Disaster avoidance mechanism for content-delivering service

Many software applications have been developed on client-server and web-based architectures, with client software installed in numerous clerks’ devices spread over the whole of Taiwan along the hierarchical organization of large-scaled service companies. The damage for a large-scaled service company would be caused by an inconsistent system, in which client software fails to receive updated content causing loss of emergency calls and possibility of recovery. Therefore, a reliable content-delivering service is needed for such a large-scaled service company to ensure system consistency whenever a disaster occurs. This study analyses the error situations of a proposed content-delivering service that has been implemented in a large-scaled company in Taiwan. Moreover, its disaster avoidance mechanism provides a reliability model with the waiting-time distribution of disconnected links. The proposed disaster avoidance mechanism prevents damage from terminating operations of a company caused by disasters, such as earthquakes, tsunamis, nuclear plant explosions or war. Empirical results demonstrate that the proposed design run on 19 servers distributes content with less than 3.4 content delivery failures per million hours.