A CloudSim Extension for Evaluating Security Overhead in Workflow Execution in Clouds

Workflow scheduling algorithms for cloud environments are extensively studied using workflow management system simulators. The common criteria covered by algorithms and addressed in simulators are makespan, monetary cost, reliability, and energy consumption. Beyond these criteria, security is also a criterion and has been investigated recently. Scientific and business workflows typically handle sensitive and big data that can influence the makespan and cost significantly when a scheduling algorithm applies security services to these data. However, simulators for workflow execution do not address the overhead produced by applying security services to sensitive data. In this paper, we propose an extension for workflow simulator to support security services. We considered seven steps for measuring security overheads on workflow execution. The extension was validated by executing a real-world workflow applying three types of security services namely authentication, integrity verification, and encryption. Our extension proved useful for simulating workflow execution applying security services on sensitive data and analyzing the effects of security on makespan, cost and security criteria.