@Bobby Harsono - Some processor may be designed to utilize memory outside of the JVM. Some of the scripting processor like ExecuteProcess or ExecuteStreamCommand are a good examples. They are calling a process or script external to NiFi. Those externally executed commands will have a memory footprint of their own. - Listen type processors like ListenTCP or ListenUDP is another example. These have memory footprints both inside and outside the NiFi JVM heap space. These processors can be configured with socket buffer which is created outside of heap space.- - Thanks, Matt ... View more