I used the quick start https://github.com/jboss-developer/jboss-jdg-quickstarts/tree/jdg-6.6.x/helloworld-jdg to test a strange behaviour of Data Grid 6.6 used in library mode inside JBoss EAP 6.4.6. The clear of the map doesn’t work if the passivation is enabled: the size is never be equal to 0 If I set the passivation to false the clear works as I expected and the result of the size method of the map is 0.