http://www.oracle.com/technetwork/java/performance-138178.html#
http://www.oracle.com/technetwork/java/gc1-4-2-135950.html
http://www.oracle.com/technetwork/java/javase/tech/index-jsp-140228.html
http://www.oracle.com/technetwork/java/javase/gc-tuning-6-140523.html