A Flexible Schedule Reservation Scheme for Real-Time Service-Oriented Architecture

This paper studies a flexible scheduling data structure that is used to manage out-of-order service requests in real-time service-oriented architecture (RT-SOA) applications. We propose a hierarchical TBTree (hTBTree) to record server availability across a hierarchy of time intervals with different degrees of time granularity. Real-time services need to find enough time interval in hTBTree for their requested executions. The structure of hTBTree is designed to record only the availability of a resource during a time interval rather than the specific reserved time-slots for each request. It thus will automatically adjust existing reservations within their service intervals to make room for new reservation requests. Simulations have been conducted to study the acceptance ratio and performance of different tree-based data structures. Results show that by allowing flexibility in reservations, hTBTree can accept more real-time service requests compared with other fixed time-slot reservation scheme such as segment tree and the original TBTree. In this way, it also increases the overall system utilization.