One thing we may have noticed with all the examples we have been working on so far is that as we are running Hazelcast in an embedded mode, each of the JVM instances will provide both the application's functionality and also house the data storage. Hence the persisted cluster data is held within the heap of the various nodes, but this does mean that we will need to control the provisioned heap sizes more accurately as it is now more than just a non-functional advantage to have more; size matters.

However, depending on the type of application we are developing, it may not be convenient or suitable to directly use the application's heap on the running instance for storing in the data. A pertinent example of this situation would be a web application, especially one that runs in a potentially shared web application container (for example, Apache Tomcat).

This would be rather unsuitable for storing extensive amounts of data within the heap as our application's storage...