There is a mention of it on stack overflow saying it only deals with authorization, but even that's vague.

https://stackoverflow.com/questions/55841650/reuse-the-authentication-of-the-user-against-ldap-in-activemq-artemis?rq=1