Patent ID: 7158926

Claim:
A computer program product comprising a computer useable medium having computer readable code embodied therein for modeling the availability of a cluster, the cluster having a plurality of software components and at least one node, the computer program product adapted when run on a computer to effect steps including: determining a plurality of component availability models using a repair model and a plurality of failure parameters, each of the plurality of component availability models corresponding to one of the plurality of software components, wherein the plurality of failure parameters include a failure rate, repair rate and efficacy; combining the plurality of component availability models, wherein the combining step further comprises obtaining aggregate failure rates, aggregate repair rates, and aggregate efficacies for the plurality of component availability models and wherein the aggregate failure rates, the aggregate repair rates and the aggregate efficacies are obtained for each repair mode in the repair model; determining repair rates for node and cluster reboots; and constructing an availability model based on the repair rates and the combined plurality of component availability models; wherein for each repair mode in the repair model, an aggregate failure rate is a sum of failure rates of the plurality of software components for the repair mode, wherein for each repair mode in the repair model, an aggregate repair rate is a weighted average of repair rates of the plurality of software components for the repair mode, weights being corresponding failure rates of the plurality of software components for the repair mode, and wherein for each repair mode in the repair model, an aggregate efficacy is an weighted average of efficacies of the plurality of software components for the repair mode, weights being corresponding failure rates of the plurality of software components for the repair mode.