Dynamic Reliability Methods for a Clustered-task Server

Server resource allocation and traffic management is a large area of research and business concern in order to ensure proper functionality and maintenance procedures. As a result, good server reliability models that can incorporate workload and traffic stress are necessary. Here, we discuss server reliability models starting from the first dynamic proposal by Cha and Lee in 2011, then move to work by Traylor and Korzeniowski that better seeks to reflect scenarios found in actual servers. We generalized previous dynamic server reliability models by allowing the channels of partitioned servers to be correlated, and for that correlation to vary over time and at random. Numerical illustrations demonstrate the dangers of erroneously assuming independence among channels, which can lead to costly and unnecessary interventions in the system. In addition, we numerically explore the effects of a variable correlation on the survival function.