Friday, February 3, 2012

Memory efficiency in java

I've encountered great resource about memory efficiency of huge java applications:$FILE/oopsla08%20memory-efficient%20java%20slides.pdf

Main points of the presentation are:

  • Representation overhead is sometimes huge
  • Representation overhead not always diminshes with data size (!)
  • Caches should have bounded size
  • Many tiny strings consts you more than you think

Upon reading this paper you will

  • Understand why your simple, low scale java app takes 2GB RAM
  • How to use memory more efficiently
  • Why and how to use good old mmap in java
  • .. have a few good ideas for refactoring

This has been a very good and interesting paper for me, despite the fact I don't like java much. There is hacking spirit and great amout of war-field experience in it. Go read it if you are java pro.