An Improved Decision Trees Updating Algorithm in Grid AC Cache Mechanism

In grid environment, PMI (privilege management infrastructure) runs as grid services. Whenever a user accesses a resource, PMI calls his/her AC (Attribute certificate) from LDAP server (a grid service) one or several times. In order to improve the efficiency of accessing AC, an AC cache mechanism is proposed. After discussing the effects brought by the hit ratio of the cache to the system performance, based on probability theory, we defined the AC as often-use-AC and not-often-use-AC, and with the improved decision tree update algorithm, we exclude the not-often-use-AC from the cache to guarantee the hit ratio. The theory and experiment all show that the method is effective and the performance of the PMI is improved.