Agent-based accountable grid computing systems

Accountability is an important aspect of any computer system. It assures that every action executed in the system can be traced back to some entity. Accountability is even more crucial for assuring the safety and security of grid systems, given the very large number of users active in these sophisticated environments. However, no comprehensive approach to accountability for grid systems presently exists. Our work addresses this inadequacy by developing a comprehensive accountability system driven by policies and supported by accountability agents. In this paper, we first discuss the requirements that have driven the design of our accountability system and then discuss the key elements of our accountability framework. We also show how accountability data can be used to detect anomalies performed by exploiting resources, such as computing power and/or network bandwidth, etc., made available by grid systems and then protect systems from these malicious actions. A model for optimizing a time frequency to monitor a queue usage is introduced as an example to be used in the initial step of the detection against the anomalous usage patterns of a monitored object. We describe a fully operational implementation of our accountability system and report the results from extensive experimental evaluations of it. Our experiments, carried out using an emulated laboratory test-bed, demonstrate that the implemented system is efficient and scalable for grid systems consisting of large numbers of resources and users.