I have captured network package by Wireshark and found there are too many package path when sending a little StatisticalSampleResult data. It used up network bandwidth during high load performance testing.

There is an article told that serialization is very easy to send more data than is required.To solve the performance problems associated with making a class Serializable, the serialization mechanism allows you to declare that a class is Externalizableinstead.

Ref: http://archive.oreilly.com/pub/a/onjava/excerpt/JavaRMI_10/index.html?page=5