In order to enhance the security of web service as well as to support the differentiated service

the paper puts forward an adaptive model which is based on active defense strategy.It uses a predictive network model on base of self-similar sequence theory to estimate current states of transfer servers in end-system

then classifies them with Fuzzy-C-means clustering method. Finally we bring forward a load balancing algorithm that is founded on the classification results and grading users' requests.In that way

it optimizes the allocation of system resources and ensures data security and reliability.Moreover

this model

not dependent on the original operating system

is transplantable and extensible.