Keep your distributed cache in sync with an outside data source by programming and installing application plug-ins for your region.
VMware Tanzu GemFire has application plug-ins to read data into the cache and write it out.
Use JNDI to maintain a connection pool that includes outside data sources.
By default, a region has no data loader defined. Plug an application-defined loader into any region by setting the region attribute cache-loader on the members that host data for the region.
Program a data loader and configure your region to use it.