we have some interesting findings with loading rules PKG into knowledgebase when using mvel2-beta6 jar versus mvel2-drools4 jar. the PKG file was built in Guvnor 5.3.0.Final which uses mvel2-drools4 jar. when we loaded this PKG file using Drools 5.3 jars and using mvel2-drools4 jar, we were getting OOM errors at around 1 GB .it would also take a very long time to throw the error. when we loaded this PKG file using Drools 5.3 jars and using mvel2-beta6 jar, we were able to load the package successfully in a lesser time and no OOM errors at the same heap size. Has anyone come across this issue? is it advised/recommended to substitute mvel2-drools4 jar with mvel2-beta6 jar in our service code when loading the rules package as well as executing the rules at runtime? or, is there a specific reason for Guvnor 5..3 using mvel2-drools4 jar( such as customized optimizations) instead of just mvel2 beta jars ? -- View this message in context: http://drools.46999.n3.nabble.com/time-loading-rules-into-knowledgebase-g... Sent from the Drools: User forum mailing list archive at Nabble.com.