9.1. About Invalidation Mode
Invalidation is a clustered mode that does not share any data, but instead removes potentially obsolete data from remote caches. Using this cache mode requires another, more permanent store for the data such as a database.
Red Hat JBoss Data Grid, in such a situation, is used as an optimization for a system that performs many read operations and prevents database usage each time a state is needed.
When invalidation mode is in use, data changes in a cache prompts other caches in the cluster to evict their outdated data from memory.