https://www.mulesoft.com/tcat/tomcat-jvm

https://www.mulesoft.com/tcat/tomcat-catalina

https://www.mulesoft.com/tcat/understanding-apache-tomcat

http://www.vogella.com/tutorials/JavaPerformance/article.html

https://blogs.oracle.com/jrockit/entry/why_is_my_jvm_process_larger_t