An efficient autonomous failure recovery mechanism for UPnP-based message-oriented pervasive services

Service discovery is an interesting challenge in highly dynamic pervasive environments such as smart living spaces. In addition to adaptation to varied environments, autonomous failure recovery and activation of services are two fundamental issues of a service discovery protocol in order to achieve high service availability. We have introduced an enhanced version of UPnP´s simple service discovery protocol (SSDP), which aims to fulfill these two fundamental issues. However, our experiences in the previous work show that the failure recovery performance is not desirable due to the multicast mechanism used by SSDP. In this paper, we propose a supporting data structure, mapped eviction SND tree, composed of a set of specialized mapped-trees to speed up the failure recovery process. The system with this structure is aware of existing service nodes and need not to perform the discovery procedure again when failure is detected. Hence, the time for restoring the failed service is minimized. Experiment results show that the proposed approach helps reducing the failure recovery time up to 90 percent in average. Issues concerning maintenance and collaboration between the sets of internal data structures are also discussed in this paper.