Java does not give memory back to the system very quickly per default. This blows up the memory allocated to the jvm considerably. start it with: java -XX:

Java does not give memory back to the system very quickly per default. This blows up the memory allocated to the jvm considerably. start it with: java -XX:+UseG1GC -XX:MinHeapFreeRatio=5 -XX:MaxHeapFreeRatio=15 -jar ... and the jvm will give back to the system. see http://imgur.com/a/m9Qxx http://imgur.com/a/m9Qxx