Making The JVM Fly Experiences With Enterprise JVM PerformanceTuning • John Davies • GOTO 2012

This presentation was recorded at GOTO Aarhus 2012 http://gotocon.com John Davies - CTO & Founder of Incept5 @johntdavies ABSTRACT Sometimes you just know something should be running faster, but as long as it runs fast enough you leave it as-is. Then, a few clients start having interesting challenges and you realise you're going to need to start tuning the JVM to address the issues encountered. In this presentation, John will walk through two real-world performance tuning scenarios that he has encountered - topics to be covered include memory usage, object creation, I/O throttling, serialisation, benchmarking and testing. Although the majority of it is not rocket science, it can be astonishing how a few small changes can make a huge difference to the performance of a JVM application. When do you have to consider giving up object-oriented elegance in exchange for specific optimisations based on the way the JVM works? How much of an impact does object allocation have on a modern JVM? How good are developers at guessing where the real bottleneck is? Join us to learn the answers to these questions, and to gain insight into what's really involved in JVM tuning. TIMECODES 0:00 Introduction 0:27 Landing on the beach (New Zealand) 0:32 White Island (Volcano in New Zealand) 1:01 The Olgas (Australia) 1:16 Parking at the pub (Australia) 10:50 On to data processing 14:36 Strings and Collections 16:40 Strings in Java 17:24 The JVM will take care of it! 21:59 Working with byte[] instead of String 26:24 A side line... 27:31 Too much memory 29:35 Over-engineering 31:22 What's wrong with disk! 32:32 Understanding the JVM memory 42:13 Some useful tools https://twitter.com/gotocon https://www.facebook.com/GOTOConference http://gotocon.com